Monday 31 December 2018
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 impacts.
The blue line shows the local waterway Stony Creek.
The current advice is:
- The remediation work being conducted by Melbourne Water has removed much 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 but we still recommend avoiding contact with water in Stony Creek.
- Recent rain may have mobilised 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.
- Don’t let pets swim in the area or drink the water.
- Seek medical help if you feel unwell.
This update includes water quality data from 30 August to the most recent available test results, collected on 29 November.
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 to avoid contact with the water and sludge in Stony Creek and to keep pets from swimming or drinking the water.
The results show 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), 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.
Conditions in Stony Creek have improved considerably since then due to dilution by creek flows, chemical degradation and clean up undertaken by Melbourne Water, including pumping water from the creek. The latest available testing shows that water quality for Cruickshank Park and Hyde street is generally good and meets human health recreational water quality guidelines for recreational contact. The results are now similar to those we are finding upstream of the site of the fire and runoff. Until recently, xylene exceeded aquatic ecosystem guidelines but by 29 November, was recorded at acceptable levels.
Heavy rainfall during Melbourne Cup Day saw 28.4mm falling within 3 hours in Spotswood and another 8mm on 7 November. The creek subsequently rose from 0.12m to 2m at peak flood on 6 November and to 1m high on 7 November. High flows such as this usually result in flushing and dilution of contaminants in waters and sediment redistribution and deposition further downstream. EPA officers were on site during the rain and reported there that was no contaminated runoff from the fire site to Stony Creek. They also carried out inspections at downstream locations as well as collecting water samples on 7 November and sediment samples on 8 November. The results from this sampling and two subsequent regular samplings are presented below.
Other heavy rains (such as those experienced in mid-December) will continue to dilute contaminants in the water and move sediments further downstream. This is likely to be apparent in future monitoring results and is positive for overall rehabilitation of the waterway.
Results from regular water quality monitoring at fixed sites in Stony Creek
Results for monocyclic aromatic hydrocarbons (MAH) at the upstream site (Quarry Rd), the fire site and two downstream sites from 30/8/2018 to 29/11/2018, are shown in the graphs below. The red and green lines indicate recreational water quality and aquatic ecosystem guidelines, respectively.
Results for acetone, methylethylketone, phenol and PFOS at the upstream site (Quarry Rd), the fire site and two downstream sites from 30/8/2018 to 29/11/2018 are shown in the graphs below. The red and green lines indicate recreational water quality and aquatic ecosystem guidelines, respectively. Note, acetone and methylethylketone do not have aquatic ecosystem guidelines.
This update includes sediment quality data from 11 September to the most recent available test results collected on 29 November. This updates reports on how sediment conditions have changed after the high flows on 6 November and other rainfall.
EPA has tested sediments in the creek for two purposes:
1) targeted sampling to help answer specific questions needed to guide the clean-up operations by Melbourne Water and in response to specific events, and
2) to monitor changes over time in contaminants introduced to the creek due to the fire.
The reporting we have done previously has been aimed at the second purpose and we will continue to do this. This update also includes results aimed at meeting the first purpose, helping to better guide the creek clean-up being carried out by Melbourne Water by better defining where the contaminated sediment is.
Results from the targeted sampling
How deep does the contamination extend?
We sampled the surface and deeper (5-10 cm) sediments in Stony Creek at the following locations: (1) Victoria Drive (the fire site), (2) upstream of Paramount Road, (3) near Beaumont Parade/Cala Street and (4) Cruickshank Park near Adaleigh Street.
Contaminated sediments from the fire site appear limited to the surface layer with levels of contaminants in some cases 10 times that found just a few centimetres deeper. Deeper areas have more consolidated sediments with natural organic matter and concentrations of contaminants typical of urban creeks with historical and recent industrial land use practices. The concentrations of many of the contaminants are expected to reduce with increased natural sediment runoff, dilution with streamflow’s and biological degradation over time. It also means that the clean-up work being undertaken by Melbourne Water can focus on just the top few centimetres.
Are different areas within the creek more contaminated than others?
Streams tend to have two main zones within the stream channel. One is the narrow, shallow, more rapidly flowing areas (often called riffles); the other is the slower-flowing, wide and deeper pool areas. The rapid flows in riffles make them erosional and tend not to allow sediment or other material to settle. Pools on the other hand are more depositional in nature, allowing sediment, leaves and other material to settle and accumulate.
