Chemical Stabilisation
Client
Orica Australia
Location
Kooragang Island, NSW
Contaminants
- Arsenic
Immobilisation of Arsenic at the Orica Ammonium Nitrate Facility
Overview
Remediation of the Orica ammonium nitrate facility on Kooragang Island involved treatment of approximately 7,000 tonnes of arsenic impacted soil and concrete, using a chemical fixation and solidification approach that involved formation of iron arsenate. The contaminated waste was immobilised under a DECC Specific Immobilisation Approval, and disposed of to a licensed landfill.
Summary
- Excavation of remediation areas to stockpile.
- Onsite treatment of approximately 7,000 tonnes of soil using a chemical fixation and solidification approach.
- Application to the DECC for an Immobilisation Approval for the treated waste.
- Disposal of approximately 7,000 tonnes of treated contaminated waste as Solid Waste to a licensed landfill.
- Installation of sheet piling system to delineate excavation areas to reduce excavation quantities.
- Extensive site re-instatement works including the importation and placement of over 10,000tonne of clean backfill material and associated re-vegetation works
Client
VicTrack
Location
Spotswood, VIC
Contaminants
- Arsenic
- PAHs
- Asbestos
Victrack Spotswood Railyard Remediation and Civil Works
Overview
Works are nearing completion and have involved the demolition and removal of existing rail infrastructure, excavation and treatment, under approvals from EPA Victoria, of approx 10,000 tonne of Arsenic and PAH contaminated soil to facilitate encapsulation in on-site cell. Following validation of the site Enviropacific will complete civil works for the future distribution facility including stormwater drainage, access road and 20,000m2 of car park sub-base.
Summary
- Demolition of rail infrastructure and buildings
- Obtain EPA approvals for on-site treatment of Arsenic contaminated soil
- Chemical fixation of Arsenic contaminated soils to meet EPA approval and facilitate on-site encapsulation in purpose built cell
- Excavation and construction of 10,000m3 containment cell with secondary leachate collection system
- Placement and compaction of approx 10,000m3 of contaminated soils into cell
- Civil works for future distribution facility including stormwater drainage, access road and sub-base for car park.
Client
Nyrstar
Location
Hobart
Contaminants
- Arsenic
- Cadmium
- Lead
- Mercury
- Selenium
Chemical Fixation of Manufacturing Waste
Overview
Enviropacific are currently undertaking the chemical fixation of manufacturing waste containing high concentrations of arsenic, cadmium, lead, mercury, selenium to facilitate disposal to an EPA licensed landfill as level 2 waste. The works are being conducted on an operational smelting facility in accordance with EPA approvals which include the requirement for stringent environmental and safety controls to eliminate any impact on the surrounding workers and environment. Enviropacific are contracted to manage and treat in excess of 6,000 drums of mercury filter cake, 400 tonnes of sulphuric acid sludge, 200 tonnes of mercury contaminated bricks and other wastes identified during the works. Enviropacific have undertaken extensive treatment trials to ensure a successful treatment outcome while minimising reagent addition and bulking. To enable optimum treatment Enviropacific have employed our hand held XRF unit to provide real-time assessment of contaminant concentrations in each treatment batch as well as to identify historic drum contents. With safety always a high priority Enviropacific procured a custom-built rotating drum grapple for handling and emptying of the drums thereby minimising worker exposure to contaminated materials and mitigating manual handling risks. The chemical immobilisation treatment process generally involves pre-mixing the contaminated materials with a filler agent for liquid adsorption to produce a spadeable product for treatment processing. The pre-mixing is undertaken in Enviropacific’s portable All-Shelter for dust and odour control. Subsequent to the pre-mixing, the contaminated materials will be chemically immobilised through the stoichiometric addition of treatment reagents and high shear mixing in the Enviropacific Hitachi Pugmill.Summary
- Identification and sorting of historical waste utilising our hand held XRF device
- Establishment of environmental and safety controls
- Transportation to treatment area and emptying of over 6000 drums of waste using purpose built rotating drum grapple
- Addition of chemical reagents and high shear mixing with Hitachi pugmill to chemical immobilise the contaminants
- Conformance sampling of waste to ensure leachable concentrations are less than the level 2 criteria
- Disposal of waste to EPA licensed landfill cell
