According to the National Water Services Com­mission, pollution shut down water treatment plants in rivers across Malaysia for over 1 thousand days, between 2008 and 2014. Over a third of these shutdowns occurred in Selangor.

The latest incident happened last week with the temporary closure of the The Langat and Cheras water treatment plants due to odour pollution from the Semantan River in Pahang.

We explore why the water supply disruption problem has become more prevalent in recent years, and some measures that authorities can take to reduce the impact river pollution on the state’s water security.

This is a report by Jason Lim.