The pool sections of the creek upstream of Somerville Road and Francis Street tend to have higher contaminant concentrations from the deposition of sediments washed downstream from the fire site. This is not unexpected and means that Melbourne Water can focus on the pool areas rather than the riffle areas where there is little contamination.
What is the level and nature of sediment contamination in the Stony Creek Backwash?
Parks Victoria requested EPA to test the sediments in the Stony Creek Backwash as the juvenile mangroves were dying off. EPA collected sediments from three locations: a reference site on the upper mudflats which Parks considered possibly less affected by the contamination from the fire, and two potentially more impacted sites along the eastern bank of the Backwash, near the Yarra River.
Concentrations of hydrocarbons in the Backwash adjacent to the Yarra River were slightly higher relative to the reference site on the upper mudflats, with some contaminants being 2 – 5 times higher in the former locations. Other contaminants, including copper and lighter petroleum hydrocarbons (C6-C10) do not appear to have increased relative to the reference site. Herbicides were found in the sediments here although at much lower levels than those found closer to the fire site.
Results from regular sediment sampling at fixed sites in Stony Creek
EPA has tested sediment at fixed locations for a range of pollutants from the Stony Creek area since 11/9/2018. Initially, concentrations of hydrocarbons in sediments in Stony Creek at Cruickshank Park were above human health recreational water quality guidelines.
Although contaminant levels in the sediment have declined, disturbing the sediments would mobilise contaminants and could increase the risk of harm to the environment and human health if touched. EPA continues to advise to avoid contact with the creek in Cruickshank Park until further notice.
PFOS, copper and C6-C10 (which includes the BTEX chemicals) and C10-C40 hydrocarbons in sediments at Quarry Rd (upstream of the fire) and at three downstream locations from 11/9/2018 to 29/11/2018 are shown in the graphs below. The red lines for PFOS and C6-C10 hydrocarbons indicate recreational water quality guidelines. The green lines for copper and C10-C40 hydrocarbons indicate aquatic ecosystem guidelines.
The results show that sediment contamination has improved at Cruickshank Park, but deteriorated at Hyde St (upstream of the bridge) since September 2018. Concentrations of C10-C40 hydrocarbons in sediments sampled on 29 November at Hyde St exceeded aquatic ecosystem guidelines for sediments.
Sediment contamination at Cala Street, approximately 1 km downstream of the fire site, returned to high levels for some compounds on 29 November. Concentrations of C6-C10 hydrocarbons exceeded human health recreational guidelines, and concentrations of copper, zinc (not shown) and C10-C40 hydrocarbons exceeded aquatic ecosystem guidelines for sediments.
Volatile Organic Compounds (VOCs)
VOCs are a large group of chemicals containing carbon and give off vapours into the air. This includes chemicals such as ethanol, acetone, xylene, benzene and toluene. VOCs have a low odour threshold and can be smelt even at low concentrations. It is VOCs that can sometimes be smelt near Stony Creek.
Long term health effects are not expected from short term exposures to VOCs.
Volatile Organic Compounds (VOCs) air sampling along Stony Creek
Air samples have been collected and analysed in residential and sensitive areas near Stony Creek. Any chemical odour in this area was due to the vapours or VOCs coming from the chemicals in the creek from the water run-off from the fire site.
Levels of VOCs in the air sampled have all been well below health guideline levels.
Due to an increase in odours after the large rainfall on 6 November, that moved sediments along the creek, EPA tested for VOCs on 16 November and again in the following week. No exceedances of the health guidelines were found.
There was asbestos containing building materials at the site of the fire and so 24-hour airborne asbestos sampling and testing was first carried out on 31 August 2018 at various locations near the fire site. Further samples have been taken over a 24-hour period on another four occasions.
Results from asbestos monitoring so far have all been below the limit of detection.
Future airborne asbestos monitoring will be done when high winds are forecast by the Bureau of Meteorology during major demolition and clean-up activities.
Disclaimer: EPA monitoring data in support of the West Footscray/ Tottenham fire recovery is preliminary data. EPA has made every reasonable effort to provide current and accurate information, but it does not make any guarantees regarding the accuracy, currency or completeness of that information/data. This data has not been subject to quality control procedures and is subject to change at any time and is provided for general guidance only and should not be relied on as a complete statement.