Ho Chi Minh City’s authorities have approved in principle a plan to replace the increasingly-polluted Saigon River with a nearby reservoir as one of the metropolis’ main sources of water.

The plan has been submitted to the Ministry of Construction for approval, according to the Sai Gon Dau Tieng Water Supplying Joint-stock Company.

The project would guarantee a clean water source for the city’s water plants, including the major Hoa Hiep Water Plant, an affiliate of Saigon Water Corporation (Sawaco), the southern commercial hub’s water utility provider, the company said.

As one of the project’s initiators, Nguyen Hong Binh, former director of HCMC Irrigation Department, said pollution in the Saigon and Dong Nai rivers – two of HCMC’s main water sources – was increasing quicker than expected.

The city therefore should not only begin pumping water from Dau Tieng Reservoir but also think about doing the same with the Tri An Reservoir in Dong Nai, another province adjacent to the southern city, Binh suggested. Tri An currently supplies the Tri An Hydropower Plant.

Although it is currently more economical to procure water from the Saigon River than the reservoirs, water safety should still be the top priority, according to lecturer Ho Long Phi from the HCMC University of Technology.

A report by HCMC Environment Protection Agency on Tuesday showed that the Saigon River’s microorganism concentration was now up to ten times higher than the level officially set for surface water before treatment.

The water quality also failed organic compound and organic pollution tests, according to the report, adding that the same was true of the Dong Nai River, which mainly provides water for Thu Duc District.

Real threat

Since it was put into operation in mid-2004, Hoc Mon District’s Tan Hiep Water Plant has been working at overcapacity due to over-pollution in the Saigon River. With the overload a clear threat to safety, experts say there have been four separate occasions on which the facility has nearly broken down entirely.

Early 2005, salinization in the river was so bad that Hoa Phu Pumping Station, which sends water to Tan Hiep, had to halve its capacity from more than 300,000 cubic meters a day. Dau Tieng Reservoir was then ordered to release water to desalinize the river.

Following the salinization, the river was found polluted with manganese and iron content in amounts ten times above legal limits in 2006. This urged Tan Hiep to adjust its water treatment process.

The next year, the Saigon River’s ammonia content was ten times higher than the legal limit. The city then ordered the plant to use more chloride to treat the water.

Bui Thanh Giang, director of Tan Hiep Water Plant, then warned “there will come a time when pollution forces the plant to decrease its output, or stop altogether.”

In July this year, Philippine-invested pig-breeder San Miguel Pure Foods Vietnam was found discharging over 230 million liters of untreated wastewater into the river via a rupture in the banks of its 7.7-hectare reservoir.

This pushed the waterway’s ammonia content to a record high - over 3 milligrams per liter – meaning that Sawaco had to double the amount of chloride it used at its affiliate treatment plants.

Tan Hiep said it used 846.5 tons of chloride for water treatment last year and 446.8 tons more over the first half of this year.

However, pollution in the Saigon River will increase due to wastewater released from the increasing number of industrial zones and factories along the waterway, local experts and scientists have warned.

Source: Tuoi Tre