Mekong River Pollution

Cambodia announced that it will start work on the Funan Techo Canal in August. The $1.7 billion (€1.6 billion) project will link the Cambodian capital, Phnom Penh, to the sea — sparking concerns in Vietnam over its impact on the rice-producing Mekong Delta, home to 17.4 million people.

Environmentalists are also concerned that the 180-kilometer canal will potentially reduce water flow to the Mekong, among the world's most biodiverse rivers.

The climate crisis is compounding the issue, with delayed rainy seasons and heat waves further drying out fertile lands.

A comprehensive site inspection was conducted on 7 April by the MRC Secretariat, Lao National Mekong Committee, the Department of Water Resources, and the National Resources and Environmental Research Institute (NRERI). Recognizing the urgency of the situation due to the highly corrosive nature of sulfuric acid and its potential harm to living organisms, a team of experts along with provincial staff averted a potential environmental catastrophe through swift containment and remediation efforts over the weekend.

Field measurements revealed that while there were initial impacts observed at the incident site, including reduced dissolved oxygen levels and elevated sulfate concentrations, the water quality in the Nam Khan River and Mekong River remained unaffected. The implementation of barriers from local authorities and neutralization measures effectively contained the spill’s effects, ensuring minimal environmental damage.

However, the incident has raised concerns for Thai authorities, as the contamination was expected to quickly reach Thailand. Thai officials have also been in contact with their counterparts in Laos to coordinate efforts.

On the afternoon of 3 April, a truck carrying 30 tons of sulfuric acid encountered an accident in Phou Xang Kham village in Luang Prabang, resulting in a significant spill in the canal nearby. The incident occurred when the truck transporting sulfuric acid toppled over, leading to the leakage of approximately 50 percent of its contents. 

The incident site is located approximately 300 meters from the Nam Khan River and about 6 kilometers from the confluence of the Mekong River.

On the following day, local authorities erected barriers to prevent the acid-contaminated water from reaching the river, according to the Mekong River Commission (MRC).

Staff from the Kovalevsky Institute of Biology of Southern Seas of the Russian Academy of Sciences and Vietnamese colleagues have been studying the waters and inhabitants of the lower Mekong Delta (Hau and Tien Rivers) since 2018. They used trawls to take samples and also caught fish and ten-legged crustaceans, some of the most abundant inhabitants of the rivers.

"We continued our research on pollution in Vietnam's Mekong River, one of the world's top ten largest rivers, where more than 37,000 tons of plastic trash is recently estimated to be dumped annually. Up to 136 dams are to be built on it by 2030, and silt sediments may be partially replaced by plastic, creating a substrate with new properties unaccustomed to hydrations. To understand how this will affect the local fauna, it is important to assess the dynamics of plastic pollution as accurately as possible now," says Evgeniya Karpova, a senior researcher at the Ichthyology Department of the FIC InBYUM.
"Construction of dams can significantly worsen the ecological condition of the Mekong and negatively affect animal hydrations. Our study is another illustration of the need to pay attention to the problem of plastic pollution", - sums up Svetlana Statkevich, senior researcher of the Ichthyology Department of FIC InBYUM.

The United Nations Environment Programme (UNEP), the Conservation of Migratory Species of Wild Animals and several other partners have launched an in-depth study of the Mekong River Basin.

“Most of the focus on plastic pollution to date has centered on the marine environment. But we know that plastics are found in terrestrial and freshwater environments,” said Amy Fraenkel, Executive Secretary of the Convention on the Conservation of Migratory Species of Wild Animals. “We need to better understand the scale and impact of such pollution on the species in these areas, including migratory species.”

Government officials and university researchers from Cambodia, Lao People's Democratic Republic (PDR), Thailand, and Viet Nam will work together to examine plastic waste leakage into the Mekong River system.

The aim is to understand the current state of plastic pollutants in the region and offer policy recommendations to address the challenges.

According to a study on the export of plastic debris by rivers into the sea, the Mekong River was one of the 10 rivers that collectively carried between 88–95% of plastics into the world’s oceans. The Mekong River Commission also noted reports underscoring the lack of basin-wide countermeasures for the ‘plastic lifestyle’ growing across Mekong communities.

