SHAH ALAM: Water security is the most important aspect to consider in terms of the management of the nation's water resources in view of the threat posed by the dumping of toxic wastes into rivers.
Water is a basic necessity of human beings, hence the time has come for the government to prioritise water security, which the United Nations defines as the capacity of a population to safeguard, among others, "sustainable access to adequate quantities of acceptable quality water for sustaining livelihoods, human well-being and socio-economic development".
According to water quality expert Dr Zaki Zainudin, when a nation has attained water security, there will be no interruptions in water supply and no dry taps for consumers even if contamination occurs as a result of illegal dumping of toxic chemicals into rivers.
He said although the authorities in Malaysia have taken several positive measures to reduce the incidence of pollution in rivers, which constitute a source of raw water for the nation's water supply system, the ongoing issue of interruptions in water supply has yet to be fully addressed.
Zaki blames the weak management of river basins for the persisting issue of water disruption.
"We also don't have a support plan in the event of a disruption in water supply due to the presence of pollutants in river water," he told Bernama.
Due to the vast expanse of Malaysia's river basins, it is imperative that the government formulate strategies to ensure sustainable water supply, he said.
Among the strategies that can be considered are building off-side river storage facilities, protecting water catchment areas and introducing a more sophisticated water treatment system.
OFF-SIDE RIVER STORAGE
While there is a need to have more stringent environmental laws and streamline enforcement activities, in the short term, however, water security is key to ensuring uninterrupted water supply.
Zaki, who was a member of the team that investigated the cause of pollution in Sungai Kim Kim in Pasir Gudang, Johor last year, said water security should not be the focus of just the federal and state governments but also water concessionaires.
One of the measures states could implement as part of its water security plan is the establishment of storage ponds whose water can be tapped in the event of an emergency such as water contamination.
In this respect, Zaki praised the efforts of Selangor which, through Selangor Water Management Authority (LUAS), has implemented the Hybrid Off-River Augmentation System (HORAS) to make use of abandoned mining ponds as an alternative source of raw water.
"They serve as backup ponds and if contamination occurs in the main raw water supply, water from the ponds can be used.
"The Selangor authorities used the HORAS water when contamination occurred in Sungai Semenyih late last year although it (water) was not sufficient. However, the water disruption situation in the Klang Valley would have been worse if not for the backup ponds," he added.
He also said that a proposal that was made some years ago to tap the water from Putrajaya Lake should be given due consideration as it would help to support the Sungai Semenyih water treatment plant (WTP) in the case of an emergency.
PROTECT WATER CATCHMENT AREAS
The basin of a river stretches from its upstream portions to downstream before the river water enters the estuary and empties into the sea.
It is the norm for water authorities to build the WTP at the downstream portion due to the higher quantity of water available there.
"The problem with this strategy is that over the years, the upstream areas become increasingly polluted due to rapid development and the pollutants end up flowing downstream.
"Let's take Sungai Semenyih as an example. The area where raw water is pumped into the WTP is located downstream (before it meets Sungai Langat). Hence, not surprisingly, that area is prone to pollution due to all that development that has taken place upstream," he explained.
To guarantee water security, the authorities should gazette water catchment areas as protected zones to prevent activities that can harm rivers, he stressed.
Zaki also called for the implementation of a more efficient water treatment system that allows for contaminated water to be treated directly without having to shut down the WTP as is the case now.
He said the conventional treatment used by Malaysia is also used by advanced nations such as the United States, the Netherlands and England but the system has its limitations and is only suitable for treating water that is "not too dirty".
In the United States, for instance, the conventional treatment works well because the quality of its water is relatively good as it practises sound river basin management.
"The situation is different in Malaysia due to pollution. Maybe the time has come to consider a more sophisticated treatment system such as the one used by Singapore, where sewage is treated and recycled into drinking water under its NEWater programme," he said.
CARRYING CAPACITY OF RIVERS
Zaki, who has done numerous studies on water quality, also said that rivers have the natural capacity to carry pollutants but their carrying capacity levels depend on their water volume.
If a river is endowed with a high volume of water, its carrying capacity is also high. Likewise, rivers with low water volume have low carrying capacities.
"During a drought, there's less water flowing in a river. The pollutants that are discharged into the river may be permissible under the law but it will worsen the pollution level due to the river's reduced carrying capacity," he said.
Suggesting that the relevant laws in Malaysia be reviewed to take into consideration the carrying capacities of rivers, Zaki said in the US, its laws do not only consider the concentration of pollutants in rivers but also their carrying capacities.
Currently, Malaysian rivers are categorised into five classes — I, II, III, IV and V — based on the descending order of water quality, with Class I considered good and Class V the most polluted.
However, the water quality of a river will differ from segment to segment depending on the level of pollution. For example, the downriver segments will be more polluted than the upstream portions due to the higher level of human activities.
Zaki proposed that state governments, who have jurisdiction over the rivers in their respective state, ascertain and fix the water quality of each segment of a river.
"The river must be mapped to indicate the water quality for each segment. Before approving any development project in the area, the authorities must ensure that it will not worsen the water quality in the segment concerned," he added.
According to Zaki, it is "immensely difficult" to improve the water quality of a polluted river. However, he added, steps can be taken to "maintain" the existing quality and prevent it from getting worse.
"Let's take a Class II river as an example. The authorities must make sure that in five years' time, it remains in Class II and does not get downgraded to Class III. Believe me, in five years' time, a river can get downgraded if new development projects crop up and more pollutants are discharged into the water.
"This is why I am stressing that the authorities should ascertain and fix the water quality (in various segments of the river) and ensure that the quality is maintained," he added. -- BERNAMA