Fitzroy Gasworks Remediation
The former Fitzroy Gasworks site has a long industrial history and is heavily contaminated. To ensure the site is clean and safe for future development, the Environment Protection Authority Victoria (EPA) has issued a clean-up notice. Enviropacific has been appointed by the State Government to remediate the site.
Detailed information regarding the remediation process is provided below, including:
1. WHY THE SITE IS BEING CLEANED UP
2. OUTCOMES OF THE REMEDIATION PROCESS
3. REMEDIATION PHASES
4. OVERVIEW OF THE SITE AND REMEDIATION AREAS
5. SITE INVESTIGATION AND REMEDIATION WORKS
6. SIMILAR CASE STUDIES
7. CURRENT AND UPCOMING ACTIVITIES
Why The Site Is Being Cleaned Up
Historical gasworks activities at 433 Smith Street, Fitzroy North have resulted in soil and groundwater contamination.
Built in 1859, the Fitzroy Gasworks was a key supplier of gas to the Melbourne area, until production ceased in 1927, with the site remaining operational as a workshop and gas storage facility until the 1970s. The site was redeveloped into its current layout in the early 1980s.
The site comprises two parcels of land, the former gasworks, currently occupied by light industrial units, and Yarra Council’s public works depot. Structures in the form of the Valve House and a Porter Prefabricated Iron Store have been assessed as being of historical and social significance.
Environment Protection Authority (EPA) Victoria issued a clean-up notice for the site in 2014, with works initiated to address the requirements of this notice. Development Victoria has appointed Enviropacific to complete remediation of the site under the supervision of an EPA accredited auditor. Remediation works will be undertaken across the former gasworks and Council depot sites, as both areas are affected by contamination.
Enviropacific is a privately owned, market leading, specialist infrastructure service provider, delivering sustainable engineering and applied science solutions to make environments and communities safer and healthier.
The company was formed in 2001 and has extensive national experience in the remediation of contaminated sites similar to the former Fitzroy Gasworks. Enviropacific leverages industry knowledge, expertise and project management to improve environments and to help stop, prevent and reverse environmental damage.
More information about us and the work we do can be found here.
Outcomes of the remediation process
Remediation of the former Fitzroy Gasworks will involve a range of activities on site, with the aim of achieving a statement of environmental audit. This audit will determine that the site is suitable for future development.
Remediation activities will achieve the following outcomes:
• Soil quality being suitable for mixed-use development
• Groundwater quality being suitable for mixed-use development
• Mitigation and management of residual soil vapour
• Protection of the existing community and future residents that may one day live on the site.
Remediation of the former Fitzroy Gasworks site involves three main phases (Phase 1A, Phase 1B and Phase 2), which are outlined below.
• Phase 1A: Development of a Draft Strategy (complete)
Phase 1A set the foundation for the project through preparation of the draft Remediation Action Plan (RAP) and the analysis of data from prior investigations to develop a Data Gap Analysis (DGA) report. Preparatory planning documents, including a draft Asset Protection Plan, draft Cultural Heritage Management Plan and a draft Interim Works Plan (outlining the site conditions at the completion of the remedial works) were developed as part of Phase 1A.
An independent EPA auditor was appointed to verify and approve the remediation, certifying the final condition of the site is suitable for the future land-use.
• Phase 1B: Site Investigation and Strategy Finalisation (complete)
During Phase 1B, Enviropacific conducted additional site investigation and developed a finalised remedial strategy with an associated program of works.
• Phase 2: Remediation Works
(Early 2019- Mid 2021)
Phase 2 represents the commencement of remediation works, which will include demolition of buildings and concrete slabs; excavation and removal of soil; and the transfer of soil to an approved processing facility.
The Valve House will be retained due to its historical and cultural significance. The Porter Prefabricated Iron Store is required to be removed from its current location to allow for site remediation works.
Overview of the site and remediation areas
The site is located in Fitzroy North, at 433 Smith Street, and has an area of 3.9 hectares. It is It is surrounded by the suburbs of Fitzroy, Clifton Hill, and Collingwood. A map is provided below showing the site and adjacent roads: Smith Street, George Street, Queens Parade and Alexandra Parade.
Figure 1. Context map of the former Fitzroy Gasworks site. A – Council Depot Site / B – Former Gasworks Site.
