Environmental site assessment, remediation and compliance monitoring during site redevelopment for statutory environmental audit: Stage 1, Fyansford Green Development

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Summary of works

ESG Environmental (ESG) was engaged by ICD to conduct a Detailed Site Investigation (DSI) of the former Australian Portland Cement Company Ltd /Adelaide Brighton Cement Co Ltd cement manufacturing works, which formed part of the greater Fyansford Development (Stage 1). The site is currently being redeveloped for a low density residential land use. The property was first developed as a cement works in the mid 1920s.

A comprehensive site history desk top study (Phase 1) was initially undertaken for the Stage 1 development (comprising eight Audit Areas) to identify issues of potential environmental concern at the site. This information was then used to develop detailed soil and groundwater sampling and analysis and to develop quality plans (Work Plans) for intrusive investigations for various audit areas across the site.

The intrusive soil and groundwater investigations (Phase 2) were designed to provide site coverage as well as targeting identified former features and activities of potential concern. The investigations involved the collection of soil samples from over 320 locations across the site and the installation and sampling from over 120 groundwater monitoring wells.

The intrusive soil investigation identified arsenic, chromium (including hexavalent chromium), copper, nickel, zinc and asbestos contamination, predominantly within surface fill in discrete areas on the site. Some areas contained leachable metals that had the potential to impact groundwater and the Moorabool River adjacent to the site.

Recommendations were made for the safe management of the metal and asbestos impacted soils during redevelopment works, via an Auditor approved  Construction Environmental Management Plan (CEMP) developed by ESG. Subsequent soil remedial works involved the excavation, treatment and reuse of impacted and leachable soils. ESG also assessed soils at off-site locations for use at the development.

Groundwater investigations identified elevated metal (including hexavalent chromium) and nitrate concentrations that had the potential to impact the Moorabool River. To mitigate the risk of potential adverse impacts to the river, the contaminated groundwater was remediated in-situ by injection of a carbon source reagent. This culminated in an Auditor or EPA Clean Up to the Extent Practicable (CUTEP) determination being achieved for the impacted Audit Areas.

All works were conducted without safety, health or environmental incident or injury.

Project highlights

Client: ICD Property Pty Ltd (ICD)
Client contact: Ms Alice Smith, Development Manager
Duration: 2013 – ongoing

Specific issues / problem solving

• Development of soil reuse criteria to comply with the requirements of the Audit

• Undertaking of laboratory and field trials for selection of preferred groundwater treatment reagent and methodologies

• Design of site specific reagent delivery system

• Undertaking of laboratory trials for selection of preferred blends of additives and reagents for the treatment of impacted soils

• Scaling up of impacted soil treatment methodologies.

Key services

• Desktop study investigation

• Development of Work Plans for the environmental assessment of the siteSoil and hydrogeological investigations involving installation of over 120 wells

• Statistical and risk based assessment of contaminants of concern

• Groundwater modelling

• Remediation of impacted soils and groundwater

• Evaluation of soils proposed to be imported to the site

• Development of site specific soil reuse criteria for development earthworks

• Preparation of Construction Environmental Management Plan (CEMP) and compliance monitoring

• Reporting for Audit requirements.

Benefits

• On-site treatment and reuse of impacted soils, avoiding significant off-site disposal costs

• Implementation of cost effective and efficient groundwater remediation technology

• Deliverables provided (including Certificates of Environmental Audit for some audit areas) within timeframes and to the satisfaction of the client.