State executive councillor Hee Loy Sian said these two cases could have halted the operations of water treatment plants if the Selangor Water Management Authority (LUAS) and other agencies had not acted quickly.
He said one of the incidents involved the detection of odour pollution in Sungai Kundang, with a reading of 10 threshold odour number (TON) at 10.45am yesterday.
LUAS officers went to the area and found biodiesel materials in the river, he said.
Further investigations by LUAS and Air Selangor identified a company, operating in the Kundang Jaya industrial area, as the possible source.
LUAS issued a warning letter under Section 121(1) of the LUAS Enactment 1999 to the company to immediately halt effluent discharge and carry out cleaning activities.
He said LUAS used 300kg of activated carbon to contain the odour pollution. Samples were also taken from three locations along the river and sent to the Chemistry Department for analysis and further action.
Hee said the other incident involved a diesel oil spill in Tasik Putrajaya at about 9.35am yesterday, after a skid tank pipe burst underneath the National Cancer Institute (NCI).
The NCI immediately conducted cleaning work with the assistance of LUAS, Putrajaya Corporation (PPJ) and other agencies to avoid further damage.
He said the NCI had also installed oil pads and oil containment booms along its drainage systems to clean up the spill.
The diesel could have polluted Sungai Langat and caused the water treatment plant 10km away at Bukit Tampoi to halt operations, he said, adding that LUAS is monitoring the situation.
“These two incidents were successfully dealt with immediately by LUAS, Air Selangor, PPJ and other agencies.
“The water treatment plants carried on operating and there was no water supply disruption to consumers.”
Earlier this week, odour pollution in Sungai Selangor forced four water treatment plants to shut down, affecting almost 1,300 areas in the Klang Valley and disrupting supply to 1.2 million households.
Police have opened an investigation paper into the incident, with LUAS and the Department of Environment assisting in the investigation. Water samples have also been sent for analysis to determine the cause of the pollution.
Police have remanded eight people, including a director of a company repairing and selling construction machinery in Rawang, over the pollution.