Selangor police chief Hussein Omar Khan said that investigations are being carried out under Section 430 of the Penal Code for mischief by injury to works of irrigation.

“The investigations are ongoing to identify those responsible,” he said.

Hussein said samples of the substance have been collected and sent to the chemistry department for analysis.

Selangor environment department director Nor Aziah Jaafar said the eight barrels were sent to a safe disposal site in Bukit Tagar last night.

“Preliminary analysis suggests the chemical waste may be an ammonia solution,” she said.

It was reported that the fire and rescue department received information about the discovery at 9pm on Tuesday.

The department’s hazardous chemicals special team helped to clean the site and collect samples of the chemicals.

Selangor public health and environment committee chairman Jamaliah Jamaluddin said observation by the Selangor Water Management Authority found that the drain leads into Sungai Gasi and subsequently to Sungai Buloh, with no intake points from water treatment plants downstream of the area.