Desalination important to providing potable
water to Bahamians, Minister Roberts says:


Bahamas Information Services -
Nassau, Bahamas:


NASSAU, The Bahamas – Minister of Works and Utilities the Hon. Bradley Roberts said recently that by using Reverse Osmosis, the Water and Sewerage Corporation is now able to deal with the one major problem that impacted the Bahamian environment: excluding salt from potentially potable water.

“With continuous improvement in water treatment technology today, we have another option, which is desalination, whereby through various processes, salt and other particles, are removed from seawater,” Minister Roberts said. “Desalination in the Bahamas today is usually provided by the specific process known as Reverse Osmosis, and by this means we can provide ourselves using our abundance of pristine seawater as a source. It is more costly than the natural options, because it is usually an energy intensive operation.

“In almost all our islands, we have had to start to make use of the desalination method in order to cater to the demands of our visitors and ourselves. Even slightly brackish water – ‘which is not in itself a threat to our health’ – is not now acceptable. We all want and demand high quality, pure water. ”Minister Roberts was addressing the Rotary Club of West Nassau at their luncheon meeting on the topic “The importance of clean water in the provision of piped water in the Bahamas.”

He said that, from a Bahamian perspective, provision of piped water as a utility operation, has been very much neglected, mainly because it was always easier to use a simple rainwater tank or shallow well, which would suffice for a household’s basic needs. This has now resulted in a proliferation of private wells, Minister Roberts said, which provides a supply; but raises the question on the quality of water.

“Our tourism business in these times demands high quality water supplies, and we ourselves have raised our standards so that only water that is regarded as “bottled water” quality is all that is acceptable for drinking,” he said. “If there is any major adverse incident, God forbid, like someone dying from drinking water in the Bahamas, no doubt this will have a rippling effect and is unlikely that we will stay in the tourism business for long.”

Minister Roberts said that through most of the 20th century, The Bahamas could only make use of water that was obtained from natural sources or rainfall collected below ground level overtime. This groundwater interfaces with sea water level and literally floats in “a delicate balance,” with groundwater quality varying from rainwater to fresh to brackish to seawater.

“If it was just brackish water that was available, we had to make do with that,” he said. “As far as treatment of this water was concerned, this was minimal and may or may not have included chlorination which is used to kill off any living organisms.” Minister Roberts said that the Water & Sewerage Corporation has brought more than one dozen Reverse Osmosis Plants into operation, supplying quality water on 10 of Bahamian Family Islands including New Providence. The other locations are Ragged Island; Bimini; Inagua; Great Exuma; South and Central Eleuthera; Moores Island; Abaco; San Salvador; and Staniel Cay, Black Point; and Farmer’s Cay, Exuma. “I am now in the process of bringing similar sources of supply to another four Islands, which would include Green Turtle Cay, Abaco; Acklins; Long Cay and Sweetings Cay, Grand Bahamas,” he said. Minister Roberts said that while reverse osmosis does remove micro-organisms and chemicals from water, that is not enough.

“The World Health Organization (WHO), whose policies we abide by, emphasizes the need to use chlorine because this has a residual effect and continues to disinfect,” he said. “It is a WHO requirement that we must chlorinate the water that goes into our distribution systems, so that there is a constant process of disinfection to prevent recontamination of the water.

“Bottled water is usually only treated by ozonation or ultraviolet and it is then up to the user to ensure it stays good. Sometimes, it does not.” “Many of you may not like the faintest trace of chlorine in the drinking water, but I’m afraid we must have it, according to the WHO,” he added. Minister Roberts said that, besides chlorinating the water, modern utility companies are also obliged to monitor the quality of the water in their piped water system. For every so many thousands of persons supplied, water quality must be tested in a laboratory a given number of prescribed times, every day.

“This is what the Water and Sewerage Corporation does – some 300 samples are taken every month and tested in New Providence and this requires some 6,500 separate analyses,” he said. “These tests are also carried out in the Family Islands but of course, the frequency is reduced for logistical reasons. The Public Analyst also tests the water on a similar frequency; so it is always quick to tell the Corporation, and other suppliers and private well users when the water fails the required tests.”

Providing piped potable water is not a simple task, Minister Roberts said. The procedures that are involved have developed over many years and no doubt they will continue to evolve into the future. “For this reason, we always need to keep abreast of current thinking, and technology,” Minister Roberts said. “Well-educated and trained staff will always be required in the water supply business and the current administration strongly acknowledges this.”

08/25/2006

health