Due to the fact that the reported asbestos containing materials at the Port Kembla site are contained within soil and fill of a non-homogenous nature the approach taken for identifying the extent of asbestos contamination must be suitable.
Initially, identification of ACMs will take place using a visual survey by qualified personnel in accordance with AS4964 Method for Qualitative identification of asbestos in bulk samples.
Any sampling of the area should take place based on the "worst case scenario" as determined by thorough risk assessment. When defining the area for a generic survey and assessment the number of ACM identification samples must be determined.
In the event ACMs are found within the rubble pile a course of action must be determined. Any removal of asbestos from the site must take place in accordance with WHS Regulation 2011 and the Code of Practice - How to Safely Remove Asbestos.
To ensure unprotected personnel do not come into contact with asbestos and airborne fibres barricading of the site is a priority in the event ACMs are identified. Barricading should be performed in accordance with Code of Practice - How to Safely Remove Asbestos.
When establishing barricades for asbestos removal work or for contaminated asbestos rubble, the work area should be clearly defined to ensure:
non-essential personnel do not enter;
the requirement to wear PPE in the area is communicated clearly;
the site is clearly delineated and warns persons that asbestos containing materials are present. All signage to be in accordance with AS1319 Safety signs for the occupational environment.
Airborne monitoring will be required in order to determine the function of control measures including the use of fog spray to keep the rubble pile damp.
Preliminary visual examination
The initial method of identification of ACMs is via a visual site inspection carried out by a competent person. This will allow for an overall depiction of the potentially contaminated site to be determined and assist in the formulation of a representative sampling program at the contaminated site.
A full visual examination of the area will provide the competent asbestos surveyor a way to identify homogenous and non-homogenous samples of what may potentially be an ACM.
Following initial visual inspection of the rubble pile various pieces of homogenous material most likely to contain asbestos, as determined by the competent person (possibly fibro, lagging and insulation materials - where visible to the naked eye), will be selected to send for positive identification at a NATA accredited laboratory. These bulk samples will go some way in determining the presence of friable or non-friable asbestos in the rubble pile.
Soil sampling
Soil sampling must be representative of the site at which the soil was delivered and a process to determine a representative sample will be devised by the competent person responsible for conducting the survey. Quantitative risk assessments are required in order to satisfy the regulatory bodies notions of the extent and severity of asbestos . Such risk assessments require a sampling strategy representative of the site.
Representative sampling of soil and sites is difficult to achieve and should be undertaken using a reputable documented method such as outlined in AS4482.1 Guide to the investigation and sampling
of sites with potentially contaminated soil Part 1: Non-volatile and semi-volatile compounds.
Having performed a preliminary examination at Port Kembla to determine the nature of contaminants i.e. asbestos and the possible locations of contamination, a detailed representative survey may be devised that can satisfy the regulator as to the condition of the rubble pile.
The objectives of a detailed survey are to:
assess the status of contamination;
establish the distribution of contamination (depth and breadth);
identify the source of contamination.
Since it is known the material being surveyed was delivered from Barangaroo development site the detailed survey will focus primarily on the status and distribution of the asbestos in the rubble pile.
The soil sampling strategy is to be determined based on factors specific to the site at Port Kembla including what the site will be used for once development is completed (i.e. a port facility), the objective of the sampling strategy (i.e. determination of the extent and status of contamination at the site); the distribution of contamination; the pattern of sampling and must consider uncertainty of sampling.
Ultimately the objective of the soil sampling survey and associated lab assessment of the samples would be to prove the site free from asbestos contamination, within acceptable confidence levels, in order to apply for a new resource recovery exemption from the EPA and deliver soil from Barangaroo to Port Kembla once more.
In order to ensure that representative sampling takes place at the Port Kembla site the sample locations must be selected without bias and systematically. The sampling pattern to be employed at the Port Kembla will be of a systematic pattern which will ensure that there is no bias in determining the sampling points and there will be no clustering of sampling points. The first sampling point will be chosen at a random point in the rubble pile delivered from Barangaroo and all other sampling points will be selected from within a grid pattern overlaid onto the site.
Each sample will be selected from defined points at regular intervals from within the grid pattern and given a grid reference that correlates with GPS coordinates overlaid onto the site and will be recorded in a sample log, numbered and note made of location, depth of sample and coordinates. Each sample point will be physically flagged prior to sampling to ensure minimal deviation from the sampling strategy as determined.
Typically each soil sample will be between 0.2kg and 1kg depending on the characteristics of the soil such as homogeneity, presence of stones and other materials.
Consideration having been given to the nature of the rubble pile, samples will be taken from three depths at each sample location; the first sample will be a surface sample, followed by a sample taken from 500mm below the surface and another at 1m below the surface (where the depth is less than one meter only two samples are to be taken at that location). Samples taken at 500mm and 1m below the surface will be taken using an enclosed auger to ensure no sample material is lost or contaminated by other samples taken at various depths.
