Contractor, manager charged over fatal 2024 Choa Chu Kang Waterworks toxic gas incident
The Ministry of Manpower also issued PUB the maximum composition, or out-of-court, fine of S$5,000 under the Workplace Safety and Health Act.
An aerial shot of Choa Chu Kang Waterworks. (Photo: PUB website)
This audio is generated by an AI tool.
SINGAPORE: A contractor tasked with carrying out tank cleaning operations at a PUB site was charged on Thursday (Jul 16) over alleged workplace safety lapses after two workers died in 2024.
The contractor, Stargroup, had been engaged by the national water agency for what was described as "routine" tank cleaning operations at Choa Chu Kang Waterworks.
On May 23, 2024, four workers from Stargroup and its subcontractor were cleaning a water treatment process tank.
Three of them later collapsed after entering an enclosed passage beneath the tank to close hand valves that had been opened earlier to drain water from the tank, the Ministry of Manpower (MOM) said in a press release on Thursday.
The three employees were taken to Ng Teng Fong General Hospital, where two of them died on May 24 and May 28, 2024.
The third worker was discharged after receiving medical treatment, said the ministry.
PUB said in a statement on Thursday that it takes a serious view of Stargroup's safety lapses.
“After the incident, PUB blacklisted Stargroup for 18 months from August 2024, which entailed being barred from tendering for any PUB projects during this period.”
MOM said its investigations found that the workers had been exposed to hydrogen sulphide gas, a toxic gas that is typically emitted when sludge is drained from water treatment tanks.
Hydrogen sulphide gas is colourless and can be lethal even at low concentrations.
“At the time of the incident, sensors installed at the location recorded hydrogen sulphide levels that exceeded safe thresholds, and the alarm had been triggered,” said the manpower ministry.
Stargroup was charged on Thursday for failing to implement reasonably practicable measures to minimise the risk to any person who may be affected by its undertaking at the workplace.
The authorised manager for confined space entry permits of Stargroup, Lim Beng Hock, was also charged for failing to exercise all due diligence in relation to the issuance of the permits.
OTHER ENFORCEMENT ACTIONS
MOM said it also issued a stern warning to a PUB officer for failing to cooperate with his employer to enable his employer to comply with the Workplace Safety and Health Act on the night before the incident.
PUB said that it was "reviewing the stern warning and will take the appropriate follow-up actions".
MOM also issued PUB the maximum composition, or out-of-court, fine of S$5,000 (US$3,900) under the Workplace Safety and Health Act for allowing its employees to enter the confined spaces for short periods without adequate ventilation on previous occasions.
PUB said that since the incident, it has put in place permanent ventilation for the confined space and required its plants to provide adequate ventilation for all confined spaces, even for short periods of work.
“Employers carrying out work in confined spaces are reminded that they are legally required to conduct a risk assessment before works commence, test the atmosphere within the confined space, provide workers with appropriate respiratory protective equipment, and ensure that a trained standby person is stationed outside the confined space at all times,” said MOM.
Workers also have the responsibility to comply with all confined space safety requirements, including using the required protective equipment and following safe work procedures, it added.
After the incident, MOM issued a stop-work order to PUB to cease cleaning works on pre-treatment water tanks and entry into confined spaces adjacent to these tanks.
The stop-work order was lifted on Aug 6, 2024, after PUB satisfied the stipulated conditions.
PUB said that it has enhanced its contractor management processes by confirming through checks that the measures implemented on the ground are in accordance with contractors' stated risk assessments, safe work procedures and emergency response plans.
