Saltwater Treatment Plant Brings ‘Tasty Tea’ to Indian Island

Each morning, Kamarunisa Poovummada sips her cup of tea while watching waves from the Arabian Sea crash around a water treatment plant opposite her house on Kavaratti island, off India’s southwest coast.

She links the taste of her perfectly brewed cup to the desalination plant that has brought potable water to the doorsteps of islanders, and almost erased the memory of the brackish tea she hurriedly swallowed down until a decade ago.

“We first noticed the difference when we saw the golden color of the tea as we strained it into our cups,” Poovummada recalled. “And then we tasted the tea and it was magical.”

The “tasty” tea is celebrated daily by residents of Kavaratti, the capital of India’s smallest Union Territory Lakshadweep, an archipelago of 36 islands, of which only 10 are inhabited.

Surrounded by pristine beaches, lagoons and coral reefs, the islanders have for decades battled a shortage of clean water – a challenge facing many island inhabitants globally.

Over the years, the sea’s clear blue waters seeped into the islands’ limited groundwater reserves, making every sip saline.

Limited land availability also resulted in groundwater sources being too close to sewage sumps, causing contamination and making water unsafe for drinking, cooking or even bathing.

“The water system was a mess,” said Hidyathulla Chekkillakam, who grew up on the island and is an employee of the public works department that runs the desalination plant.

Different options were tried, from open wells to rainwater harvesting, he said – but they were either ineffective or too expensive.

“Good drinking water was a prized commodity,” he added.

Piped Dreams

When Purnima Jalihal and her team from the Chennai-based National Institute of Ocean Technology (NIOT) first arrived on Kavaratti in 2004, they were armed with blueprints for a desalination plant and cartons of bottled water.

They found themselves in the midst of a fragile ecosystem, with clear instructions from the island administration to “not destroy” anything. They were also warned about the tea, and soon found even a sip made them queasy.

“The salinity in the water was unbearable, and the people knew it was not good for their health. But they had no choice,” Jalihal said.

The project – and the fact it was headed by a woman – drew curious islanders to the site, where Jalihal’s team had to improvise designs to ensure construction did not harm the ecosystem.

“It was a struggle to get things going,” the scientist said. “There was no infrastructure and we couldn’t bring in heavy machinery. Everything had to be done manually.”

The team built floating structures and towed them into the sea, including an underwater pipeline.

In less than a year, the water treatment plant was up and running, producing 100,000 liters of potable water a day.

Pipelines were laid along the streets, with a community tap set up every 25 meters (82 ft). And in 2005, the water supply started.

“It was almost like a revolution,” housewife Rahiyanath Begum told the Thomson Reuters Foundation as she watched her children play on the beach.

“Tea is a part of our life. We drink it without milk and so the color and taste are important. If the tea is good, it means the water is good,” she said.

Poovummada, Begum and the 11,200 residents of Kavaratti – a tiny island measuring just 5.8 km (3.6 miles) long and 1.6 km wide – neatly line up buckets around the water taps for an hour each day.

Tourist Attraction

Abdul Latif is used to islanders visiting the plant to show it off to their children, and guests from the mainland.

“It’s almost like a tourist spot,” the 43-year-old operator said, smiling.

From walking visitors across the bridge to see the underwater pipeline to urging everyone to drink a glass of treated water, Latif has become a poster boy for the plant, which has withstood storms, including Cyclone Ockhi in 2017.

“It rarely breaks down, and the real challenge is when big jellyfish get stuck in the underwater pumps,” he said.

Built at a capital cost of about 50 million Indian rupees ($727,400) with government funding, the plant technology is robust, environmentally friendly and requires little effort to operate and maintain, Jalihal said.

Developed by the NIOT, it utilizes the temperature difference between sea-surface water and deep-sea water to evaporate the warmer water at low pressure and condense the vapour with the colder water to obtain fresh water.

Buoyed by its success, the NIOT set up two plants on Agatti and Minicoy islands in 2011, providing more than 15,000 residents with clean water. Construction of six more desalination plants is now underway on other inhabited islands.

Only one other water treatment plant in India, off the coast of Chennai city, uses the same home-grown technology. Others purify water with reverse osmosis, a costlier imported method.

Latif and his team work shifts to keep the motors of the plant running, to supply nine liters of water per day for each resident, including three for drinking and five for cooking.

“We discourage people from using it for a bath or washing clothes because we don’t want even a precious drop wasted,” said Chekkillakam. “Everyone understands because we have seen how quickly clean water sources dry up or get contaminated.”

Going Green

A decade after the Kavaratti desalination plant became operational, Jalihal is back at the drawing board, this time working on a new plant for the island that will draw power from the sea instead of running on diesel generators as now.

“It will be completely green, using ocean thermal energy to run. Then the system will be perfect,” she said.

Khadeeja Lavanakkal cannot wait for the second plant. She lives at the end of the pipeline, and sometimes gets only a trickle of clean water because others have filled extra buckets.

“We have an open well, but when officials come to check the water they tell us it is more saline than sea water. We could do with a little more clean water to drink.”

Nonetheless, Lavanakkal is grateful to the scientists.

“It’s not just the tea but even the curries we cook are so much tastier,” she said.

“And the best part is that we can close our eyes and drink a glass of water without worrying about falling ill.”

($1 = 68.7400 Indian rupees)
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