'Toxic river water enters groundwater'

Major cities and industrial zones across the country have been set up on the banks of rivers to avail access to drinking water.

Once a lifeline of cities, the rivers have now turned toxic due to continual dumping of waste. On top of that, toxic water now enters groundwater, penetrating through the riverbed.

A major portion of our drinking and irrigation water comes from groundwater. As a result, poison is now entering the human body through food intake and causing deadly diseases.

People concerned said once toxic water flows into the groundwater, it is very difficult to purify. The government should take measure immediately and on priority basis to free the rivers from contamination.

Tuesday marks World River Day. The theme of the day is “waterways in our communities."

Last March, an article was published in the international science journal Heliyon after reviewing 283 researches conducted over the last 40 years.

Md Jamal Uddin, a teacher of the department of soil and environmental sciences at University of Barisal, and Yeon-Koo Jeong, a researcher of Kumoh National Institute of Technology, South Korea, co-authored the article titled “Urban river pollution in Bangladesh during last 40 years: Potential public health and ecological risk, present policy, and future prospects toward water management”

According to the article, rapid urbanisation and industrialisation is happening in the country along with the advancement of economy. But there is little done for environment protection and waste control. A large portion of waste from various sources is dumped into rivers. Buriganga, Turag, Balu, Dhaleshwari, Shitalakshya, Karnaphuli, Karatoa, Teesta, Rupsha and Meghna rivers are becoming more polluted, the article observed.

Speaking to Prothom Alo, Md Jamal Uddin said, “Rivers in our country have now turned toxic after getting polluted. Since river water enters at the groundwater level, it will create severe problem for public health in the long run. And it is found when the government takes measures, pollution drops and when the government remains inactive, pollution rises.”

According to the article, these toxic materials have mixed with the food cycle causing various diseases including high blood pressure, cancer, respiratory and eye problems. People living in Asia suffer from water-borne diseases more than elsewhere in the world and Bangladesh is one of the countries topping the list.

Among the major sources, untreated industrial and urban household waste is being disposed of into river. Particularly, all waste is dumped into rivers surrounding Dhaka, Narayanganj, Narsingdi, Gazipur, Chattogram, Barishal and Rangpur.

Besides, waste discharged from leather factories of the tannery estate and textile and apparel factories in Savar and heavy industries in Gazipur and Mymensingh is concentrating heavy metals.

The natural flow of river in urban areas has been obstructed due to the construction of various installations including roads, bridges and culverts. In many places, rivers are getting blocked and waste is piling up.

A research, conducted by Matin Uddin Ahmed, professor of geology at University of Dhaka in 2018-19, found groundwater containing heavy metallic toxicity in big cities like Dhaka. He ran tests on the water of tube wells and deep tube well sin Hazaribag, Sadarghat, Savar of Dhaka and Gazipur.

Speaking to Prothom Alo, Matin Uddin Ahmed said groundwater supplies most of the drinking water in big cities including Dhaka. Once toxic water enters groundwater level, it is very difficult to purify this water. So the government should take effective measure immediately to free the rivers from pollution with utmost priority, he added.

According to the department of environment, disposal of liquid waste increased to 34.90 crore cubic metre in 2021 from 21.70 crore cubit metre in 2016 in the country.

The Savar Tannery Industrial Estate alone sees a disposal of 40,000 cubic metres of liquid waste and 332 tonnes of solid waste to Dhaleshwari a day. The major polluters are the cement and fertilizer factories followed by industries including textiles, pharmaceuticals, plastics, petroleum and metal works.

*This report appeared in the print and online edition of Prothom Alo and has been rewritten in English by Hasanul Banna