HCM City (VNS/VNA) - Thequality of tap water in Ho Chi Minh City is being closely monitored byproduction and distribution units as well as independent agencies such as thecity’s Preventive Medicine Centre and district-level preventive health centres.

Test results of thecity’s water quality monitoring last year released by thecity's Preventive Medicine Centre showed that tap water samplescollected from many areas in the city failedto meet standards set by the Ministry of Health.

The centre tested more than 3,155water samples across the city last year.

Of the figure, about 1,827samples met the physical and chemical standards, and more than 3,017samples met microbiological standards. Another 1,792 samples reached chemical,physical and microbiological standards.

Meanwhile, about 2.78 percent ofsamples that the Preventive Medicine Centre took from thestate-owned Sai Gon Water Supply Corporation (Sawaco)'s facilities did not meetthe physical and chemical standards, with most samples failing to meet thechloride residual standard of between 0.3-0.5mg per litre.

The samples were also collectedfrom wells at households and tanks in districts 12, Binh Chanh, Nha Be, Can Gio,Cu Chi and Hoc Mon.

Bui Thanh Giang, deputy generaldirector of Sawaco, told Sai Gon GiaiPhong (Liberated Sai Gon) newspaper that his company only controlledwater quality at water supply stations, plants and in the pipeline system. Italso provided instructions on storage methods and usage to ensure hygienestandards.

"Storage tanks are managedby residents and authorities in localities," he said.

The company’s Water QualityManagement Department randomly takes about 100 samples of tap water a week toassess the quality of water in its water plants and water supply network.

All water samples are tested atthe department’s laboratory that meets theinternational standard ISO 17025 for quality systems in testing andcalibration.

“Basically, most test resultsbetween the preventive health centres and Sawaco are not different. If a samplefails the standards, the company will test again and quickly deal with theproblems,” Giang said.

In many cases, although the waterin plants and stations meets 100 percent of the standards, storing tap water incontainers and tanks at households or apartment buildings may not ensure waterquality if the storage is prolonged.

“Preventive medicine centres incity districts should not take tap water samples from water tanks where watersources could reflect differences in the original mix. This isto ensure test objectivity and accuracy,” Giang said.

The company said it closelycoordinated with relevant agencies to promptly detect, prevent and handlearising problems.

For example, following recentcomplaints about tap water quality from local residents in Hoc Mon district’sBa Diem commune, Sawaco immediately worked with the city's PreventiveMedicine Centre and the district’s Preventive Health Centre to test watersamples.

One sample failed to meet theiron standard of 0.5mg per litre, and another sample had alower chloride residual compared to the standard of between0.3-0.5mg per litre.

Households living at the endof the water pipeline system were rarely using water, as the water flowdid not run smoothly.

“When there is a hydraulicdisturbance at the end of the pipeline, the quality of water becomes unstable,”Giang said.

Sawaco overcame the problem byregularly flushing the water pipeline system to ensure water quality forhousehold use, he said.

The company has committed tostrictly monitor water-supply quality and implement projects to ensure that 100percent of the city’s households are provided clean, safe water.

Tran Kim Thach, head of Sawaco’sWater Quality Management Department, said the company was continuingto monitor the quality of raw water in rivers to controlpollution and salinity in the dry season, and was working with water managementunits to prevent abnormal saltwater intrusion or waste water discharge.

The department plans to regularlyconduct online monitoring of the salinity rate of surface water onthe Sai Gon and Dong Nai rivers during the dry season.

“The company will also conductstests in the laboratory to compare test results from online monitoring,especially during high tides,” he said.

When signs of increasing salinityappear, Sawaco will work with management units at Dau Tieng reservoir in TayNinh province and Tri An reservoir in Dong Nai province to discharge waterto reduce the salinity.-VNS/VNA