In August, workers were busy building embankments, sidewalks, and two roads along the canal as part of the work, many of which was largely complete, giving the area a new appearance, but a huge volume of sludge remained in the canal, unable to be dredged.

Nguyen Van Cuong, chief supervisor of a construction package, said: "The contractor has only removed the soil excavated from the two sides, transporting it to nearby disposal sites for use in constructing the roads and embankments. The sludge in the canal bed cannot yet be dealt with because there is no place to take it to."

A section of the Tham Luong–Ben Cat–Nuoc Len canal with embankments and two parallel roads is largely completed in August 2026. Photo by VnExpress/Giang Anh

The package covers more than eight kilometers of canal work, from Truong Dai Bridge to the Saigon River, and is one of the main components.

The section also contains some of the widest stretches of the entire canal, with some areas 100 meters across and with the largest volumes of sludge, estimated at around 1.7 million cubic meters, or nearly half the entire project's.

The work is more than 65% complete, but the dredging remains on hold because of the sludge disposal issue.

The same situation repeats across the project, forcing contractors to focus on above-ground works such as embankments, roads, sidewalks, and technical infrastructure.

The work was launched February 2023 at a projected cost of VND8.2 trillion (US$312 million), though the amount has increased since to more than VND9 trillion after several components were added.

The Tham Luong–Ben Cat–Nuoc Len canal is one of HCMC's longest canals, running through seven former districts: 12, Binh Tan, Tan Phu, Tan Binh, Go Vap, Binh Thanh, and Binh Chanh.

The project comprises 10 packages comprising dredging, concrete embankments, the two roads, 19 drainage culverts, 12 boat docks, bridges, lighting, landscaping, and other facilities.

The canal will be dredged to a depth of four to five meters to improve drainage and waterway transport by removing decades of accumulated sludge.

The work is targeted for basic completion by the end of this year, but the sludge disposal problem is threatening the schedule.

According to the HCMC Urban Infrastructure Construction Investment Project Management Board, the project manager, a total of 4.7 million cubic meters of soil and sludge are expected to be excavated.

Of this, 1.4 million cubic meters of soil will be used for on-site filling or transported to nearby disposal sites.

The dredging will generate 3.3 million cubic meters of sludge.

Under the original plan, the sludge would have been transported to Go Vap Cultural Park in the former Go Vap District and Sub-area 3 in the former Binh Tan District, but it has encountered obstacles.

Sub-area 3 is in a rapidly urbanizing area with a large population, and local residents have opposed the plan objecting to the likely pollution.

Go Vap Cultural Park is linked to another project and no longer able to accept the sludge.

Changes to regulations have also made the original plan unfeasible.

Authorities said the former HCMC has two centralized waste treatment sites, Da Phuoc in the former Binh Chanh District and Tay Bac in the former Cu Chi District.

Sludge that is severely contaminated has primarily been sent to Da Phuoc for treatment in recent years. But the city has no designated disposal sites for non-contaminated soil and sludge.

Thus, project managers must find appropriate sites themselves, reaching agreement working with local authorities before beginning a project, something that often takes time or is rejected.

To resolve the issue, the Tham Luong managers are considering a new approach rather than find a disposal site.

Workers construct sidewalks and a road along the Tham Luong–Ben Cat–Nuoc Len canal in HCMC in August 2026. Photo by VnExpress/Giang Anh

Vo Viet Cuong, an official at the HCMC Urban Infrastructure Construction Investment Project Management Board, said the plan is for the "recovery of Group IV minerals" from the sludge.

Under it, the city will auction more than three million cubic meters of sludge, with the winning bidder arranging their own machinery and equipment for dredging, and transporting and treating the sludge.

The city's Department of Construction has agreed with the proposal.

Pham Viet Thuan, director of the HCMC Institute of Resources Economics and Environment, said dredging rivers and canals is essential for an urban area but there must be adequate sites for storage and treatment of sludge.

In the past, sludge from the Nhieu Loc–Thi Nghe and Tan Hoa–Lo Gom canals was mainly treated and used for landfills or repurposed on site for planting green buffers.

Some private companies offered sludge treatment services, but their costs were too high to meet the city's long-term needs.

With the city preparing to renovate a number of canals, including Xuyen Tam, the northern bank of Kenh Doi, and Van Thanh, Tuan said it should quickly designate sites for receiving and treating sludge and proactively manage the system.