Karnaphuli water salinity-
- From 2ppm to 5,800ppm between 1987 and 2020
- Affecting production of 350 industries
- Production at CUFL halted for 72 days this year
- Around Tk288cr in losses
- Production at DAP Fertiliser Company is also hit hard
- Production of WASA water treatment plant is hampered
- Cropland fertility in the areas declining
- Rising sea levels due to climate change blamed for salinity
Salinity in water up to 15 parts-per-million (ppm) is what the Chattogram Urea Fertiliser Limited (CUFL) can take to keep its production going.
But the River Karnaphuli, upon which the factory stands, is an extreme case in point as its salinity during the dry season jumps up to a staggering 5,800ppm.
The fertiliser factory now has to keep its production shut for longer periods because of the high level of salinity in the river water, its main ingredient besides gas and air.
This year, the major state-owned fertiliser company under the Bangladesh Chemical Industries Corporation (BCIC) had to stall its production for 72 days in a row from March to May.
Experts attribute this abnormal rise in salinity to the rising sea levels caused by climate change.
Other industries on the river bank are also facing severe setbacks in production, especially during the dry season from November to May, when salinity increases.
These industries largely depend on the river water for their production.
Coursing its way through the Chattogram city, the Karnaphuli has its origin in the Lushai hills in the Indian state of Mizoram and flows into the Bay of Bengal.
The CUFL is the only company in the area that measures salinity of the river water almost every hour, looking for usable water with salinity below 15ppm.
It collects around 18-20 million litres of water per day for production.
For keeping production suspended, the company has to count Tk4 crore in losses every day, officials have said. For the 72-day closure this year, the losses reached around Tk288 crore.
Japan's Toyo Engineering Corporation set up the factory in 1987. It built the water collection point 30 kilometres in the upstream at Kalurghat to have an uninterrupted supply of sweet water, considering water in the area was free from salinity.
But water there has now become saline as well, hampering livelihoods of people living nearby who depend on the river.
In 1987, the highest salinity in Kalurghat was only 2ppm.
"But now it reaches around 5,800ppm during low tide and dry season. In recent years, we could collect water only for four hours a day during high tide," said Abdur Rahim, managing director of the CUFL, who also served as an in-charge of the company's water treatment plant during the early days in his career.
"From 1987 to 2003, we could collect water round the clock. In 2007, we found a high salinity level of 4,315ppm from February to March, and it is still increasing," he added.
In 2003-04, when the company was running full-scale operations, it had to suspend production for the first time due to high salinity. That year, production was suspended 18 times for 39 days for different reasons and salinity was one of the major problems, according to a company report.
Though the factory had to suspend production for different reasons, including high salinity, in the last 15 years, it had to do so for a longer period of 72 days for the first time this year.
"We may be able to run the factory for over 10 years like this if we have to depend on the Karnaphuli water. We fear that after 10 years salinity will constantly be over 15ppm, be it during low tide or high tide or rainy season or dry season," he added.
Binoy Paul, master operator at the CUFL who has been measuring chloride in the Karnaphuli water for the past 33 years, told The Business Standard, "Salinity has been increasing every year with the rise in sea level. Salinity also increases if there is a natural disaster, such as a cyclone. Salinity is low during the rainy season and high tide."
After collecting water from the river, the company categorises it into filter water and demi water. From filter water, it gets cooling water, fire water and potable water. Demi water, on the other hand, is used in the boiler to make steam for urea production.
"Now, we are looking for sweet water. We contacted Chattogram Water Supply and Sewerage Authority and they assured us of providing 10 million litres per day within a few years. We have four deep tube wells, but we do not use those as they deplete groundwater levels," Rahim said.
The CUFL's everyday urea production capacity is 1,700 tonnes while ammonia production capacity is 1,000 tonnes. The company can produce 561,000 tonnes of urea annually.
Because of unwanted suspension of production, the company hardly achieves its yearly targets, causing the country to import more fertiliser.
Bangladesh has an annual demand of over 2.6 million tonnes of urea while the BCIC's six factories can produce around 0.8 million tonnes now. A decade ago, the BCIC factories could produce 1.8 million tonnes.
DAP Fertiliser Company, another BCIC factory, is also heavily affected by high salinity as it collects around 10 million litres of water every day from the Karnaphuli through the CUFL.
The production of Wasa water treatment plant at Mohara at the estuary of the River Halda near the Karnaphuli is also facing severe setbacks.
"We cannot supply water to city residents if the salinity is above 200ppm. During the dry season, or low tide, we have to mix ground water with the river water to make the water drinkable," said AKM Fazlullah, managing director of Chattogram Wasa.
"In 2018, we had to make an announcement in daily newspapers asking people not to drink our water," he mentioned.
Dr Muhammad Edris Ali, a Karnaphuli researcher and chemistry professor at Government Hazi Muhammad Mohsin College, told The Business Standard, "There are 350 small and big industries on the banks of the Karnaphuli. Most of them somehow depend on the river water. Some industries collect water for production and some for personal use; they all are suffering because of high salinity.
"Moreover, the amount of sweet water which is supposed to come from upstream does not come to the river. The increasing use of river water and dumping of waste are also making the water saline and polluted."
Edris Ali said, "The agricultural lands in five upazilas are losing fertility while fish farming is getting tougher because of the salinity in water."
AKM Rezaul Karim, a climate change expert and author of Climate Change and Environmental Planning, said, "The increasing salinity in Karnaphuli water is the impact of the rise in sea levels caused by climate change. High salinity is found from the Karnaphuli estuary (the Bay of Bengal) towards upstream until the mouth of the River Halda, a 55km stretch."
This will increase with rise in sea levels, he said.
"We have to formulate an adaptation policy. For example, we have to build water reservoirs for keeping rainwater or sweet water," said Karim, who is also the chief city planner of Chattogram City Corporation.