The impact of the fire
On Thursday 30 August 2018, a large warehouse fire broke out at 420 Somerville Road, Tottenham.
Our role as a support agency was to monitor air and water quality in the affected areas. We provided advice to the incident controller and emergency services on the scene about potential human health impacts. These included providing advice to:
- Emergency Management Victoria
- Metropolitan Fire Brigade
- Melbourne Water
- local government, including Maribyrnong City Council.
Contaminated firewater flowed into nearby Stony Creek. It contained a range of chemicals such as hydrocarbons, solvents such as acetone, herbicides and heavy metals. In the first two weeks after the fire, more than 170 cubic metres of contaminated sediment and 70 million litres of water was removed from Stony Creek by Melbourne Water.
The contamination from the firewater runoff resulted in significant loss of plant and animal life, including 2,500 dead fish in the creek and estuary. For weeks after the fire, the water quality in the creek exceeded acceptable guidelines for human health. The incident has been described as the worst pollution event to affect a Melbourne waterway.
What we did
Water and sediment sampling
Over the past year, we have visited the Stony Creek more than 20 times to sample the water and sediments, testing for a range of pollutants.
Water quality testing over the last 12 months has revealed that chemical concentrations dropped gradually, and are now below guideline values.
The major chemicals from firewater included:
- perfluorooctane sulfonate (PFOS)
- herbicide (2,4-D)
- solvents (acetone)
- hydrcarbons, by products of fire and soot
Sediment contaminants included:
- C16-C34 hydrocarbons
- C10-C40 hydrocarbons
Ambient air monitoring was conducted during the fire to measure the levels of small particles (smoke).
We also measured volatile organic compounds (VOCs) during the fire and post-fire recovery and dredging in September to April 2019.
Air quality sampling equipment (canisters and radiello passive tubes) were deployed in residential areas, where we sampled for VOCs and solvents.
- 20 cannisters over 24-hour periods to detect and measure VOCs, toxic organics and solvents.
- Two canisters during the fire.
- 18 canisters during the recovery and dredging phase.
- 20 radiello passive tubes in residential areas after the fire.
On 14 September 2018 Maribyrnong City Council became the lead agency for the Stony Creek recovery phase.
Council has worked closely with EPA and Melbourne Water. In the interests of public health and safety, the priorities were to:
- clean up the most contaminated and frequently accessed sections of Stony Creek
- prevent further contamination migrating downstream.
Initial cleanup works included:
- scraping creek banks
- pressure-washing rocks and vegetation to remove toxic sludge
- removing affected trees and shrubs
- installing in-stream barriers to capture contaminants.
To date, cleanup works have removed approximately 1,800 cubic metres of contaminated sediment over five months.
Recovery efforts are highly complex and require careful planning. This is due to the nature and extent of contamination, treatment and disposal options of contaminated sediment, and access for machinery. Cleanup works followed detailed investigations to ensure they could be done safely.
The priority at all times is to ensure the health and safety of:
- on-site operations personnel
- the community
- and the environment.