Tuesday 24 September 2019
EPA is working closely with Maribyrnong City Council and Melbourne Water to restore Stony Creek and the surrounding environment as quickly as possible.
EPA continues to monitor the environment in the affected areas and provide advice around the potential human health and environmental impacts.
The blue line shows the local waterway Stony Creek.
The current advice is:
- The remediation work being conducted by Melbourne Water has removed most of the black sludge and contaminated water in or on the edge of the creek. But if you come into contact with contaminated water or sludge, remove wet clothing and wash the relevant areas of your body that have touched it with warm soapy water.
- Water quality is much improved and similar to water quality before the fire, but we recommend avoiding contact with water in Stony Creek as the sediment is still contaminated and may pollute the water if disturbed.
- Any recent rain may mobilise contaminants along Stony Creek, so avoid contact with water in Stony Creek and any signs of oily sheen or contamination along the waterline.
- Odour levels from the creek have decreased but are still present at times. Avoid the odour if it makes you feel unwell.
- As a precaution avoid eating fish from Stony Creek.
- While water quality is much improved, don't let pets swim in or drink the water.
- Seek medical help if you feel unwell.
This update includes water quality data from 30 August 2018 to the most recent available test results, collected on 23 August 2019.
We have tested water for a range of pollutants from the Stony Creek area and continue to advise not to eat fish taken from Stony Creek. However, based on the results of testing of water quality, there are no concerns regarding fishing and other recreational activities in the Lower Yarra River and Hobsons Bay. We advise avoiding contact with the water and sludge in Stony Creek and to keep pets from swimming or drinking the water.
Past results have shown that a range of industrial chemical solvents, detergents and fire soot particles were washed into Stony Creek. The key chemicals detected were phenol (an industrial chemical and cleaning product), polycyclic aromatic hydrocarbons (fire and soot by-products), lighter petroleum hydrocarbon chemicals called BTEX (benzene, toluene, ethylbenzene and xylene), PFAS, and industrial solvents such as acetone and butanone.
Concentrations of these chemicals were very high in Stony Creek on Thursday 30 August and caused rapid death of fish and aquatic life in Stony Creek and in some cases exceeded human health recreational contact guidelines for several days after the fire. Concentrations of these chemicals have declined significantly over time.
Conditions in Stony Creek have improved considerably since the fire due to dilution by creek flows, chemical degradation and remediation works by Melbourne Water. Water quality in Stony Creek has met human health water guidelines for recreational contact since late 2018.
To aid rehabilitation of Stony Creek, Melbourne Water has undertaken a program to remove contaminated sediments downstream of the fire site by dredging the creek bed from the beginning of April to late July 2019. The figure below shows Stony Creek mean daily flows (ML/day) measured at the Spotswood gauging station (Bena St, Yarraville) from 26/08/2018 to 23/08/2019. The black horizontal bar indicates that the period of dredging has coincided with increased base flows in Stony Creek and periodic heavy rainfalls and creek flows from May to August 2019. These flows may have contributed to further flushing of contaminants from affected areas within Stony Creek.
Results from regular water quality monitoring at fixed sites in Stony Creek
Results for the persistent chemicals perfluorooctanesulfonic acid (PFOS) and the herbicide 2,4-D upstream of the fire site (Quarry Rd) and three sites downstream of the fire site at Cala St, Cruickshank Park and Hyde St from 30/8/2018 to 23/08/2019 are shown below. The red and green lines indicate recreational water quality and aquatic ecosystem guidelines, respectively. These show that the two recent samplings are similar to previous samplings. Note, the very high PFOS levels recorded on 30/08/2018 downstream of the fire site are not displayed on this figure to aid interpretation.
Concentrations of PFOS at all downstream sites were below environmental guidelines on 23/08/2019. Concentrations of the herbicide 2,4-D have declined since November 2018 and were indistinguishable from background levels recorded upstream on 23/08/2019. Levels of 2,4-D recorded at Cala St, Cruickshank Park and Hyde St on 23/08/2019 were similar to background levels recorded upstream at Quarry Rd.
Chemicals presented in previous updates of water quality occurred below detectable levels and are not presented here (e.g. BTEX chemicals benzene, ethylene, toluene and xylene, acetone, methylethylketone, and phenol). Note, that although these chemicals are no longer presented in these reports, EPA will continue to measure and assess these chemicals to ensure they remain below relevant guidelines.
This update includes sediment quality data from 11 September 2018 to the most recent available test results collected on 23 August 2019. This update reports on how sediment conditions have changed over time since the fire.
We have tested sediment at fixed locations for a range of pollutants from the Stony Creek area since 11/9/2018. Although in most cases contaminant levels in the sediment have declined, disturbing the sediments would mobilise contaminants and increase the risk of harm to the environment and human health. We advise avoiding contact with creek sediments in Cruickshank Park until further notice.
Hydrocarbon and copper levels in creek sediments spiked at Cala St on 23/08/2019. Concentrations of C16-C34 hydrocarbons in the sediments of Stony Creek exceeded human health guidelines for recreational contact at Cala St but were below human health guidelines at Cruickshank Park and Hyde St bridge on the 23/08/2019. Concentrations of C10-C40 hydrocarbons in sediments exceeded environmental guidelines at Cala St but were below at Cruickshank Park and Hyde St bridge on the 23/08/2019. Concentrations of copper in sediments exceeded environmental guidelines at Cala St but were below these guidelines or similar to background levels at Cruickshank Park and Hyde St on 23/08/2019. Sediment contaminants have been very variable over time at Cala St. This may be due to movement of more contaminated material from upstream areas during high flows or reflect the small-scale patchiness in distribution of contaminants in the sediments.
Results from regular sediment quality monitoring at fixed sites in Stony Creek
Results for the C16-C34 and C10-C40 hydrocarbon fractions and copper in sediments sampled upstream of the fire site (Quarry Rd) and downstream of the fire site at Cala St, Cruickshank Park and Hyde St from 11/09/2018 to 23/08/2019 are shown in the figures below. The red line indicates human health guidelines for recreational contact with sediments. The green lines indicate aquatic ecosystem guidelines for sediments. Other chemicals presented in previous updates occurred below relevant guidelines and are not presented here (e.g. C6-C10 hydrocarbons and PFOS). Note that although these chemicals will no longer be presented in these reports, EPA will continue to measure and assess these chemicals to ensure they remain below relevant guidelines.