Fitzroy Gasworks Remediation

Enviropacific is currently investigating remediation of the former Fitzroy Gasworks site with remediation works underway to ensure the area is suitable for future development. Detailed information regarding this investigation and 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
8. Q&A’s

Why The Site Is Being Cleaned Up

Historical gasworks activities at 433 Smith Street, Fitzroy North have resulted in soil and groundwater contamination at the site.

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 unit, and the Yarra Council’s public works depot. Heritage 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 recently 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 such as the former Fitzroy Gasworks. We leverage 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.

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Outcomes of the remediation process

Remediation of the former Fitzroy Gasworks will involve a range of activities on site. Once complete, these activities will ensure that the site can be safely developed in the future, through achieving 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, along with future residents that may one day live on the site

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Remediation phases

Remediation of the former Fitzroy Gasworks site will involve three main phases (Phase 1A, Phase 1B and Phase 2), which are outlined below.

Phase 1A: Development of a Draft Strategy
(June-August 2018)

Phase 1A sets the foundation for the project through preparation of the draft Remediation Action Plan (RAP) and the analysis of the existing investigation data 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) will be develloped as part of Phase 1A.

An independent EPA auditor has been appointed to administer the remediation, certifying the final condition of the site is suitable for the future land-use.

Phase 1B: Site Investigation and Strategy Finalisation
(September-December 2018)

During Phase 1B, Enviropacific will conduct additional site investigation and develop a finalised remedial strategy with an associated program of works.

Phase 2: Remediation Works
(January 2019- January 2021)

Phase 2 represents the commencement of remediation works, which will include demolition of buildings and concrete slabs; excavation and removal of soil; and finally, the transfer of the soil to an approved processing facility.

The Valve House will be retained due to their historical and cultural significance. The Porter Prefabricated Iron Store is required to be removed from its current location to allow for site remediation works.

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Overview of the site and remediation areas

The site has an area of 3.9 ha and is located approximately 4 km northeast of the Melbourne CBD, 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.

Context map of the former Fitzroy Gasworks site
Figure 1. Context map of the former Fitzroy 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, alongside Alexandra Parade.

Significant localised contamination has been observed across the site, and 11 targeted remedial areas (RA01-RA11) have been identified (see Figure below). Each remedial area will be further investigated/delineated during Phase 1B, to determine the full extent of contamination.

remediation areas
Figure 2. Remediation areas

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Site Investigation and remediation works

Site Investigation

During Phase 1B, Enviropacific will conduct an additional investigation program in accordance with the DGA report to further analyse/delineate the scale of contamination and to identify any other potential contaminants of concern.

Works undertaken during Phase 1B will include:

• Occasional field visits and investigations by project team members including heritage consultants, flora and fauna specialists, and the EPA auditor

• Drilling sampling 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 to further investigate and visually inspect the underlying geology

• Hand-augering holes for additional soil testing in harder to access locations and the Gore Street easement

The results of the investigations will enable finalisation of the remediation action plan (RAP) and provide additional information to finalise the specifications in relation to demolition, retention, excavation and the remediation process.

Remediation Works

Site management plans and procedures will be prepared by Enviropacific and approved by Development Victoria and the Auditor prior to commencement of remediation works.

These plans and procedures will describe the methods in which the site will be established, managed and maintained throughout the remedial works, including security, works accommodation and amenities, parking, laydown areas and traffic routes.

Below we have provided an overview of the methods and activities you may see occur on the site:

Site Establishment and Hoarding

A 2.4-metre-high hoarding will be constructed 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/heritage structure. The design of the retention system will be completed during the Phase 1B works.

Demolition of Existing Structures

With the exception of the heritage listed Valve House, all buildings and pavements located within the site footprint will be demolished and disposed offsite. Enviropacific will minimise demolition waste to landfill, through their recycling policy to enable future offsite re-use.
Demolition of the above ground structures will be the starting point ofthe remediation process and the most significant works conducted at the site for many years.

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 between January 2019 and December 2020.
An estimated 50,000 m3 of gasworks impacted materials will be removed from the site, the same volume as twenty Olympic sized swimming pools.

Odour Control Enclosure (OCE)

Odour control Enclosure (OCE) structures will be implemented as a primary method of controlling gasworks odours. The OCE structures will be large, temporary, semi rigid and negatively pressurised marquees.
Once excavated, all materials will be placed into EPA licensed trucks and sealed to ensure no emissions from the trucks can occur 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, whilst also mitigating 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 released 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 potentially impacted surface or groundwater.
Contaminated areas of the site will predominantly be managed undercover within Odour Control Enclosures, allowing stormwater to be captured and/or diverted, therefore limiting the amount of surface water runoff coming into contact with contaminated materials.
Water encountered within remedial excavations will be collected, treated and then analysed to confirm its suitability to be discharged to sewer in accordance with the water corporation regulations.

Selective Vegetation Removal

Removal of vegetation is required to allow remedial works across the site footprint. A Vegetation Management Plan will be implemented, that will include the location and identification of all trees to be protected, along with the protocols and permitting requirements for the removal of any unprotected trees.

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 process breaks down contaminants into carbon dioxide and water. Gases generated as part of the process are captured in the form of salt. Dust generated is collected by special filter bags and returned to the process to help form the final product: clean soil. The DTD plant is a fully enclosed system, operated under strict EPA Victoria guidelines.

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Similar case studies

Case 1: RAAF Base Williams, Point Cook
Excavation and thermal treatment of 70,000 tonnes of chlorinated hydrocarbons

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Current and Upcoming Activities

What you may see on site over the coming months:

We will be drilling approximately 30 sampling boreholes using a mobile drilling rig (geoprobe or similar) within the vicinity of the three gasholders and within the footprint of the existing buildings.

These boreholes will extract soil to the depth of up to 12 metres to allow detailed analysis and to confirm the extent of the contamination.

Drilling works will occur during business hours and be very low visual or noise impact to nearby residents or businesses.

drilling-rig
Figure 3. Example Drilling Rig

Approximately 38 test pit excavations will be performed across the site, allowing additional investigate and visually/olfactory inspect of the underlying geology.

test-pit
Figure 4. Test Pit

Machines used for this will include commonly seen construction equipment such as the one in Figure 5.

excavation-equipment
Figure 5. Example Excavation Equipment

For harder to access locations and around the Gore Street easement, our workers will undertake additional soil testing using hand-auger equipment.

hand-auger
Figure 6. Example Hand Auger

Occasional field visits and investigations by project team members including heritage consultants, flora and fauna specialists, and the EPA auditor may also happen on site in the coming months.

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Q&A’s

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 will involve site testing to confirm the extent of ground contamination and finalise 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 12m. The materials will then be removed off-site to a 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 (as part of early works – Phases 1B and 2) 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 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.

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 entrances off Queens Parade, including the former Gore Street entrance.
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 will be 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 spoil 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 20 workers will be involved in the various remediation activities on site at any one time. Parking will be provided for on site. There will be limited need for on street parking. The site induction procedures 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 fitzroygasworks@enviropacific.com.au and you will be responded to within 24 hours (week days only).

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 fitzroygasworks@enviropacific.com.au or call 03 8317 3400