CHENNAI: Amuch-needed monsoon has been left behind. A parched summer awaits us. But, pipes in the city are gurgling with rust-particled water, making the elixir of life now a sparsely available commodity.
India is suffering “the worst water crisis in its history”, according to a June 2018 report by government policy think tank NITI Aayog. According to the World Economic Forum, Chennai needs 800 million litres of water a day to meet demand for water. But almost 50 per cent of the water pipes that snake through the city are more than 40-50 years old.
Loss of water during transmission from reservoirs and treatment plants to houses are one of the major reasons for water wastage, say experts. But, this can be prevented to a large extent by a simple change in the type of pipes used.
Shift in type of pipe
The age-old pipes in use are usually made out of galvanising iron (GI) and the more recent pipes are made from polyvinyl chloride (PVC). Technical experts shared that if the entire existing water and sewage pipe system is replaced with high-density polyethylene (HDPE) pipe, which is more durable and less prone to leakages, water loss can be cut down drastically.
“Localities like Saligramam, Nesapakkam and Ramapuram are fitted with PVC pipes. These pipes are more prone to underground seepages which are very hard to identify. In the case of HDPE, losses due to corrosion and leakage is extremely low,” said an engineer from a water technology company.
Experts also said more attention must be paid to the age of the pipe rather than the extent of transmission loss. For example, a new pipe with 20 per cent leakage is easy to repair rather than an old pipe with 60 per cent leakage in the same line. “Usually, poor operation and maintenance is the cause of leakages in new pipes which can be easily rectified. But, older pipes made of GI which easily corrode, need to be replaced only. Hence it is wiser to repair a pipe based on its age and not on the extent of water loss,” said Sajid Hussain, chief operating officer, Tamil Nadu Water Investment Company.
Trained manpower
The second way in which water loss can be reduced is by employing certified plumbers instead of contract labourers who lack technical training. “Workers who carry out the laying of such pipes must be certified based on their skill, but this is never the case in Chennai,” said Hussain.
He pointed out that faults and unnecessary mistakes occur as workers who lay the pipes lack technical knowledge about the type and position of pipes and nature of the terrain. “In other countries, plumbers are certified and classified under grade one, two or three based on their capability. But in India, untrained unqualified contract labourers are assigned to this task. This is a good employment opportunity for skilled work which the state must look into,” he said.
HDPE versus PVC pipes for water supplyHPDE
● More flexible as it is made up of bendable plastic making it apt for water connections
● More resistant to heat, hence suitable for locations like Chennai
● Creates a leak-free system due to its tight joint system
● These are highly resistant to metal content in water and sewage hence corrodes slower than PVC pipes
● Long-lasting in nature due to high resistance to abrasion and corrosion
● More suitable for household connections as can work better with low pressure
PVC pipes
● Stronger than HDPE pipes, but less flexible
● They are available in six or 12 metre length only, leading to more joints prone to leakage
● PVC pipes more suitable for high-pressure water flow
● Lesser durability