Sungai Tukang Batu – the most polluted river in Malaysia according to the 2017 EQR – was inaccessible, as it runs down the middle of an industrial zone which has been covered up.

Malaysiakini visited three other rivers: Sungai Buluh, considered the second most polluted river in the country based on its water quality index (WQI) number; Sungai Masai, which runs through heavily populated areas and industrial zones; as well as Sungai Kim Kim, the site of the chemical waste incident in March.

Upon first inspection, Sungai Buluh was not a welcoming sight. Surrounded by factories on both sides, its water was turbid - a murky greenish brown - and moved sluggishly due to heavy debris and sediment. A bad smell also emanated from the river, mixing with the smell of smoke from nearby factories.

Malaysiakini also witnessed wastewater being discharged from pipes running from the factories straight into the river. Whether this dumping falls within permissible standards set by authorities could not be ascertained, however.

The water was also greenish-brown at the mouth of Sungai Masai, where it pours into the Johor Straits. Several mangrove trees at the riverside had also been uprooted. Such trees serve to protect the banks from erosion, and help maintain water quality by filtering pollutants and trapping sediments from land.

At locations along Sungai Kim Kim only separated from people’s homes by several feet of small road and patches of grass, the foul smell from the highly murky river could easily be detected. Malaysiakini later also visited another part of the river which runs through an industrial area.