Stargroup and Manager Charged Over Fatal Choa Chu Kang Waterworks Incident

Charges Filed Against Stargroup and Manager

On July 16, authorities initiated legal proceedings against Stargroup, the contractor responsible for tank cleaning operations at the Choa Chu Kang Waterworks. The company faces charges for failing to implement reasonably practicable measures to minimize workplace risks. Alongside the contractor, Lim Beng Hock, the authorized manager for confined space entry permits at Stargroup, has been charged with failing to exercise due diligence regarding the issuance of those permits, according to the Ministry of Manpower (MOM) press release issued on Thursday, July 16.

The incident occurred on May 23, 2024, when four workers from Stargroup and its subcontractor were assigned to clean a water treatment process tank. Three employees entered an enclosed passage beneath the tank to close hand valves that had been opened earlier to drain water from the tank, but they collapsed shortly after. The three employees were transported to Ng Teng Fong General Hospital, where two of them died on May 24 and May 28, 2024, respectively. The third worker was discharged after receiving medical treatment.

Hydrogen Sulphide Exposure and Safety Failures

Investigations conducted by the Ministry of Manpower (MOM) identified hydrogen sulphide gas as the cause of the collapse. The ministry noted that hydrogen sulphide is a colourless, toxic gas that is typically emitted when sludge is drained from water treatment tanks and can be lethal even at low concentrations. The ministry confirmed that 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.

“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.

The ministry further stated that workers also hold the responsibility to comply with all confined space safety requirements, including using the required protective equipment and following safe work procedures.

Enforcement Actions Against PUB

The national water agency, PUB, also faced regulatory scrutiny following the accident. MOM 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. Furthermore, the ministry fined PUB for allowing its employees to enter the confined spaces for short periods without adequate ventilation on previous occasions.

Following the May 2024 incident, the ministry imposed a stop-work order to PUB to cease cleaning works on pre-treatment water tanks and entry into confined spaces adjacent to these tanks. This order remained in effect until August 6, 2024, when the agency satisfied the stipulated conditions required by the ministry. While the legal process for the contractor and its manager continues, the case highlights the ongoing regulatory focus on high-risk industrial environments in Singapore.

Contractor Licensing and Regulatory Oversight

The incident underscores the broader importance of rigorous licensing and compliance standards for mechanical and general contractors. While the Choa Chu Kang case involves specific criminal and regulatory charges, other jurisdictions maintain separate oversight bodies to manage contractor certification. For instance, the South Carolina Department of Labor, Licensing and Regulation (LLR) and the SC Contractor’s Licensing Board regulate the license, certification, or registration of general and mechanical contractors, construction managers, and other specialized trade contractors. These regulatory bodies assist with examination information, licensure applications, and renewals, such as the 2026-2028 renewal period for fire sprinkler and alarm contractors, which carries a deadline of July 31, 2026.

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