The regional workshop hosted by the Mekong River Commission and United Nations Environment Programme (UNEP) Regional Office for Asia and the Pacific in Vientiane, Laos on 11-12 February 2020 discussed assessment methodologies to study plastic debris and its sources across the Mekong.

“The assessment will provide the four Mekong countries with scientific evidence and information on plastic debris, plastic pollution, and its threat to the environment and people,” said Ms. Kakuko Nagatani-Yoshida, the UNEP Regional Coordinator for Chemicals, Waste, and Air Quality.

The Mekong is reeling from the combined onslaught of climate change, sand-mining, and incessant damming of the river, which combined to help cause the worst drought recorded in over 100 years in July.

“This is the worst ecological disaster in the history of the of Mekong region,” declared Thai natural resources expert Chainarong Setthachua.

The water level in the Tonle Sap, Cambodia's great inland lake, the “beating heart of the Mekong,” was reduced to unprecedented shallow areas with one floating village almost completely dried up.

Youk Sengleng an NGO fisheries expert stationed by the Tonle Sap shared his observations: “Many fish died because of the shallow water, hot temperature, and toxic water resulting from lack of oxygen.

Taking too much water out of a river essentially sucks the life out of it. Pollutants become more concentrated and water flows dwindle, resulting in the build-up of sediments that clog up the river bed.

The Mekong, which is also the 12th longest river in the world is known to be a major water source for drinking, fishing, and agricultural needs for millions of people. What many do not know about it, however, is that it is also a dumping ground for garbage and waste deposits making it to be one of the most polluted rivers in the region.

The pollution that is currently taking place in the region has stemmed from centuries ago. These water resources in Southeast Asia are under intense pressure because of population growth, urbanization, and climate change.

Rapid economic development and urbanization have resulted in the degradation and depletion of natural resources, including water and related ecosystem services.

According to a report by the Institute for the Advanced Study of Sustainability's Policy Brief, the pollution level in the Mekong River is high. 

The main reason is untreated household waste, which falls directly into the water bodies. According to official statistics, only 20-30 percent of urban households are connected to a sewer system. The remaining 70 percent of homes have septic tanks, which in many cases drain human waste into underground aquifers.

According to Dr. Le Trinh of the Vietnam Institute for Environmental Science and Development, many industrial areas across the country are unable to properly operate their waste treatment systems and are therefore dumping large amounts of industrial waste with high levels of toxic chemicals into the environment.

According to studies, industrial and urban wastewater has caused serious water pollution in the Mekong River. Statistics from a 2015 conference on the state of Vietnam's river network between 2005 and 2015 showed that in 2010, about 1.1 million cubic meters of industrial wastewater were discharged into rivers daily. This is estimated to increase to 2.4 million cubic meters by 2020.

On Phu Thanh Island, shrimp farmers are facing serious environmental problems related to the pollution of the Mekong River.

Unknown poisons affecting Wu shrimp are corroding all farms in the area as they pump water both into and out of the Mekong. There are fears that if the banks of the farms are eroded, 250,000 to 300,000 sick shrimp will enter the river. The consequences would be catastrophic for downstream neighbors, who would inevitably drag tens of thousands of infected crustaceans into their ponds. In the aftermath, poisoning of the water, other aquatic inhabitants, and people are expected.

A research team comprised of members from the University Network for Wetland Research and Training in the Mekong Region, the International Crane Foundation, and the USGS found that the total loading of persistent organic pollutants in wetland sediments of the Mekong Basin was generally low, but hotspot sites occurred where concentrations exceeded established ecological risk thresholds.

Persistent organic pollutants are not readily biodegradable and are known to cause a variety of toxic effects in humans and other organisms. This research focused primarily on persistent organic pollutants used in agricultural practices.

An international team studied 531 samples from approximately 450 wetlands in five Southeast Asian countries and analyzed them for 39 persistent organic pollutants—in this case, organochlorine compounds and PCBs.