RCA Australia environmental section has recently undertaken targeted site investigations for Hunter Development Corporation (HDC) on the former steelworks site as part of Stage 2 works to determine specific locations of contaminated soils and underground structures. The work was undertaken with the aid of old BHP drawings, site knowledge of former activities and structures, using CAD to determine GPS co-ordinates, followed by test pitting on site.
These investigations were to provide additional information that had not been gathered during the original investigations undertaken by BHP prior to closure and demolition. This information will assist the civil contractor to plan site activities during contouring works which will commence shortly.
Koppers Barrier Cut-off Wall
On behalf of Koppers Carbon Materials and Chemicals, RCA is about to commence supervision of a significant cement bentonite slurry barrier cut-off wall and environmental monitoring at the Mayfield site in Newcastle. The wall, which will be 417m in length and have an average depth of 18m, will isolate DNAPL contaminants (mainly Poly Aromatic Hydrocarbons) originating from tar from groundwater and is to be constructed by Keller Ground Engineering.
RCA’s ongoing involvement with Koppers follows on from many years of assistance at the site with ground assessments, groundwater modeling, assessing remediation options and developing a strategy/action plan and has involved close liaison with DECCW and a NSW Accredited Site Auditor.
The works will last approximately three months and will be followed by further hotspot remediation of free phase hydrocarbons in soils, capping of the site, pump and treat of groundwater contamination and ground water monitoring from an attenuation bore field.
Kooragang Island Waste Emplacement Facility (KIWEF) Closure Works
RCA was engaged by SMEC as specialist geotechnical/environmental sub-consultants as part of the overall provision by SMEC for detailed design, documentation and other services for Hunter Development Corporation. Specifically, RCA has provided review and assessments of previous information as part of a Design Reference Report for the capping of the landfill which, in total, is a 61ha area and comprises nine separate areas.
RCA has had a long history of providing geotechnical and environmental advice to various clients ( Delta EMD, PWCS, BHP, RLMC, HDC, NCIG) at Kooragang Island particularly in connection with landfill closure and redevelopment options. KIWEF is one of the most intensely investigated pieces of land in Australia and RCA understands the ground conditions and issues associated with environmental and geotechnical constraints.
Pasminco Cockle Creek Smelter site
RCA has been sub-consultant to WSP Environmental on the ongoing remediation of the former Pasminco Cockle Creek Smelter in Boolaroo since early 2006. The project manager for the remediation and development of the site is Ferrier Hodgson. The site is being remediated to address, predominantly, lead contaminated soils originating from both dust deposition and the placement of waste materials resulting from the smelter operations which occurred from the late nineteenth century until late 2003.
The remedial strategy is primarily based on the excavation of contaminated soils and waste materials across a site area of approximately 122ha and emplacement of these in a designated containment cell being constructed on site. The site is being remediated to allow for future residential, commercial and industrial redevelopment.
RCA’s involvement with this remediation project involves assistance to WSP Environmental with environmental documentation prior to the commencement of remediation, ongoing remedial supervision and validation sampling from the commencement of the remedial works and preparation of final validation reports to meet the requirements of the NSW EPA Accredited Site Auditor.
Occupational Hygiene Monitoring
RCA has been working with the State Transit Authority to assess risk and improve the occupational environment for bus inspectors and maintenance crews at sites across Sydney and Newcastle. RCA occupational hygienists have recently performed workplace monitoring programmes for diesel exhaust particulate, diesel and paint vapour and noise exposure during which employees wore monitoring equipment and work practices were reviewed. It is hoped that this project will lead to an ongoing mutually beneficial relationship with this critical part of the NSW State Government public transport infrastructure.
Ambient Air Quality Monitoring
RCA currently undertake ambient air quality monitoring in the suburb of Mayfield, NSW for client works associated with the re-development of the former BHP Steelworks site. This monitoring incorporates the real time recording of Total Suspended Particulates (TSP) and Particulate Matter <10µm (PM10) utilising Beta Attenuation Monitors. In addition to the real time monitoring, High Volume Air Samplers (HVAS) are also used to monitor TSP and PM10 particulate matter on a six day run cycle in accordance with the DECCW EPA schedule. In conjunction, a PUF High Volume Air Sampler containing a Polyurethane filter is also utilised to sample Volatile Organic Carbon constituents including Polycyclic Aromatic Hydrocarbons (PAHs) and Phenols.
The BTEX component of the Volatile Organic Carbon monitoring is undertaken using Charcoal Sorbent Tubes attached to a low flow sampling pump. In addition to the Particulate and Volatile Organic Carbon monitoring equipment, a depositional dust gauge is also utilised to monitor the total depositional dust fallout in the Mayfield area.
When analysed in conjunction with local weather station data the real time particulate matter concentrations, weekly particulate matter and volatile Organic Carbon concentrations, and the monthly depositional dust concentrations provide an overall picture of the air quality dynamics of the Mayfield area.