WATER EFFICIENCY

DRINKING WATER – ONE OF THE MOST IMPORTANT PROBLEMS IN THE WORLD According to the UN-Habitat report Water and Sanitation in the World’s Cities, pressures on the supply of drinking water will only become worse.  Where two fifths of the world’s people already face water shortages, by 2010 50-80% of people will be urban dwellers, putting ever more pressure on municipalities to provide water to an increasingly urban population.  Since the amount of water available for consumption is not likely to increase (except under energy intensive processes such as desalination and melting of glacial ice), one of the most cost-effective ways to provide better water service is by decreasing supply losses.                                                                                     

HOW GREAT IS THE REAL LOSS?Losses in water supply systems worldwide are between 10 and 80%. According to research by the European Economic Commission of the United Nations, approximately 50% of drinking water is lost during distribution.                                               

WHAT HAPPENS WITH THE LOST WATER?                                                                              Losses can be attributed to leaks and illicit connections.  Leaks occur at weakened joints or fittings or from damaged or corroded pipes.  Leaks soak the ground surrounding the pipe and can cause a pressure differential that sucks dirt and contaminants into the pipe.  Illicit connections, in addition to being an un-metered theft of municipal water, can also cause cross-connection contamination of the water supply.  Meter malfunctions can also lead to a higher or lower perception of water use than actual.   Total unaccounted for water is the difference between the amount of water produced and the amount consumed.  This is usually measured by metering the water into the distribution system and metering the water that is used by customers.                                                          

FINANCIAL COSTS CAUSED BY LOSS                                                                                          Leaks waste water and can undermine pavement and structures.  Frequently, leaks in the system end up in the sewage system, raising wastewater treatment costs.  Contamination caused by leaks and illicit cross-connections increases the cost of water treatment. Uncontrolled losses unnecessarily require high consumption of electricity for pumping. A 5-millimeter crack with 5-bar pressure causes an annual loss of 9,500 m³ water, which multiplied by 1 EUR per m³ of water results in annual financial loss of 9,500 EUR; while a 9-millimeter crack causes annual loss of 36,000 m³ of water or financial loss of 36,000 EUR under the same conditions.

WATER LEAK DETECTION EQUIPMENT

Methods to locate leaks include direct observation, such as locating damp spots that might indicate a leak.  A damp spot does not always indicate a leak and it also does not indicate the exact location of a leak.        A leak can be located as much as 50m away from the damp area on the ground surface.  Leaks can also be established using sounding rods, listening devices and data from water audits.   The following are equipment and devices that can be used to detect a leak that cannot be visually established. In some water supply systems, there are contemporary electronic devices, while ordinary, mechanical tools are still used in other systems.