Everything About the Choa Chu Kang Waterworks Incident, Which Led to 1 Death & 2 in ICU

Earlier in May, a few clips went viral on Telegram and Facebook showing a condominium basement flooded up to the knee. Thankfully, nobody got hurt.

Other than stress over some soaked cars, residents were wading around and some dogs took the opportunity to play fetch and swim in the flood.

This time, however, the situation wasn’t so amusing.

Three PUB sub-contractors were tasked to clean out the tanks at Choa Chu Kang Waterworks. One of them ended up tragically passing, while the other two workers were admitted to the ICU.

What Happened?

Singapore’s Water Agency, PUB, informed news outlets in a statement on Thursday (23 May) that three sub-contractor workers collapsed after being tasked to do a routine cleaning of the water tanks at Choa Chu Kang Waterworks.

The incident occurred at the site at around 11.15 am, said PUB.

PUB said that based on their initial investigations, the workers may have collapsed due to inhaling hydrogen sulphide.

The hydrogen sulphide was produced from the sludge in the water tank, a by-product of the treatment process.

Two Workers in ICU While One Worker Died

PUB also said that all three workers were taken to Ng Teng Fong Hospital while they were still unconscious.

Choa Chu Kang Waterworks is located at Nanyang Drive, and it is the second largest waterworks in Singapore. It was last upgraded in 2019.

Ng Teng Fong Hospital is a 20-minute drive from the Waterworks.

PUB said that the worker died while at the hospital. The two unconscious workers are still in the ICU.

The Singapore Civil Defence Force (SCDF) said that they performed CPR on one of the workers on the way to the hospital.

A spokesperson for the Ministry of Manpower (MOM) told CNA that the man who died was 40 years old from India. He was a cleaning operations manager for Supersonic Maintenance Services.

The two other workers in the ICU are Malaysians aged 39 and 24, and they are general workers for Supersonic Maintenance Services and Stargroup Est. respectively.

Inhaled Toxic Gas, PUB Implements Safety Timeout

Remember the haze? Whenever the air quality plummets, clinics and hospitals everywhere receive an influx of patients because people find it hard to breathe.

A similar thing happened at the site. The man inhaled hydrogen sulphide (H₂S). It’s colourless, which means you can’t see it until it’s too late.

It apparently smells like rotten eggs and it can irritate your eyes and your respiratory system.

Inhale it long enough and you may go into a coma, and experience convulsions, dizziness, headache and upset stomach, according to the US Centre for Disease Control and Prevention.

The US Department of Labour says that the H₂S gas is extremely flammable and toxic. It naturally appears in sewers, water wells and volcanoes.

The SCDF told CNA that they had firefighters and hazmat specialists be in personal protective equipment while on site. They used two water jets to disperse the toxic gas. That took an hour.

Because of that, MOM suggested better ventilation to ensure that the toxic gases in the tanks don’t accumulate.

In other words, prevent a toxic smoke bomb at work.

They also said that workers need to have gas monitoring devices and personal protective equipment.

Meanwhile, PUB said that it has called for a safety time-out for similar cleaning operations in other confined sites until they review the safety measures in place.

They said that the safety and health of workers are of utmost importance to PUB and they plan to fully cooperate with the investigation. They expressed condolences to the family of the worker who passed and they want to provide support to affected families.