The Gasworks Community Update | Notification of Works | December 2024

Since our last Community Update, methodology and controls have been finalised with the Independent Auditor to complete the last stages of remediation in the central portion of the site.

These works deal with remediating areas of tar that are present in the soil and are not associated with existing historical structures (e.g. tar wells, gas holders).

A small proportion of this central area is known to contain U1 (gross tar impacts) and U2 (minor-moderately tar impacted soil). Additional investigation has been completed to provide greater certainty on the volume of material expected to be recovered. For context regarding the overall remediation project, the estimated U1 material remaining is under 1% of the current U1 disposed of to date.

The remediation of U1 will commence Wednesday 11 December, with the work to be scheduled around favourable weather conditions and take approximately 2 – 3 days.

The stabilisation and placement of U2 will be completed during the course of the remaining bulk earthworks program, which is expected to be approximately 10 weeks. These works will bring us to the close of remediation works anticipated for February 2025.

The approach for the removal of U1 soil in the central portion of site will be excavated and loaded directly into trucks for removal. Strict, proactive controls and mitigation measures will be implemented handling and loading of the expected materials with excavations to remove the U1 material undertaken in small sections at any one time so that the area of U1 exposed is minimised.

U1 Works

As determined by the Independent Auditor, the controls will be as follows:

• The works will be undertaken in a manner whereby the area under excavation will be exposed only when removal works are underway.
• Proactive use of odour suppressant foam and misting cannons will be used to cover the area to control odour emissions when required.
• Localised odour monitors will be installed adjacent to the area to monitor for odour during the works.

U2 Works

The U2 soils will be excavated, stockpiled and then placed on-site at the prescribed depth. However, for U2 soil that requires treatment, Enviropacific will undertake the following auditor approved methodology:

• Excavation of material and stockpiling whilst under classification assessment.
• Stabilisation of material using powder activated carbon (PAC) at the bottom of the open excavation to assist in controlling of dust.
• Placement of stabilised material under the direction of the auditor on site as the prescribed depth.

As determined by the Independent Auditor, the following additional controls will be implemented:

• All stockpiles of U2 will be proactively covered in odour suppressant whilst undergoing classification.
• Stockpiles that require stabilisation will be placed at the bottom of the open excavation and mixed with PAC.
  • During this activity the area will be covered by an odour misting cannon to suppress dust.
  • Works will not be conducted in windy conditions.
  • Odour suppressant foam will be used to cover the area overnight.
  • Localised volatile organic compound monitors will be installed adjacent the area to monitor for odour during the works.

Boundary monitoring systems will continue to run 24/7 ensuring that we operate within the prescribed limits. If these limits are exceeded, works will stop immediately with additional odour suppressant additive applied. Additionally, a tarp may be applied if the odour level is still above the prescribed limit.

We are looking forward to achieving the completion of soil remediation imminently which will mark a significant milestone for the redevelopment of The Gasworks.