The first single-pass SWRO plant, Bermuda

Polymetrics’ installation of the first commercial single-pass SWRO plant in 1974 was, like many desal firsts, a daring gamble that might easily have failed to pay off.

One of the few known photographs of the pioneering BAS SWRO plant. – Dave Laker

By 1974, brackish water RO had become a commercial technology, but many still believed that it was simply impossible to make a membrane that would work for seawater desalination. Eventually, however, DuPont had unofficially let it be known that they had a viable seawater membrane. Based on that little more than hearsay, the co-founder of Polymetrics, Dave Grunau, a personality, a character and a salesman supreme, sold a system using this new membrane to Bermuda Aviation Services.

Dave Laker, who was with Polymetrics at the time, recalls, ‘We had to design the plant using the best guesses we had on the membrane specs. We used the only pump available that could produce the required feed pressure. Although it wasn’t a particularly good pump, it was literally the only one available. And, Dupont had to ship the 4-inch diameter membranes directly to Bermuda where we installed them in the system, to meet the required schedule.’

Nonetheless, the single-pass system was successful, and produced 7.6m³/d of fresh water.

Bill Andrews, a resident of Bermuda, had just joined Polymetrics, and spent much of his initial time with the company making sure the unit continued to operate.