Tran Thi Kim Van, deputy chairwoman of the province People’s Committee, promised last week strong measures to improve the situation.

The local Department of Natural Resources and Environment said waste water released from the Song Than No. 1 and 2 industrial parks (IPs) into the canal has two times the allowed level of pollutants. But it did not specify what substances the waste water contains.

Le Thanh Tien, who lives on the nearby Provincial Road No. 43, said he saw huge foam bubbles in the canal and experienced the same stench there was two years ago.

Huynh Thanh Long, another resident, said the stench from the canal was strongest between 4am and 5pm every day.

Other locals also reported this to a provincial people’s council delegation that visited the area last month. The department has said that unless the IP authorities clean up the waste water, it would inspect and fine the IPs by the end of this month.

The 1.7 kilometre canal drains rainwater from 1,560 hectares of land in Binh Duong and HCM City in addition to IPs like Song Than No. 1 and 2, VN-Singapore, and Dong An, and the city’s Linh Trung processing zone.

To stop the severe pollution that was happening for many years, the department earlier this year ordered all the IPs to collect waste water and treat it before releasing into the canal.

Song Than No. 1 and 2 ostensibly obeyed though an investigation by the department in July found 11 factories in Dong An IP continuing to directly discharge effluents into the canal.

HCM City planned to join hands with Binh Duong to deal with the pollution, but a VND744 billion (USD 41.8 million) programme approved in 2007 has been delayed by site-clearance problems.

The province is dredging and cleaning the upper part of the canal, with the Binh Duong Water Supply and Drainage Ltd Co reporting that it has collected 16,000 tonnes of rubbish.

Experts said cleaning up the canal would be pointless unless authorities stop the release of polluted water from the IPs and illegal dumping of waste by trucks on Road No. 9 and in sub-canal No. 550.