LONDON — As global climate change brings more-severe drought conditions to many parts of the world, a young British company has created giant plastic bags in which to ship and store huge amounts of fresh water more efficiently.
London-based Aquarius Water Trading & Transportation Co. Ltd. has designed and built a number of the 216-foot-long barge-shaped bags, made of welded sheets of Panama-weave polyurethane.
After successful sea trials off Britain and in the Mediterranean, Aquarius has won Greek government contracts, together worth £1 million ($1.63 million), to supply water to two communities on the Greek island of Aegina beginning this month, according to Aquarius Managing Director Simon Pratt.
The British firm, which sees great potential for its floating reservoirs in Greece, has bought its own tug and will use three of the 190,000-gallon bags to ship water the 14 nautical miles from the Greek mainland port of Piraeus to Aegina. There, the water will be piped to hilltop tanks for distribution.
Plastic material for the bags is being imported in 61/2-foot-wide sheets from U.S. supplier Cooley Inc. of Pawtucket, R.I., Pratt said. The 4-millimeter-thick sheet, with food-grade coating inside and ultraviolet coating outside, is cut and radio-frequency welded into a bag.
The 26-foot-wide bags, filled with water through valves mounted at the front and rear of their flat ``decks,'' are designed to replace old and rusty tanker ships used to supply arid territory.
The bags can be towed, singly or in pairs, by tug at sea. Equipped with buoyancy chambers to stay upright, each bag floats with its flexible ``belly'' fully submerged when loaded.
These floating reservoirs, with a shallow, 61/2-foot draft, can be moored offshore or in shallow water for storage and discharged by pipe to land-based tanks for supplying the population.
The company's concept already has attracted interest from other parts of the world, including the currently drought-stricken British water companies. But Aquarius will need to develop still-bigger bags to handle the amounts of water required by larger communities before its product is viable there, Pratt said.
The firm is working to develop bags of more than twice the size of its current versions. Pratt said he expects to have 500,000-gallon containers ready within two or three years, with longer-term plans to build bags that can hold as much as 3 million gallons of fresh water.
The 18-month-old Aquarius and its bag concept are the culmination of a decade of design and formulation, Pratt said. He likened the bag's shape to the cross section of a rugby or American football ball.
The idea was sparked originally by plans then to ship fresh water by sea from Washington state to the drought-hit region of Southern California.
But that plan was abandoned once the drought ended, Pratt said.
Early material trials included testing small mock-up PU bags on a Scottish loch.
``We needed a flexible material — something that will move with the waves and transfer the force of a wave through the bag and out the other side, rather than being resistant like a conventional vessel,'' Pratt said.
He admitted the firm was lucky in coming upon the polyurethane sheet early on. It is strong, flexible and does not degrade, giving the bags a five-year life span. Pratt said that the material already had been used successfully by the U.S. military for tank linings.
For larger fresh-water supplies, the bag concept allows for a line of big containers to be moored in a sheltered spot of a port where their cargo can be pumped ashore to static tanks or road tankers. The bags would operate like an oil terminal, the company said.
For the moment, Pratt said Aquarius will concentrate its efforts in the lucrative region of the Greek islands, where several parties have shown interest in a similar service for other arid islands, including Kos, Hydra and Poros.
``We have an office out there and we are going to use Greece as a pilot project to blueprint operations for other countries worldwide,'' Pratt said.
He added that there are many other places, including Spain, the Bahamas and Australia, where water has been transported by sea.
During the past two years, Britain has suffered its most-severe continuous period of drought since the 1800s. The first four months of 1997 were the driest start to a year for 68 years, with water courses all but drying out.
Several British regional water companies, recently privatized, have shown interest in the bag concept.
They include Anglian Water, covering the driest region of East Anglia, Southern Water and Thames Water — for which Aquarius is looking at doing feasibility studies, according to Pratt. Some companies are considering shipping water from Scotland or Norway, but they also are looking at desalination or porous-rock storage methods.
Aquarius is controlled by several private shareholders, but other minority investors in the company include Northumbrian Water and Hartog of Norway.