Management and remediation of the Orica Botany site

In January 2012, the EPA issued Orica with a Management Order under the Contaminated Land Management Act 1997 requiring the company to remediate the site of the former chlor-alkali plant (FCAP). 

Previous investigations at the FCAP identified significant concentrations of mercury in the soil and groundwater, and that mercury had migrated off-site via groundwater.

The remediation project involves removal of mercury-contaminated soil and free mercury to the extent practicable, followed by installation of a capping and containment system to manage the remaining mercury contamination.

Remediation areas

The project will remediate the following areas:

  • An area known as ‘Block G’, where the former mercury cell blocks were located – this area is now covered by a large building, known as the Temporary Emissions Control Enclosure. Block G represents the main area of mercury contamination. 
  • Localised contamination at ‘Block A’, where the former caustic soda storage and filtration area was located – this is an open area covered by landscaping.
  • Localised contamination at ‘Block M’, where the former hydrogen compression, purification and storage area was located – this is a paved open area.

Stages of remediation and progress

  • Stage 1 – excavation of Blocks A and M, soil stabilisation and reinstatement – Completed.
  • Stage 2 – targeted excavation of Block G, soil stabilisation and reinstatement, and relocation and isolation of services – Completed.
  • Stage 3 – levelling and installation of a construction vapour barrier at Block G, decontamination, decommissioning and removal of the Temporary Emissions Control Enclosure and associated emissions control systems, and pilot trench construction.
    Decommissioning of the enclosure commenced in July 2014. For results of independent air monitoring, go to the mercury ambient air monitoring results webpage. Further details on the works to be undertaken can be found on the Orica website.
  • Stage 4 – construction of a cut-off wall, surface profiling of Block G, installation of groundwater monitoring wells, and installation of a permanent vapour capping system.
    Expected to be completed by January 2016

For more information on the EPA’s regulatory role or the progress of the remediation please email the EPA at A questions and answers webpage provides more information relating to the Orica Botany remediation works.

Management Orders issued to Orica

Management Order (9 January 2012)

The primary objective of the Management Order is to set out an appropriate framework to achieve the required environmental and human health outcomes and timeframes for the remediation of mercury contamination on the premises.

Management Order (2 August 2013)

Following its review and assessment of Orica’s Remediation Action Plan and community input, the EPA issued a new Management Order in early August 2013 and added legally enforceable conditions to Orica’s Environment Protection Licence to allow the remediation project to proceed. These instruments establish a comprehensive set of regulatory requirements, which will ensure a high standard of environmental management during the project.

Management Order Amendment (17 October 2013)

The EPA amended the completion dates for Stage 1 – Remediation of Blocks A and M, and Stage 2 - Removal of Mercury Contaminated Soils in Block G, after considering an application submitted by Orica to amend the completion dates.

Management Order Amendment (29 April 2014)

The EPA has extended the completion timing for Stage 3 – Decommissioning and Removal of the Temporary Emissions Control Enclosure. The extension has been granted to allow the EPA to rigorously assess the controls proposed by Orica to implement the Stage 3 works.

Management Order Amendment (16 October 2014)

The EPA has extended the completion date of Stage 4 to January 2016. This takes into account the complexity of the work being undertaken and delays resulting from rigorous assessment processes in Stage 3.

Environment Protection Licence requirements

Orica holds an Environment Protection Licence (no. 2148) for its Botany site. The conditions in this licence will be used to regulate the water, odour, dust and noise impacts of the project. This also includes the general condition that Orica must complete all activities in a competent manner.

Legally enforceable conditions have also been added to Orica’s licence covering important aspects of the project, including air quality management.

Some minor amendments will be required to the Environment Protection Licence as different stages of the project are completed. All changes made to Environment Protection Licence (no. 2148) can be found on the EPA’s Public Register.

Environmental Management Plans

In addition to the EPA’s regulatory requirements, an overarching Environmental Management Plan (EMP) has been developed for the project. This plan is supported by specific plans for air quality, excavation, waste, transportation, and soil and water* management.

These plans established the detailed arrangements for managing environmental issues such as air quality, surface water, dust, noise, waste management and traffic.

The EPA thoroughly reviewed the management plans and Orica must work to these plans to maintain compliance with its Environment Protection Licence.

*NB Groundwater access and use is controlled in the Botany basin.

Independent site audit

An independent site audit will be completed as part of the finalisation of the project. The audit will involve independent expert technical advice or ‘sign-off’ of the contaminated area including investigations/assessments and validation work conducted by a contaminated site consultant.

The site audit process will include issuing a Site Audit Statement and Site Audit Report to confirm that the project has met its remediation objectives.

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