As Vietnam intends to develop a seaborne economy, it must think of solutions to treat sludge, as the volume will be increasing in the future, scientists say.
The public has once again been stunned by the news that sludge from passage dredging will be submerged in the Binh Thuan sea.
Prior to that, other coal-fired thermal power plants sought permission to sink sludge in territorial waters.
Scientists warn that the submerging may have negative impact on the environment.
Nguyen Huu Huan from the Oceanography Institute said sludge from port dredging is inevitable with sea-borne economy development.
Under the national electricity development plan, Vietnam will develop a series of thermal power plants along the coastline. Each plant will be associated with a port that serves coal transport, and the sludge from port dredging will include a large volume.
Experts say it is time to think of solutions to deal with sludge in a methodical, long-term way, experts say.
“Is it imperative to submerge sludge from dredging into the sea? Why couldn’t we treat it as a kind of resource to serve construction works and anti-landslide works in coastal areas if the sludge is not toxic?” Huan said.
He said that a lot of coastal urban areas are built every year and a series of coastal areas need materials to build breakwater and anti-landslide works.
To implement the works, an extremely large volume of rocks and soil needs to be exploited which affects landscapes and causes landslides.
Nguyen The Dong, deputy general director of the Environment General Directorate, also thinks that leveling and filling up coastal areas is the best way to treat sludge.
He said in European countries, the materials collected from the dredging are used for construction. Sometimes they use sludge to consolidate coastal areas, tide-affected and mangrove areas. The Dutch use 30 million cubic meters of sludge from dredging every year to expand its territory.
According to Huan, these could be solutions to consider. However, they need to be applied in a flexible way in Vietnam, where there is high biodiversity.
In conditions in Vietnam, if submerging unpolluted sludge in the sea, the receiving yards must have a depth of 80-100 meters at minimum to mitigate the impact on coastal ecosystems.
In Vietnam, submerging sludge in territorial waters 4-5 miles away is the most convenient and economical. But this must be seen as a last resort.