By Ir. Balachandran Naicker, Subang Jaya
The pollution of our raw water supply has resulted in numerous disruptions to our daily lives. When our water supply is disrupted, we land up relying on our reserves at home; water tankers bringing supplies or buying bottled water for use. In this report, we explore the possibility of harnessing ground water as the backup plan.
(This paper is NOT an academic treatise on the solution but focused on some pragmatic solutions to this problem. Emphasis has been placed on solutions that can be implemented within a short timeframe and at a reasonable cost)
Residents of the state of Selangor (and the Klang Valley in general) are probably scrambling to look at possible measures to take to help mitigate the effects of another water supply outage caused by pollution of the raw water supply to Pertubuhan Air Selangor Berhad’s (or AIS’s for short) Water Treatment Plants (or WTPs)!
These notice of supply disruptions caused by pollution is always in the very last minute and consumers never have enough time to take the requisite urgent measures to try to store enough water to tide them over until supply resumes.
How much water can one store when supply pressure begins dwindling from the moment the announcement of the outage is made?
Many have resorted to installing additional storage tanks to their homes in the hope that the additional storage capacity will help them tide over the supply outage. Many other consumers who cannot afford these additional storage tanks are left to cope with the meagre supply from the AIS’s mobile tankers – tankers which are usually mobilised long after the supply dries up!
Let us first take a quick look at the various water supply outages, especially the durations and the number of consumers affected (where data is available) from 2019 onwards:-
As one can see from the list above, most of the causes for the water supply outages seemed to have stemmed from pollution upstream of the raw water intakes.
From the figure above, the raw water management (monitoring and enforcement) falls under the jurisdiction of LUAS and Jabatan Alam Sekitar (or JAS for short) (Department of Environment).
An important consideration in the decision to site any raw water intake for public water supply is the assurance that there are no sources of pollution UPSTREAM of the intake.
Was this consideration taken into account in the development of Selangor’s Water Treatment Plants? If not, then why not?
Some recommendations to help alleviate/eliminate the risk of pollution will include:-
- The demarking of the entire catchment areas of the WTPs;
- Survey of all occupiers of land within the catchment areas;
- Evict ALL illegal occupiers;
- Developing a classification of the legal occupiers of land within the catchment from NO RISK to HIGH RISK polluters;
- The gazettement of the catchment areas with a restriction on pollution causing activities;
- Notice to all HIGH RISK occupiers to move out of catchment area or the mandatory acquisition of land belonging to HIGH RISK occupiers. This may be expensive but necessary.
ADUN for Subang Jaya Michelle Ng, the sitting Chairman of the Selangor State Government Select Committee on Raw Water Resources, had, in the recent sitting of the Selangor State Assembly, tabled a slew of enactments which provides for punitive punishment for polluters. These new enactments will help discourage the, what seems to be, rampant pollution of the precious water resources.
But the efficacy of these new enactments is very dependent on the monitoring/enforcement of the legislations by Lembaga Air Negeri Selangor or LUAS (the Selangor Water Resources Management Board) and the Federal Government agency Jabatan Alam Sekitar (or JAS)
Is LUAS/JAS up to it? Only time will tell. And in the meantime, pollution incidents at these sensitive locations will continue and Selangor residents will continue to suffer!
So what do can we do?
The solution may lie in the management of the SPARE CAPACITY of AIS. Basically, SPARE CAPACITY is the quantity of potable water that can be distributed to consumers in the event a WTP shuts down for whatever reason – thus ensuring an uninterrupted water supply to end users.
Currently the SPARE CAPACITY has been quoted by various sources as being 0% to about 5% -which is too low! There was a recent statement by AIS that they are targeting a SPARE CAPACITY of 15 to 20%. Is this enough? Let us not forget that the Non-Revenue Water or NRW statistic for the AIS managed system is still at close to 35% to 40%. The NRW is a broad indicator of what volume of the treated water is wasted in leakages and theft.
To address the problem, the State Government will need to determine what is the target SPARE CAPACITY and how the state is going to implement this increase.
Based on the past practices of the State Government, these attempts at harnessing surface water resources for public water supply to provide this all-important SPARE CAPACITY is going to be very expensive and time consuming to implement.
So do we continue to suffer whilst these SPARE CAPACITY enhancement projects are planned and implemented?
No, NOT if the efforts made to increase the standby SPARE CAPACITY is based on an under utilised raw water resource – GROUNDWATER!
(Note: Standby SPARE CAPACITY is the making available of an alternate water source to cover an emergency shutdown of any WTP. In other words, this is only turned on when there is an emergency and turned off soon afterwards)
The State Government has been wrestling with the issue of meeting the urgent requirement of an increased SPARE CAPACITY for a long while. A result of these demands, HORAS 600 (or Hybrid Off River Augmentation System 600) alternate raw water supply system was declared open on 27th November 2019 (the project implementation started in July 2015).
The Dato Menteri Besar of Selangor declared that with the coming onstream of the HORAS 600, water outages will be a rare occurrence is Selangor.
Sadly, as events turned out, that was NOT to be the case!
So why are the planners NOT looking at groundwater as a resource to increase SPARE CAPACITY?
LUAS already manages all groundwater extractions. LUAS charges RM150/annum licence and RM0.01/cubic metre of water extracted measured via a water meter installed at the outlet of the groundwater borewell.
How do we use groundwater to significantly increase the standby SPARE CAPACITY?
The diagram below is a sketch on a proposal of how this standby SPARE CAPACITY (or Supplemental Water Supply system) can be implemented within a very short timeframe in Selangor.
The option to adopt (which may be a combination of options 1 and 2) would be the subject of an URGENT Study which needs to ascertain:-
- The prospect of the viable extraction of good quality groundwater of sufficient quantity to meet the supply requirements of a specific WTP;
- If item 1 cannot be met, then Option 1 will need to meld with Option 2 to meet the supply requirements;
- A 3rd option could be an more distributed system involving the siting of borewell farms to be managed jointly by the PBT and AIS. This option will need to be a fallback option when the melding of Options 1 and 2 still does not meet the requirements of this standby SPARE CAPACITY.
Immediate Requirements:
- Recognise that an immediate solution to the standby SPARE CAPACITY will need to be addressed;
- Form a TASKFORCE made of experts in the industry to determine how best to implement this in the shortest timeframe possible;
- Identify specific WTPs as a TEST SITE. (This step may not be necessary if the Taskforce decides that the volume of the standby SPARE CAPACITY availability needs to be met urgently);
- Ensure public education on the safety of the use of properly surveyed and secured groundwater from borewells to be used as the standby SPARE CAPACITY during WTP outages