Soil investigations have identified contamination in fill, natural clay and the underlying rock across the site. Contamination can be traced back to historical land-use and activities, with the highest concentrations of contaminants located in or around the footprints of the three former gas holders, located along the southern boundary of the site, along Alexandra Parade.
Site Investigation and remediation works
Significant localised contamination has been observed across the site. Earlier investigations had identified 11 targeted remedial areas. During Phase 1B, Enviropacific conducted an additional investigation program in accordance with the Data Gap Analysis (DGA) report to determine the full extent of contamination on site and to identify any other potential contaminants of concern. Four new remedial areas were identified and can be seen in the updated map of remediation areas below.
(Left) Figure 1. Original Remediation Areas
(Right) Figure 2. Updated Remediation Areas
The key contaminants in soil at the site are:
• Coal tar
• Associated organics including Total Petroleum Hydrocarbons (TPH), Benzene, Ethylbenzene, Toluene, Xylenes, and Polycyclic Aromatic Hydrocarbons
Cement bounded asbestos has been found in four locations (asbestos will be removed from buildings prior to demolition)
The key contaminants in groundwater at the site are:
• Coal tar, benzene, naphthalene, ammonia and cyanide
Works undertaken during Phase 1B included:
• Field visits and investigations by project team members including heritage consultants, flora and fauna specialists, and the EPA auditor
• Drilling sample boreholes using a mobile drilling rig (geoprobe or similar) within the vicinity of the three gasholders and within the footprint of the existing buildings
• Test pit excavations that further investigated and visually inspected the underlying geology
• Hand-augering holes for additional soil testing above major utilities that run north to south through the centre of the site
The results of the investigations enabled the finalisation of the remediation action plan (RAP) and provided additional information to finalise the specifications in relation to demolition, retention, excavation and the remediation process.
Prior to commencement of remediation works, site management plans and procedures will be prepared by Enviropacific and approved by the site Superintendent. Selected documents will be approved by government bodies (DELWP and City of Yarra).
These plans and procedures describe the methods in which the site is established, managed and maintained throughout the remedial works.
Similar case studies
Case 1: RAAF Base Williams, Point Cook
Excavation and thermal treatment of 70,000 tonnes of chlorinated hydrocarbons
Current and Upcoming Activities
Below is an overview of the methods and activities you may see occur on the site during Phase 2:
• Site Establishment and Hoarding
A 2.4-metre-high hoarding will be constructed in stages around the site. This hoarding will protect the site, provide security, and may also be used to display images relating to the history of the site and provide ongoing information relating to the remedial program.
• Retention Wall Construction
The former gas holder infrastructure is located in close proximity to the Alexandra Parade boundary and the heritage listed Valve House and, as such, a retention system will be required to facilitate excavation to depth in these areas. A temporary retention system comprising of bored piles with capping beam, anchors and shotcreting will be installed to mitigate undermining of the adjacent roadway and heritage structure. The design of the retention system was commenced during the Phase 1B works. Whilst works are being conducted to install the retention system along both George Street and Smith Street it will be required to close the footpaths temporarily. Traffic Management will be in place to direct foot traffic and notify vehicles.
• Demolition of Existing Structures
With the exception of the heritage listed Valve House and the Porter Store, all buildings and pavement located within the site footprint will be demolished and disposed offsite. Demolition of the above ground structures will signify the start of the major remediation works.
Enviropacific maintains a recycling policy for demolition waste with the aim of minimising the volume of waste sent to landfill.
• Excavation Works
Remediation will require excavation and removal of soil to a depth of up to 10 metres in some areas of the site. Excavation works will be conducted via a staged approach, across the entire site. Remedial excavation works are scheduled to be undertaken from mid2019 to December 2020.
An estimated 50,000m3 of gasworks impacted materials will be removed from the site, the same volume as nearly twenty Olympic sized swimming pools.
• Odour Control Enclosure (OCE)
Odour Control Enclosures (OCE) will be implemented as the primary method of controlling gasworks odours. The OCE will be large, temporary, semi-rigid and negatively pressurised marquee style structures.
Once excavated, all materials will be placed into EPA licensed trucks and covered to minimise potential for fugitive emissions during transport. Materials will be loaded inside the OCE structures, with vehicles entering via fast action roller doors.
