Remediation of landfill for infrastructure works

Overview

Remediation of zones through a former landfill so as to establish a safe workplace for contractors to construct pipe network and other services for the desalination plant. Two major service trenches were excavated to specific design levels and contaminated spoil was transported and disposed offsite to landfill.

All contaminated material was managed in accordance with EPA requirements and asbestos supervision and controls were implemented as required throughout the project. Continuous dewatering was undertaken throughout the excavation works to allow excavation to design levels and contaminated water was treated and disposed to sewer under trade waste. A number of live services, including water, sewer, electrical, telecommunications and stormwater were encountered during excavation works which required removal and/or diversion and re-instillation to allow excavation works to proceed. This included the removal and replacement of a live section of sewer rising main. Upon completion of excavation works a geofabric marker was installed to the trench profile and trenches were backfilled under AS1 geotechnical supervision.

Summary

• Excavation of service trenches through a former landfill to specific design requirements
• Transport and offsite disposal of approximately 10,000m3 of contaminated soil generated from the excavation of the service trenches
• Contaminated materials management throughout the duration of the excavation works including materials tracking and asbestos management
• Location, removal and/or diversion and re-instillation of a number of services (water, sewer and stormwater) to allow continuous excavation of the service trenches. This included the removal and replacement of a live section of sewer rising main.
• Continuous dewatering throughout the excavation works, treatment and disposal of contaminated water to sewer under a trade waste agreement
• Installation of geofabric marker layer to trench profile
• Controlled backfilling of service trenches with engineered fill under AS1 geotechnical supervision

BCD Technologies Construction Works, Narangba QLD

Overview

Enviropacific were contracted by BCD Technologies to manage the civil and construction works for the upgrade of the onsite Water Treatment Plant and recently acquired thermal desorption unit. Enviropacific managed the constructions works in accordance with the approved design and value added in the supply chain for the execution of the works.

All works completed were inspected and approved by an independent engineer. Civil earthworks involved cutting the formation to the design level and excavating, stockpiling and storing soils for future remediation works. Enviropacific managed the installation of 52 timber piles beneath the water treatment slab, construction of lower reinforced concrete slab for the water treatment plant and the installation of retaining walls for split level of works. Enviropacific also executed the installation of upper concrete reinforced slab for the direct fired desorption plant. Enviropacific managed the installation of eight storage tanks and plumbing works for the waste effluent treatment system and storm water management system.

Summary

• Excavation earthworks.
• Installation of 52 timber piles.
• Construction of reinforced concrete slabs.
• Construction of block work retaining walls.
• Backfilling behind retaining walls.
• Water Treatment Plant equipment installation.

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

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.

Excavation and remediation for construction of Charlestown extensions

Overview

Project involved all bulk and detail excavation and remediation works to enable the construction of the new extension of the Charlestown Square Shopping Centre, The New Charlestown Bowling Club, Kahibah Child Care Centre, St Johns Sport Field and all road works required for the construction.

Summary

• Disconnection of existing services and removal of redundant underground stormwater and sewer service
• Strip to stockpile 6,500 m3 of topsoil.
• Excavate, segregate, cart, spread for re-use in a different site and compact 20,000 M3 of inert/VENM soil.
• Excavate and dispose of 4,000m3 of Asbestos impacted Soil.
• Cut to fill 30,000m3 of Asbestos Impacted soil followed by capping with marker layer and 6,000m3 of engineered clay cap.
• Chase and excavate to stockpile 850m3 of slag impacted soil.
• Construction of on-site slag encapsulation cell including the supply and installation of GCL layer.
• Bulk excavation, batters and sub grade trimming to accommodate all roads, basements, car parks and ground slabs.
• Detail excavation required for the installation of new services, pile caps and foundations required for the construction.

Former ADI Site Remediation – St Marys

Overview

The ADI Site was a former Commonwealth Government Business entity that used the property as a munitions factory from 1940 up until its closure in 1993. Residential development commenced in 2004 with Enviropacific conducting ongoing remediation works on future residential stages.

