PETALING JAYA: This is why over eight million people in the Klang Valley will continue to suffer from water cuts.
Unbridled development along the banks and in the basin of Sungai Selangor and Sungai Langat and their tributaries is exposing the river to pollution and also reducing the rivers’ carrying capacity to dilute or absorb any pollutant or effluent, or what is known as the Total Maximum Daily Load.
“Yes, the load changes and has been used up, ” said water quality expert Dr Zaki Zainudin.
“As you have more and more development, and more and more pollution, bit by bit, the capacity is taken up, ” he said.
The fact that the rivers can no longer absorb effluents as effectively, said Dr Zaki, was definitely a contributing factor to the pollution incidents that continue to shut down treatment plants along Sungai Selangor.
This is Sungai Selangor (or rather a 30km stretch of the main Sungai Selangor from Bestari Jaya to Sungai Tinggi and then to Ulu Yam).
The Sungai Selangor river basin, which covers an area of 2,200 sq km and has 10 sub-basins, supplies some 60% of the water in the state, as well as Putrajaya and Kuala Lumpur.
Sungai Langat and its tributary Sungai Semenyih provide the other 30% of the water supply in the Klang Valley.
However, as the video shows, there are various socioeconomic activities along the river, ranging from industries such as aquaculture farms, sand mining and land clearing, to residential homes.
Looking at the video, Global Environment Centre (GEC) river care programme coordinator Dr K. Kalithasan said the Sungai Selangor basin looks like mainly a huge industrial area.
"We can see from the recent Sungai Gong case what the effluents from industries can lead to.
"Another thing, we can see massive agricultural activities, which can introduce a lot of chemical fertiliser and pesticide, and the wastewater can have significant effects. We need to realise that it is very difficult to remove inorganic pollutants from the water body.
“There is also a lot of the usual land-clearing activities," he said.
While many of these socioeconomic activities are legal - the Selangor state executive councillor for the environment Hee Loy Sian told reporters on Oct 19 that there were no illegal factories along the river - this certainly make stretches of the river vulnerable to sources of pollution or worse, the illegal dumping of waste.
Some of the development is located only metres away from the bank of the river, and some even go right up to the edge.
This is despite existing guidelines from the Drainage and Irrigation Department that require any activity or development to be located at least between 5m and 50m from the bank depending on the width of the waterway.
The definition of a "river reserve" is itself provided for under Section 62 of the National Land Act.
Two recent instances of odour pollution in one of Sungai Selangor's tributaries, Sg Gong, had led to a water supply disruption affecting over one million account holders in the Klang Valley in the three months since September.
Four water treatment plants - Sg Selangor Phase 1,2, 3 and Rantau Panjang - had to be closed down.
In both cases, the solvents in Sg Gong, which channels into Sungai Sembah before joining up with Sungai Selangor, were eventually traced to nearby car parts and machinery factories.
When The Star visited one of the factories - where authorities alleged that between Sept 2 and 3, a solvent was poured into a drain that leads into Sungai Gong, a tributary of Sungai Sembah which eventually joins up to Sungai Selangor -- it was vacant and according to the Selangor Mentri Besar then, would be closed down permanently.
A worker at a nursery beside the factory, who declined to be named, does not believe that the pollution of Sungai Gong is due to only one factory as there are many factories operating in the area.
“All the factories in Rawang have a drain connecting directly into Sungai Gong, ” he said.
The distance between the factory and Sungai Gong is about 5km with a drain connecting the two. The factory had reportedly been issued a notice earlier for building structures without approval from the Selayang Municipal Council.
Back in 2015, then Lembaga Urus Air Selangor (LUAS) director Md Khairi Selamat had told The Star that based on its inspections, the place with the most potential for pollution was Sungai Sembah near Rawang, which had an increasing number of residential and industrial areas.
LUAS is Selangor's foremost water authority.
The situation with Sungai Langat and Semenyih is not any better and could, in actual fact, be worse.
"We have talked a lot about Sungai Selangor but for me, Sungai Langat equally is important because there is a lot of high-risk activities there. We’re just waiting for an incident to happen, if no mitigation efforts are taken," said Dr Kalithasan.
