Tuesday 13 August 2019
Environment Protection Authority Victoria (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 27 June 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), polyaromatic 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 clean up undertaken by Melbourne Water. Heavy rainfall and creek flows during November and December helped to dilute and flush the creek of water-borne contaminants, and aided in the movement of contaminated sediments downstream. The latest results show that water quality in Stony Creek meets human health water quality guidelines for recreational contact.
Melbourne Water began removing contaminated sediments via dredging from sections of Stony Creek downstream of the fire site on 1 April 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 30/06/2019. 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 throughout May and June 2019. These 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 27/06/2019 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 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 Cruickshank Park have declined through time and at all downstream sites were below environmental guidelines on 27/06/2019. Concentrations of the herbicide 2,4-D have declined since November and remain below human health guidelines, but remain above background levels at Cala St and Cruickshank Park. It is unclear whether elevated levels of 2,4-D are due to residual impacts associated with the fire or related to ongoing contamination from local sources at the downstream sites.
Other 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 27 June 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 the creek in Cruickshank Park until further notice.
Concentrations of C16-C34 hydrocarbons at Cala St exceeded human health guidelines for recreational contact on 03/05/2019 and 17/05/2019 but fell below these guidelines by the 31/05/2019. Concentrations of C16-C34 hydrocarbons at Cruickshank Park remained below the recreational guidelines during May 2019. Concentrations of C10-C40 hydrocarbons in sediments continued to exceed environmental guidelines at sites downstream of the fire and remained significantly above background levels recorded upstream of the fire site at Quarry Road. Concentrations of copper in sediments at Cruickshank Park continued to remain above environmental guidelines. As with concentrations of C16-C34 hydrocarbons, copper concentrations spiked on 03/05/2019 at Cala St. High variation in sediment contaminant levels over time at Cala St and Cruickshank Park may reflect the movement of contaminated sediments during high flow events.
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 31/05/2019 are shown 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.