Summary

• Remediation of asbestos contaminated soils in various areas and removal of AC conduits.
• Remediation of PCB contaminated soils
• Removal of SMF encased piping under former rail bridge.
• Removal and remediation of redundant service infrastructure including sewers, stormwater pipes, and signal cables. Care was taken around all sewer lines due to the possibility of traces of TNT and RDX. Implementation of GPS Materials Tracking System for removal of all removed infrastructure.
• Enviropacific worked closely with UXO contractor Gtek during remediation to assess for unexploded ordinances. All remediated areas were subsequently approved for residential development with site auditor sign off under NEPM A guidelines.
• Sourcing and management of the importation of 20 000m3 of fill

Acid Sulfate soil and water treatment during the Narrabeen creek sewer installation

Overview

Summary

• Neutralisation of acid sulphate soils using agricultural lime.
• Offsite disposal of treated soils as general solid waste
• Treatment of groundwater by addition of a coagulant and flocculent to reduce the turbidity below 30 NTU
• Addition of a caustic (sodium hydroxide) to ensure pH is between 6.5 and 9 prior to discharge
• Controlled Discharge of water to nearby field

Treatment of acid sulphate soils at Sydney airport

Overview

The contract works involve the treatment and management of approximately 12,000 tonnes of acid sulphate soils and potential acid sulphate soil excavated as part of Runway 25 - Runway End Safety Area project for Baulderstone Pty Ltd.

Summary

• Treatment of ASS and PASS by addition and mixing of liquid lime.
• Sampling and lab testing of treated soils to confirm successful treatment.
• Management of soil during and after treatment to strict airport environmental and operational requirements.
• Management and treatment of rainfall runoff potentially acid affected.

Remediation of the former Armidale Gasworks Site

Overview

This project involved the remediation of the former Armidale gasworks site required to enable construction of the future West End Market Place in Armidale, NSW. The site area is approximately 1.7 ha.

Summary

• Installation and maintenance of erosion and sediment control measures
• Disconnection of existing services and demolition and removal of former gasworks infrastructure
• Demolition and removal of redundant underground stormwater, gas and sewer services
• Excavate, segregate and stockpile of approx. 25,000 tonnes of Inert, Solid, Industrial and Hazardous waste
• Conduct Hazardous waste treatment trial
• Remediation of contaminated soils therein including treatment of 15,000 tonnes of coal tar impacted soils
• Design, supply, install and operate water treatment unit to treat 400 km3 of contaminated underground water prior dispose to sewer
• Construction of 8 m vertical barrier wall around perimeter of 1.7 ha former Armidale gasworks site, barrier layer, GCL, drainage layer, gas vents and monitoring wells
• Supply and placement of engineered base materials across site
• Excavation, treated timber piles, steel and concrete to pile caps, stripfootings, loading deck and all foundations for the West End Market Place

Bioremediation of sullage material – West Belconnen landfill

Overview

Summary

• Establishment of groundwater wells and a monitoring program.
• Removal of the sullage waste from pond 5, mixing with green waste and formation of windrows.
• Installation of a clay cap, topsoil and dryland grass over the empty pond areas.
• Regular monitoring and turning of the windrows.
• Completion of bioremediation and re-use of material onsite.
• Installation of a clay cap, topsoil and dryland grass over the windrow area.

Remediation and Rehabilitation of Wirlinga Liquid Waste Facility

Overview

Remediation and rehabilitation of Wirlinga Liquid Waste Facility, Albury NSW. The works involved the extraction, pre-treatment and off-site disposal of TPH impacted waste water, excavation and treatment of approx 7000m3 of sludge and sediments resulting from the former liquid waste facility.

Sludge and sediments were bioremediated on site over a 6 month period to concentrations that allowed off-site disposal to the local landfill.

Summary

• Pre treatment of liquid waste prior to off-site disposal
• Excavation and bioremediation of sludge’s and sediments
• Nutrient and green waste addition and mixing utilising a soil recycler (Retera)
• Transport and stockpiling into windrows
• Off-site disposal

Remediation of State Coronial Services Centre

Overview

Summary

• Highly odorous and volatile contaminants
• Establishment of Odour Control Structure & Air extraction / treatment system
• Development & implementation of detailed management plans
• Stringent air monitoring programme
• Treatment of Category A soil to allow offsite disposal
• Classification and offsite disposal EPA licensed landfill

Chemical Fixation of Manufacturing Waste

Overview

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