• Emission Control System (ECS)
The OCEs will be fitted with Emission Control Systems (ECS) providing air filtration to maintain a safe working atmosphere within the enclosures for site personnel and to mitigate the release of potentially harmful emissions to the surrounding atmosphere.
The ECS extracts the contaminated and odorous atmosphere within the OCE and filters the vapour through carbon beds and high efficiency particle air (HEPA) filters, resulting in clean air being discharged to the atmosphere. Monitoring of the ECS discharge air will be conducted daily.
• Water Treatment
A purpose-built Water Treatment Plant (WTP) will be constructed on site to treat impacted surface or groundwater.
Contaminated areas of the site will predominantly be managed undercover within OCEs, allowing stormwater to be controlled and to limit the amount of surface water runoff coming into contact with contaminated materials.
Stormwater encountered on site within remedial excavations will be collected, treated and then analysed to confirm its suitability to be discharged to sewer in accordance with regulations.
• Selective Vegetation Removal
Due to the extent of contamination on site, trees will be removed as part of the remediation works to satisfy the requirements of the EPA clean-up notice. To mitigate the loss of the existing vegetation, Development Victoria is committed to replacing trees on a minimum one-to-one basis. More information about tree planting will be available in the Development Plan for the site, once this is finalised. A Vegetation Management Plan will be implemented to ensure that protocols and permitting requirements for the removal of any unprotected trees are being followed.
• Off-site Soil Treatment
Contaminated soil will be transported to Enviropacific’s new soil and waste treatment facility, SOLVE, located in Altona, Victoria. The SOLVE facility applies the most advanced direct thermal desorption (DTD) treatment technology. The DTD plant is a fully enclosed system, operated under strict EPA Victoria guidelines.
What is remediation and why does it need to take place?
Remediation is the removal of pollution or contaminants from environmental sources such as soil, groundwater, sediment or surface water.
The Environment Protection Authority (EPA) has issued a Clean Up Notice and extensive remediation is required to create a safe and clean environment for future development.
The removal of this contaminated soil will deliver a cleaner, safer environment for the people of Fitzroy North and surrounds.
How long is remediation going to take place?
We estimate that remediation works will take approximately two years and commence in early 2019.
The works will be delivered in three phases:
• Phases 1A and 1B works involved site testing to confirm the extent of ground contamination and finalisation of a remediation action plan (RAP) for approval by the EPA.
• Phase 2 works will involve the excavation of contaminated material to a depth of up to 10m. The materials will then be removed to an off-site licensed processing facility.
What noise will be created during this process and what are you doing to mitigate excessive noise?
The main sources of noise are likely to be truck movements to and from site, demolition, piling and concrete breaking.
Noise and acoustic controls will be established in accordance with the approved Construction Environmental Management Plan (CEMP). All activities will be completed in accordance with Council and EPA regulations.
What odour will be created and is it safe?
During Phase 2 an Odour Control Enclosure (OCE) will be erected over excavation areas. This is to minimise any vapours emanating from the site and to ensure public safety is maintained at all times.
How will dust be managed?
Dust will be managed in accordance with the Environment Protection Act 1970. Excavation works will be conducted within large enclosures and existing roads within the site will become haul roads to reduce the potential for generating dust. Water trucks will be on standby to address any dust generated. Wheel washes will also be placed at exits to reduce the potential for soil to be tracked onto public roads.
What are the trucking safety protocols for remediation works?
Transport and disposal of materials will be undertaken in accordance with the Environment Protection Act 1970.
Will there be an impact on traffic and if so, how will you manage this?
Traffic management signage and/or personnel will be utilised in accordance with a site-specific traffic management plan throughout the remedial works. Vehicle ingress/egress will be managed to minimise impacts to local residents, with vehicles utilising the existing gates off Queens Parade.
Regular correspondence will be issued throughout the remedial works program to keep residents informed of upcoming works and any potential traffic impacts.
What happens if there is an accident/spill when transporting the soil?
All trucks are required to have an appropriate spill kit readily available at all times during transportation. If soil is spilled, it would be contained and placed back in the truck. It should be noted that a soil spill will not spread like liquid.
All EPA registered truck drivers are trained in appropriate emergency response procedures.
How many workers will be employed on site and where will they park?
We anticipate that up to 30 workers will be involved in the various remediation activities on site at any one time. Parking will be provided for on site and therefore, there is no anticipated requirement for on street parking. Site induction procedures prepared by Enviropacific will reinforce these protocols.
