KUALA LUMPUR: The onus is on state governments to stop allowing high-risk premises from operating upstream from water treatment plants in order to minimise contamination risk for raw water.
Water quality specialist Dr Zaki Zainudin said state governments must begin by targeting new industries in order to prioritise raw water sources and protect the catchment areas.
"We can also opt to monitor the hundreds of outfits and beef up enforcement. However, it's extremely difficult to keep watch round-the-clock and identify who is dumping waste or unregulated effluents, legal or otherwise, as the stretches are extensive."
Zaki was commenting on the recent contamination issue which led to the shutdown of the Sungai Semenyih and the Bukit Tampoi water treatment plants on Sunday.
The closure of the plants affected water supply for more than 300,000 account holders in the Klang Valley. It was also the second major supply disruption for Klang Valley folk in a little over a month.
Zaki, meanwhile, said that in this case, the fact that the source of the pollutants was traced to 30km away from the nearest treatment plant was testament to this.
He also noted that the extensive basin of the pollution-prone Sungai Semenyih was also littered with numerous industrial and agricultural industries.
Experts have long deemed the river problematic because of this.
Such pollution had also consistently led to the shutdown of the Sungai Semenyih Water Treatment plant over the years.
Zaki said the wiser way to prevent the pollution was to have the states enforce a ban on new high- risk establishments.
He said "high-risk" should be determined by experts by weighing the category of effluents, their quantities and type of operations.
Zaki also said the ban should cover the expansion of facilities that were already up and running in the upstream areas.
"This entire exercise should be done to eventually phase out all factories and establishments from operating upstream from water treatment plants.
"It requires political will and takes time, but in the interest of maintaining a sustainable supply of water which is safe for drinking, this should be done."
Zaki said the state's proposal to channel water from Putrajaya was only a contingency measure and was unsustainable in the long run.
He feared that depending on engineering feats such as the Langat 2 water treatment plant for a back-up was unsustainable and not practical in the long term as most river basins in the country are beset with the same problem.
Association of Water and Energy Research Malaysia president S. Piarapakaran said amendments to the Environmental Quality Act 1974 should include a clause to channel the compounds and court fines fully back to ratepayers via rebates in their water bills.
He said this, together with the Water Services Industry Act 2006, would give the government more muscle to prevent repeat incidents.