Levels of E. coli in 90 per cent of Hong Kong river monitoring stations ‘didn’t meet quality goals’
Audit Commission criticised authorities over delays in enforcement of village sewer programme and lax oversight on private septic tank systems
Levels of E. coli at nearly 90 per cent of the city’s river monitoring stations exceeded corresponding water quality objectives last year, suggesting authorities needed to rapidly step up pollution control in unsewered rural areas, the government auditor has warned.
In a report, the Audit Commission criticised environmental and drainage officials over slow implementation of village sewer programmes and lax oversight on private septic tank systems.
It stressed more than 510,000 people – mostly residents of village houses, squatters and those in private housing across the New Territories – were still not connected to public sewerage facilities and at least 70,000 village houses were relying on mostly unlicensed septic tank systems to treat their waste water.
About 84,000 squatter homes were still discharging sewage, untreated or filtered through basic flow interceptors, into nearby rivers or water bodies.
Meanwhile, only a quarter of a village sewage programme, rolled out in 2001 and which covered 662 villages, was completed as of June this year. It was originally targeted for completion between 2004 and 2009. “The long delays in completing the programmes are undesirable [as they] would defer improvements to village sewerage in rural areas and perpetuate the hygiene and environment problems caused by the less than satisfactory sewerage systems in these areas,” the report read.
The Environmental Protection Department (EPD) bore the brunt of the criticism, as the auditor slammed it for not conducting periodic assessments on the extent of pollution in major rivers due to sewage discharge.
An audit examination of the department’s 71 river monitoring stations in water control subzones revealed average levels of E. coli at 63 had exceeded last year’s corresponding statutory water quality objectives. A higher E. coli count indicates faecal contamination.
It also found there was a lack of effective ways to prevent septic tank systems from causing pollution, with only 1,912 of the 154,000 village and squatter homes having a licence. There was also no licensing system to hold companies that carry out private disposal of septic sludge accountable.
Baptist University assistant professor of biology Jill Chiu Man-ying said septic tanks could not remove nutrients such as nitrogen from waste water, and when such water is discharged into marine environments, it could lead to algal blooms. She agreed there was a need for tighter regulation.
“Audit recommended that [the EPD] consider periodically conducting assessments of the extent of pollution of major rivers caused by village sewage discharge, and publishing the results,” the auditor said.
It also urged the departments to explore ways to beef up control over septic tank systems and ensure houses were linked to public sewers within a reasonable time. The departments agreed with the recommendations.