Wetting rubbish in chutes: New system to prevent rubbish chute fires on trial

Plan to discharge water on rubbish so it won't ignite easily
By Janice Tai, The Straits Times, 11 Nov 2014

REFUSE chutes at 20 HDB blocks all over the island will periodically squirt water on rubbish in a one-year pilot project to prevent it from catching fire.

The idea is to wet the refuse collected within the chutes by discharging water at pre-determined timings so that it will not be easily ignited by, for example, a cigarette butt thrown into the chute.

The Singapore Civil Defence Force (SCDF), National Fire and Civil Emergency Preparedness Council, and the HDB will install the Timer-based Water Release System at the 20 blocks of flats islandwide - 10 built before 1990 and 10 newer ones - next year.

The SCDF declined to give details on how often the water will be discharged, saying that this will be calibrated during the trial to ensure prudent use of water.

Rubbish chute fire is the most common type of residential fire and has been occurring more frequently. In the first half of this year, 819 fires occurred in rubbish chutes and bins, compared to 680 the year before.

It formed more than half of the 1,493 fires that happened in residential premises, SCDF statistics showed.

"The installation of the system would serve as a pre-emptive measure to reduce the occurrence of such refuse chute fires," said a spokesman for the SCDF.

"While they generally do not pose a major fire risk, the resulting smoke inconveniences the residents.

"It also drains the SCDF fire-fighting resources in attending to more than a thousand of such minor fire incidents annually," he said.

In all HDB blocks, the flushing system used to clean the chute can double up as a water-sprinkler if a fire occurs.

But this can be activated only by rubbish collection workers at the ground floor.

Each HDB block constructed from 1990 has a central refuse chute which ends in a bin centre.

The bin centre is fitted with heat detectors that can trigger the flushing system, but these sensors detect only fire in the bin centre, and not directly within the chute.

Previously, the SCDF, the council and the HDB carried out two trials to address the problem of chute fires, but both methods that were tested had drawbacks.

In 2006, automatic sprinklers were installed within some rubbish chutes in some older blocks in Jurong West, but installation costs were high and the moist environment within the chutes corroded the heat detectors over time, rendering them ineffective.

In 2011, buttons to activate the chute flushing system were installed in the common areas of some blocks in Tanjong Pagar GRC, so residents could press them to release water down the chute if a fire broke out.

However, this led to a number of false alarms and the buttons were pressed when there were no rubbish chute fires, resulting in water wastage, said the SCDF.

It added that more rubbish chute fires tend to occur during the festive season - about half of the 819 cases from the first half of this year happened in January and February due to indiscriminate disposal of lighted materials such as sparklers, charcoal and incense materials.

The SCDF has been visiting clusters of flats that show high incidences of rubbish chute fires to remind residents to refrain from throwing lighted cigarettes, charcoal with embers or flammable substances such as oil and paint into the rubbish chutes.

Retiree David Kwok, 63, said: "The new system is good because it is proactive and doesn't wait for fires to start or smoke to appear before being activated. But the downside is that it may waste water, and rubbish that is wet can be heavy for the workers when they clear it."

Problems with wetting rubbish in chutes

ARE we moving backwards by squirting water into our rubbish chutes to prevent fires ("New system to prevent rubbish chute fires on trial"; Tuesday)?

Residents have been taught to bag their rubbish before throwing it into the chutes. Thus, the area around rubbish chute doors is drier and less smelly, especially for those living on lower storeys.

Wetting the rubbish in chutes could encourage bacteria and insect growth, as well as promote mosquito and cockroach breeding.

Filthy water seeping out of the rubbish chute doors would also stink up the place and attract houseflies.

Lastly, residents may revert to the practice of throwing rubbish directly into the chutes, since there is no longer a need to keep the chutes dry.

The fire hazard should be dealt with at the source, by ensuring people dispose of their cigarette butts in a responsible manner.

Many readers have written in to complain about second-hand smoke from neighbours and cigarette ashes flying into their homes.

Can the authorities look into this problem instead of implementing solutions that seem to condone irresponsible smoking habits?

Chee Chi Weng
ST Forum, 15 Nov 2014

Wetting rubbish in chutes: Measures to address concerns

WE THANK Mr Chee Chi Weng for his feedback ("Problems with wetting rubbish in chutes"; Nov 15).

Refuse-chute fire forms the largest component of residential fires in Singapore. While such an incident does not generally pose a major fire risk, the resulting smoke inconveniences residents. It also drains the Singapore Civil Defence Force (SCDF) fire-fighting resources in attending to more than a thousand of such minor fire incidents annually.

In the light of this, the National Fire and Civil Emergency Preparedness Council (NFEC) and SCDF, in consultation with the HDB, are embarking on a timer-based water release system (TWRS) trial to address refuse-chute fires.

The TWRS is a pre-emptive measure to reduce refuse-chute fires by discharging spurts of water into the chutes at pre-determined timings each day to dampen the surface of the refuse. This serves to prevent the refuse from being easily ignited by a heat source such as charcoal embers, lighted cigarette butts, sparklers or incense materials that are indiscriminately thrown into the chutes.

We share Mr Chee's concerns on bacteria growth and breeding of pests, and assure him that all refuse chutes are designed with drainage to prevent the accumulation of stagnant water.

For the TWRS, the amount of water released will be calibrated to ensure prudent and minimal usage, while achieving the optimal result of reducing refuse-chute fires.

The SCDF is also consulting the National Environment Agency on the environmental public health and waste disposal concerns.

Mr Chee rightly pointed out that it is important to address social behaviours that contribute to fire hazards. Apart from exploring pre-emptive measures such as the TWRS to reduce fire occurrences, the NFEC and SCDF have, over the years, worked closely with community partners and grassroots leaders to instil fire safety consciousness. Fire safety tips to prevent common causes of residential fires, including refuse-chute fires, are shared with the public through various platforms such as the Community Emergency Preparedness Programme, Emergency Preparedness Day events, SCDF Emergency Handbook and website.

We remind everyone to continue to be fire safety-conscious in ensuring a pleasant and safe living environment.

Leslie Williams (Lieutenant-Colonel)
Assistant Director (Public Affairs Department)
Singapore Civil Defence Force
ST Forum, 26 Nov 2014

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