Background samples will be taken following a judgemental sampling pattern from areas where it is known that material from Barangaroo was not deposited to gain an accurate picture of existing soil contamination at the site. This information will be collated later with the data taken from the rubble pile in order to ascertain whether the site was contaminated prior to delivery of the soil from Barangaroo. In the event that this is the case, a additional detailed sampling program will be developed to determine the source of contamination.
The actual number of sample locations will be determined based on the knowledge of the site and the requirements of any regulatory body as well as the need to ensure a high confidence level. Further information regarding minimum number of samples is contained in Table E1 and Appendix F of AS4482.1 Guide to the investigation and sampling of sites with potentially contaminated soil Part 1: Non-volatile and semi-volatile compounds; table E1 relating to site characterisation and appendix F relating to determining the degree of contamination. The method outlined in Appendix F will be adopted for the purposes of the Port Kembla survey and the number of samples taken will be determined by this method.
All samples taken are subject to strict handling and storage procedures as outlined in AS4482.1 Guide to the investigation and sampling of sites with potentially contaminated soil Part 1: Non-volatile and semi-volatile compounds.
Following the soil sampling survey, a detailed report must be developed and include where relevant to the objectives of the survey (i.e. the status and distribution of contamination at the Port Kembla site):
the area surveyed;
the area that the report relates to;
identification of the site and survey limits with reference to GPS locations, easting's and northing's, distance from known datum points etc.;
photographs;
previous owners and usage;
recent activity;
site history;
local geography and geology;
sampling location map and method for sampling;
soil testing and methodology;
lab testing results;
recommended actions.
After the report is delivered and completion of the survey and assessment at Port Kembla a similar process, albeit suited to the particular site, would be implemented at Barangaroo. The objective of this survey and associated sampling strategies and lab assessment would be to prove within upper confidence limits that the soil form Barangaroo is not asbestos contaminated and can safely be delivered to Port Kembla.
Instructions for NATA lab assessment of samples
Where the samples are over 100g (in this case all soil samples will be above 200g), valid sub-sampling procedures that are fully documented should be applied so as to ensure that the sub-sample to be analysed accurately represents the sample received. As such the sample can be split into a smaller representative sample as in ISO 3082, BS EN 932-1 or BS 1337-1.
Homogenous pieces of suspected ACM must be visually identified under stereo microscope initially to determine extent of fibres within the material and layers and to separate fibres bundles or layers for further identification methods.
In order to unequivocally confirm that a sample contains asbestos the lab must utilise the method of polarised light microscopy (PLM) with dispersion staining. Fibres must be mounted on slides using various refractive index (RI) fluids and through this method, the type of asbestos may be identified.
It may be necessary to use a disintegration technique to free potential asbestos fibres from interfering organic fibres contained within the sample. The only methods permitted for this purpose are documented in AS4964:2004 Method for the qualitative identification of asbestos in bulk samples.
Dispersion staining is the only method for positively identification of the various types of asbestos contained with a sample and must include an assessment of morphological features of the sample as determined through polarised light microscopy as well as two or three methods from:
pleochroism;
optical orientation of the fibre axis;
optical extinction of the fibre axis;
strength of birefringence;
colour of the fibres.
Where asbestos is detected and when providing Lend Lease with the assessment results, the lab must fully document all procedures utilised to determine the type of asbestos in any given sample and include:
a description of the procedures used to identify the asbestos contained within the sample;
a description of the entire sample including weight and noting sub-samples where relevant;
a history of the sample including a description of the weight and size relative to the sample size so as to ensure the results can be correctly interpreted and for determining the extent of asbestos contamination;
procedures chosen for preparation of the sample.
Where asbestos is not detected in homogenous and non-homogenous samples further requirements for reporting are needed as outlined in AS4964. For non-homogenous samples the reporting limit of 0.1g/kg of sample material must be used unless indicated otherwise due to sample nature.
In the event that the homogenous suspected ACM pieces do not prove to be asbestos containing, non-homogenous soil samples will be taken to determine other asbestos contamination.
Soil samples will be subject to additional requirements for identification. The examination and subsequent classification of fibres from the sample shall be carried out as follows:
(a) If a significant quantity of the sample contains particle sizes that exceed 10 mm in dimension, screen the entire sample through a 10 mm sieve.
(b) Examine the >10 mm fraction by eye or magnifying glass.
(c) Separate out all fibrous matter as sub-samples for later examination by stereomicroscope and identification by PLM with dispersion staining.
(d) Screen the <10 mm fraction through a 2 mm sieve.
(e) Examine the <10, >2 mm fraction by magnifier and/or low power stereo-microscope.
