Malaysia: Murky Sungai Selangor may affect drinking water of 3 million in Klang Valley

Heavy rainfall, high turbidity
The Star 7 Dec 11;

SHAH ALAM: The high-level of turbidity in Sungai Selangor is due to the heavy rainfall experienced over the weekend, state Irrigation and Drainage (DID) department director Mohd Abdul Nassir Bidin said.

He said this phenomenon was normal and the river would clear up once the weather improved.

“There was no sign of a point source which contributed to the murkiness, such as illegal logging, factories discharging waste to the river or a dumping site.

“The high turbidity is normal when there is heavy rainfall in a tropical region like ours.

“The rainwater will flow into the river and the sediment load is quite high,” he told The Star.

He said the oil palm estates and vegetable plantations lining the middle and lower section of Sungai Selangor had also contributed to the murkiness.

However, he said there was no need to be alarmed as this was a natural phenomenon.

On Monday, Syabas warned that some three million people in the Klang Valley may expect water cuts due to the sudden turbidity of Sungai Selangor water plants in Ijok.

The murky waters had caused production to drop by 60% at the four plants, said Syabas.

As a result, extraordinary turbidity of over 6,000 NTU (Ne­­phelometric Turbidity Units) in the morning was recorded compared to 300 NTU on normal days

Meanwhile, the turbidity at Kuala Badong on Sungai Selangor was at 399 NTU as of 5pm yesterday.

DID deputy director Norhisham Mohd Ghazali said the figure was slightly elevated but it could not be considered high unless the mean figure had been derived over a period of time.

The greater the amount of total suspended solids in the water, the murkier the water would appear and the higher the measured turbidity.

The World Health Organisation recommended that the turbidity of drinking water be not more than 5 NTU, and should ideally be below 1 NTU.

'Riverbank collapse caused turbidity'
G. Surach and Predeep Nambiar New Straits Times 8 Dec 11;

THE turbidity in the waters of Sungai Selangor was caused by the collapse of an embankment along its tributary, Sungai Kerling.

Selangor Menteri Besar Tan Sri Abdul Khalid Ibrahim, in revealing this yesterday, said Lembaga Urus Air Selangor (Luas) detected the embankment failure which occurred about 2km from the Sungai Kerling mini hydro-power station.

It was located close to the Selangor-Pahang border.

"According to the report I received from Luas, the collapse (embankment) along the Sungai Kerling was due to natural causes.

"There were no sign that any manmade activities, such as logging and sand-mining, was the cause of the collapse.

"It had been raining heavily and the riverbank gave way," he said after chairing the weekly state executive council meeting, here.

He said Luas would continue to monitor the situation while preparing contingency plans on the matter.

Khalid said Luas had suggested that additional ponds be built to allow water from Sungai Selangor to flow in, from where the water would, in turn, flow into four water treatment plants.

The move would allow for the reduction of turbidity in the water and also ensure undisrupted water flow.

Khalid, however, said the state would only finalise the move once Luas had come up with the full details of the proposal.

Earlier, in Puchong, Khalid had urged the public not to worry unduly over the murky water in Sungai Selangor.

He said the condition of the water posed no threat as the treatment plants were fully capable of filtering out the turbidity and delivering clean water to the public.

Khalid said this after handing over the Air Hitam sanitary landfill in Air Hitam to the Subang Jaya Municipal Council.

Khalid said water concessionaire Syarikat Bekalan Air Selangor Sdn Bhd (Syabas) was capable of handling similar problems at all its water treatment plants in the state.

Syabas' head of corporate affairs Halem Mat Som said that he welcomed the state government's decision to hire an independent regulator and an operations auditor from the international consultancy firm, Halcrow, to look into the cause of the pollution in Sungai Selangor.

"We certainly welcome the call to clarify the cause of the turbidity and the slow production of clean water and hope the move will result in a continuous flow of water to the people of Klang Valley," Halem said.

Syabas had, on Monday, warned that more than three million people in the Klang Valley risked water cuts because of the turbid water, which had affected the water treatment plants in Ijok.

This had resulted in a drop of 60 per cent in clean water production.