Victoria’s environmental regulator has warned residents in Melbourne’s west to avoid contaminated waterways after a fire at a chemical factory sent toxic smoke billowing over the city.
Firefighters battled the blaze throughout the day and night after a large explosion at the Derrimut factory on Wednesday morning. It came after another fire at the same site resulted in the death of one person last October.
Victoria’s Environment Protection Agency (EPA) on Thursday evening said Melbourne Water was managing a “significant volume of contaminated firewater run off” which had entered Kayes Drain to the west of the site of the fire and Cherrys Main Drain, to the east.
“EPA will support Melbourne Water as it works to reduce the impact to downstream waterways including Truganina Swamp and Cherry Lake and Laverton Creek south of Dohertys Rd,” a statement said.
The EPA previously warned locals to avoid coming into contact with water in Cherry Creek, Anderson’s Swamp and Kayes Drain, in Melbourne’s west, after pollutants carried by firefighting water entered the waterways.
Stephen Landsell, the EPA’s western metropolitan region manager, on Thursday morning said the smoke’s impact was easing, as the fire was brought under control. He said Melbourne Water would install signs to alert people to the affected waterways.
The EPA would also test waterways, install sandbags and deploy trucks to suck out affected stormwater, Landsell said.
He said the EPA has inspected the factory nine times and issued two notices after the October fire.
The notices required the company to clean up and have stormwater management and prevention measures, and Landsell said the company had complied with them.
“Clearly there are big investigations to come,” he told ABC radio.
“We’ll be working really closely with WorkSafe and other regulators given there were still investigations going into the previous incident.”
“No stone will be left unturned.”
A WorkSafe spokesperson said it remained on scene to provide technical support and would “determine further action at the appropriate time.”
Guardian Australia understands WorkSafe’s investigation into last year’s fire at the same site is ongoing. It is understood that since the October fire, seven compliance notices have been issued to the factory.
On Wednesday, chemical drums were sent flying into the air at the height of the blaze, making the emergency response more dangerous for firefighters.
No one was injured and it was declared under control in about four hours, but the fire was expected to burn for days.
On Thursday morning, Fire Rescue Victoria (FRV) said nearby businesses would be allowed to return on a case-by-case basis.
FRV deputy commissioner of community safety, Joshua Fischer, said a number of chemicals and dangerous goods at the factory were consumed in the fire but the exact quantity was not known.
after newsletter promotion
The EPA has advised those nearby to avoid areas where odours remain.
The EPA had not observed any airborne ash from the fire but urged people to wash down affected surfaces and any fruit and vegetables before eating them.
The FRV deputy commissioner, Michelle Cowling, said it was the most significant blaze in Melbourne in recent years and required an aggressive response.
The nearby Western Freeway was shut for several hours and thousands of residents were urged to stay indoors due to health risks.
Cowling said there was no connection between the October blaze and the fire on Wednesday, but the cause was still under investigation.
The factory houses multiple businesses including chemical blenders and fuel distributors, with drums containing kerosene, methylated spirits, methanol and other substances stored at the site.
Prof Gabriel Da Silva, a University of Melbourne chemical engineering academic said all smoke was toxic and the biggest concern was the large amount of smoke in the area.
“The risk from the chemicals here has been largely providing that fire to happen, as opposed to people being exposed to compounds that are being released,” he said.
“Although there may be, particularly with water escaping from the site, some of these harmful compounds being carried away.”
Da Silva said in the short term, he was most concerned about those with asthma as locals were still at risk while the fire burns.