Was Jalan Masjid India ‘sinkhole’ natural or man-made?

 

From Chan Kok Keong

Malaysians and people all over the world were shocked and horrified by the disappearance of an Indian tourist while walking along Jalan Masjid India, Kuala Lumpur, on Aug 23.

It was a nightmare for the family of the 48-year-old woman and we sympathise with them.

As far as this so-called sinkhole is concerned, one wonders whether it has something to do with the sewage system below the road.

Most of us are familiar with the term sinkhole and its association with limestone which is commonly found in the Kinta Valley and also the Klang Valley.

The geological dictionary definition of a sinkhole is that it is a depression or hole in the ground due to collapse of the underlying soil or rock into a void caused usually by the removal of soluble rock by groundwater flow. The most common soluble rock is limestone.

Sinkholes are also the legacy of tin mining in which the removal of ore and other minerals have left voids in the ground.

Wrong use of word

The use of the term 

sinkhole

 in news reports is understandable because it resembles a sinkhole even though it may not have been caused by any underlying limestone cavity.

However, the continued use of this word is misleading as the hole may have been caused by the collapse of the sewer underneath. Up till now, no limestone has been found in its vicinity.

Indeed, three days later, on Aug 26, another hole in the ground appeared in Jalan Permai, Kampung Kerinchi, a suburb almost 6km away to the south.

On Aug 28, a second hole opened up just 50m away from the original sinkhole. It is noteworthy that the later 

sinkhole

 in Jalan Masjid India was at the same location as a 

sinkhole

 that appeared about a month earlier.

It was presumably backfilled soon after as no one had fallen into it.

No limestone

All these three sinkholes share two common features: First, they did not occur in limestone areas, and second, all are underlain by sewers.

If the Jalan Masjid India incident was not due to any underlying limestone, the Kuala Lumpur City Hall (DBKL) should direct its engineers to have a look into why the pavement suddenly collapsed instead of barking up the wrong tree by referring to the minerals and geoscience department.

No mapping done

Significantly statements have been issued like 

… Kuala Lumpur City Hall will also map the utilities and conduct a soil structural study throughout Kuala Lumpur

.

This implies that DBKL does not know where its utilities are located. Does it not keep maps of utilities constructed under its purview?

It is also apparent that the soil structure in Kuala Lumpur is not well understood despite the huge amount of development around the city.

Interference with subsoil

In Jalan Masjid India, where the road surface was disturbed by massive human intervention, ie the development of the sewage system, is it right to attribute the collapse to the 

sinkhole

 phenomenon?

Some will remember a fatal incident in Mambang Diawan, in the Kinta Valley many years ago, where a house with its occupants disappeared into a sinkhole.

There were no man-made structures surrounding that sinkhole.

Therefore, the hole in the Jalan Masjid India incident which claimed an innocent life was, in truth, not a sinkhole as understood in geological terms.

It was a hole, sad to say, which was caused by man himself. - FMT

Chan Kok Keong practises law in the Kinta Valley and is an FMT reader.

The views expressed are those of the writer and do not necessarily reflect those of MMKtT.