Every effort must be made to ensure water is safe

PUBLISHED : Monday, 12 April, 2004, 12:00am
UPDATED : Monday, 12 April, 2004, 12:00am

Hong Kong residents have heard much about the cost of importing most of the city's water supplies from the Dongjiang, or East River, in Guangdong. Less often mentioned are questions about the quality of the water and the rising levels of pollution in the region surrounding the river.

Over the years, the Water Supplies Department has expressed some concern over contamination from agricultural runoff, untreated sewage and industrial waste, but it maintains that contamination is within acceptable boundaries. It has consistently claimed that Guangdong's multibillion-dollar Dongjiang aqueduct, built with the help of an interest-free loan from Hong Kong, will solve any remaining problems. But the findings of Greenpeace, released last week, contradict these assertions. At the very least, they deserve some discussion, if not follow-up studies by the department.

Greenpeace tested Dongjiang water at several points and found high concentrations of the E coli bacteria and mercury. There are two caveats about these findings: the water being tested has not been treated, and the study was conducted during the dry season, when water levels are low and pollutants are less diluted. Tests on treated water found downstream or piped into Hong Kong might have more acceptable levels, and other seasons might produce different results.

But the readings - with E coli at 91 to 1,000 times the national limit - are a cause for concern. Downstream treatment has its limits. Chlorine, for instance, can kill E coli but extremely high levels of chlorine could be unsafe. It might be more efficient, not to mention more cost-effective, to reduce and treat the pollution at its source. This is something Greenpeace has long been arguing for, and if its findings are correct, there is reason to study the need for these measures. The group's suggestion that funds be diverted from the aqueduct project, however, are unrealistic considering the project has already begun operating.

Another issue of contention is whether the highly polluted Sima tributary is contributing to contamination in the Dongjiang aqueduct. Both sides of the argument have minimal evidence to back their claims. Considering how important the safety of the Dongjiang water supply is for at least 17 million residents in the region, a follow-up study should be conducted. This study should be a cross-border effort, laying more groundwork for a regional approach to water resources management that has long been talked about but hardly achieved.

The recent findings are based on a small number of samples and are not definitive. But they do raise some serious questions that should not be dismissed out of hand. The Hong Kong government has expended a commendable amount of effort negotiating a fairer price for the water bought from Guangdong. It should be working just as hard to see that it is safe.