He said from what he noticed in the video above, there were four key activities that could have a significant impact on raw water for Sungai Langat.
"Number one is aquaculture or fish ponds, which can lead to an accumulation of ammoniacal nitrogen, as well as chemicals if they are being used.
"It can also cause oxygen depletion. We also see that there are massive land clearing activities, either for industrial or housing areas.
"In fact, there is a huge housing area near Bangi. The issue is whether there are proper mitigation measures being taken, like silt traps, which could prevent Total Suspended Solids, that is one of the parameters in the Water Quality Index (WQI)," he said.
Dr Kalithasan said when there were land clearing for housing areas, it was not just about turbidity (a measure of how clear or cloudy a water sample is) or erosion.
"Sometimes, the use of heavy vehicles can lead to oil leakage. Land clearing activities could cause erosion and cause water to be turbid, and the use of heavy vehicles, if left unchecked, could cause an issue like what happened in Sungai Selangor recently," he said.
The other issue in Sungai Langat is the industrial area.
"We see that it is one of the key issues where people are not serious about managing their effluence. Sometimes, the waste is not audited and the scheduled waste is disposed of carelessly.
"This could affect the Chemical Oxygen Demand (COD), which is one of the parameters of the WQI," said Dr Kalithasan.
He said similarly, there was a lot of land clearing activities around Sungai Semenyih.
"We can also see that there are many housing areas near there. And, if I’m not mistaken, there are also some records which show that previously there were some environmental issues with the industries in that area," he said.
Dr Kalithasan said these were all the major activities that posed a significant risk to Selangor's water sources, adding that there was a need to explain to consumers what water intake actually involved.
"They still perceive that the raw water from the water treatment plant comes from the dam, which is not always true. That’s why people don’t see taking care of the rivers as important, and they don’t see how significant rivers are as a water supply.
“They still believe that each river has a dam or reservoir and they think that all water comes from there, so they do not need to worry about the water that flows near their area. The water is actually directly extracted from the river in their area.
"For example, in Cheras, they get their water from Sungai Langat in Bangi - how many kilometres are between the two places, how many tributaries and monsoon drain discharge points and how many industrial areas the river water would have had to pass through?" Dr Kalithasan pointed out.
The public, he added, need to be educated on why they have to put in the effort to monitor rivers because this would affect them - not just in terms of water quality but quantity as well.
"People need to know their ‘river addresses’: the name of the river that flows through their area, where their drinking water comes from (which waste treatment plant) and where our sewage water ends up (the waste treatment plant).
"It’s much easier to prevent pollution than to treat it," he said.
In an interview with Star Metro on Aug 21, the Selangor state executive councillor charge of public infrastructure and facility, agricultural modernisation and agro-based industry, Izham Hashim, said the state was in the midst of crafting "Zero Discharge" and "Polluters Pay" policies.
The “Zero Discharge” policy would compel industries to recycle effluents instead of releasing them into the drainage system, while under the “Polluters Pay” policy, those who discharge effluents into the river will have to pay for any additional amount discharged beyond the regulated, acceptable volume.
Izham also said LUAS was in the midst of studying the implementation of Total Maximum Daily Load (TMDL).
Dr Zaki said while incidents like the Sg Gong pollution were usually ad hoc, TMDL involves a river's carrying capacity to withstand the regulated discharge of effluents allowed by the authorities.
"We must set water quality and TMDL targets," he said during a webinar organised by the Drainage and Irrigation Department in conjunction with National Environment Day on Oct 21.
He also urged the authorities to have risk mitigation by coming up with a list of high risk/ incompatible industries allowed to operate in upstream areas of a water intake point.
He cited as an example booming development activities in another state that could also ultimately impact the quality of water in Selangor's rivers.
Sungai Selangor originates from Fraser's Hill in Pahang while Sg Langat stems from the Titiwangsa Mountain Range along the state's border in Pahang.
Dr Zaki also urged the setting up of pollution detection stations that could quickly detect pollution and deploy an investigating team.
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