How can I make a complaint if noise is too loud?
If you would like to report any incidents that you have seen on site or are concerned with levels of noise, please email firstname.lastname@example.org and you will be responded to within 24 hours (week days only).
Why do trees need to be removed from site?
Due to the extent of contamination on site, and to satisfy the requirements of the Environment Protection Authority (EPA) clean-up notice, large areas need to be excavated. Unfortunately, many of the trees on site are located in the areas requiring excavation (see Figure 2 remediation areas map). Additionally, a piled wall will be installed to support the footpaths and road on the northern side of Alexandra Parade, as there will be deep excavations in this part of the site. Trees located in these areas will need to be removed prior to work commencing.
A Vegetation Management Plan (VMP) will be implemented to ensure that protocols and permitting requirements for the removal of trees are being followed.
What is the Vegetation Management Plan (VMP)?
The VMP was developed to identify and protect trees that are to remain on site throughout the remediation works and to protect trees located off site that could be impacted by the works. The VMP also establishes protocols for the necessary removal of trees on site required to complete the excavation and remediation of contaminated soil.
How many trees will remain on site?
Enviropacific has committed to retain three trees located outside of the remediation areas across the site. These are Australian native trees that provide a link to the existing vegetation and are located in the northeast portion of the site. Enviropacific will implement Tree Protection Zones (TPZs) to safeguard trees which are to remain on site.
What are Tree Protection Zones (TPZs)?
Tree Protection Zones provide a buffer between construction activities and the tree trunk and crown, which allows for suitable space for the preservation of sufficient roots to maintain tree health.
The tree protection distance method outlined in the current Australian Standard, AS4970-2009 ‘Protection of trees on development sites’ will be implemented for TPZs. TPZs will be established and fenced prior to the commencement of works on site.
An example of the establishment of a TPZ is shown in Figure 1.
Figure 1. Example of TPZ Establishment
The methodology of the above figure is below,
1. Chain wire mesh panels with shade cloth (if required) attached, held in place with concrete feet.
2. Alternative plywood or wooden paling fence panels. This fencing material prevents building materials or soil entering the TPZ.
3. Mulch installation across surface of TPZ (at the discretion of the project arborist). No excavation, construction activity, grade changes, surface treatment or storage of materials of any kind is permitted within the TPZ.
4. Bracing is permissible within the TPZ. Installation of supports should avoid damaging to the tree.
Will offsite trees be impacted by the remediation works?
It is not anticipated that trees external to the site boundary will require removal. Boundary hoarding will be installed for security reasons and will act as a barrier, preventing trees external to the site from being damaged during the works. Truck movements on and offsite will be assessed and monitored.
Will trees be replaced on site?
Replanting or offsetting of vegetation removed as part of the remediation works is outside Enviropacific scope of works. However, to mitigate the loss of the existing vegetation, Development Victoria is committed to replacing trees on a minimum one-to-one basis. More information about tree planting will be available in the Development Plan for the site, once this is finalised. The community will have an opportunity to be involved in preparation of the Development Plan. More details on this process can be found here.
What are the plans to protect fauna?
The fauna protection and removal process within the Fitzroy Gasworks site will be undertaken in accordance with the Wildlife Assessment Report developed by Practical Ecology.
This report will inform the development of the Wildlife Management Plan which will ensure animals are managed appropriately and that all steps are taken to ensure the safe and humane removal of fauna.
As per the requirements in the Wildlife Management Plan, an appointed zoologist from Practical Ecology will, where practicable, remove the fauna within the site that would be directly affected by the tree felling. This will happen prior to the removal of trees from the site.
Throughout all remediation works, care will be taken to ensure that adjacent vegetation is not disturbed during either vegetation removal or demolition works. To minimise disturbance and the potential displacement/injury of arboreal fauna that may be sheltering within other trees, the extent of their canopies will be clearly identified prior to works commencing. Contractors will be made aware for the potential of fauna and vegetation on site and that these fauna also require a qualified zoologist for salvage/translocation, as required.
Who do I contact to find out more information about remediation or report any behaviours seen on site?
Enviropacific are leading the remediation works at Fitzroy Gasworks. If you have any questions, please email email@example.com or call 1300 510 407.