(f) Separate out all fibrous matter from the <10, >2 mm fraction as sub-samples for later
examination.
Following sieving of the non-homogenous sample the techniques used to identify asbestos will be the same as those for homogenous samples under microscope, i.e. PLM with dispersion staining is to be used in accordance with AS4964.
Legislative requirements
In NSW the handling and storage of asbestos waste at worksites is regulated by WorkCover NSW under the WHS Regulation 2011. Once the waste is transported offsite as waste and deposited at waste receiving or other facilities it becomes regulated by the NSW EPA, now a separate legislative body to the NSW Office of Environment and Heritage (OEH) (previously Department of Environment and Climate Change and Water), and is managed according to several legislative instruments.
The transport, storage and disposal requirements for asbestos waste are contained within the Protection of the Environment Operations (Waste) Act 1997 and the Protection of the Environment Operations (Waste) Regulation 2005 (POEOWR).
The EPA is responsible for environmental regulation and associated activities throughout NSW and administers the Contaminated Land Management Act 1997 (NSW) for sites where asbestos contamination poses a risk significant enough to warrant regulation such as the Port Kembla and Barangaroo sites.
Contamination occurs under the Contaminated Land Management Act 1997 (NSW) where a substance that poses a risk to human health, is present in a concentration above the normal concentration that the substance would normally be present. Although asbestos presence does not necessarily mean a risk to human health, a risk will exist if the asbestos is disturbed and therefore any level of asbestos in the soil at Port Kembla over and above what the background levels are would be deemed to be contamination.
Under Section 60 of the NSW Act a person whose activities have led to the contamination of land, or the owner of contaminated land, must report the contamination to the EPA as soon as practicable after the person becomes aware of the contamination. There are significant fines up to $165,000 for corporations who fail to report contamination.
Under the associated Contaminated Land Management Regulation 2008 there are no specified levels of contamination for reporting, these are generally contained within guidance issued by the NSW Office of Environment and Heritage. The levels that trigger reporting requirements for contaminated land under section 60 of the NSW Act are contained within the Health Investigation Levels specified within the National Environment Protection (Assessment of Site Contamination) Measure 1999 (NEPM). Note: The NEPM does not actually specify a Health Investigation Level for asbestos.
In cases where the NEPM does not specify levels for a contaminant to be reported, the Guidelines on the duty to Report Contamination under the Contaminated Land Management Act 1997 state that "other reputable regulatory criteria may be used as a reference or alternatively a site specific risk assessment should be considered."
In NSW this means there is no definite stated levels of asbestos contamination of land that would be required to be reported to the EPA. The presence of asbestos on its own does not merit reporting to the EPA however given the fact that the asbestos presence at Port Kembla is "visible to the naked eye" and the emotional nature of asbestos contamination discovery and very high fines for not reporting, it would be advantageous to report any contamination found to the EPA as soon as practicable.
Once the EPA has been made aware of contamination, it must determine whether the contamination is severe enough to need regulation, which is determined on an ad-hoc basis under the criteria contained in section 12 of Contaminated Land Management Act 1997 (NSW):
"(a) whether the substances have already caused harm;
(b) whether the substances are toxic, persistent or bioaccumulative or are present in large quantities or high concentrations or occur in combinations;
(c) whether there are routes by which the substances may proceed from the source of the contamination to human beings or other aspects of the environment;
(d) whether the uses to which the land and land adjoining it are currently being put are such as to increase the risk of harm from the substances;
(e) whether the approved uses of the land and land adjoining it are such as to increase the risk of harm from the substances;
(f) whether the substances have migrated or are likely to migrate from the land (whether because of the nature of the substances or the nature of the land)."
According to the Act, the responsibility for risk assessment, sampling, monitoring, reporting and site remediation falls on the following people, in order of preference:
the person responsible for the contamination (i.e. Lend Lease);
the owner of the land (i.e. Port Kembla Port Authority);
the notional owner of the land (who is the mortgagee or has a vested interest in the land).
Revised regulatory requirements for managing asbestos waste commenced on 28 April 2008. These amendments were made under the Protection of the Environment Operations Amendment (Scheduled Activities and Waste) Regulation 2008, following significant consultation with industry and the broader community in 2007.
The following relevant requirements for asbestos waste are contained within the POEOWR:
• Waste must be stored on the premises in an environmentally safe manner.
• Bonded asbestos material must be securely packaged at all times.
• Friable asbestos material must be kept in a sealed container.
• Asbestos-contaminated soils must be wetted down.
• All asbestos waste must be transported in a covered, leak-proof vehicle.
• Asbestos waste must be disposed of at a landfill site that can lawfully receive this waste.
• It is illegal to dispose of asbestos waste in domestic garbage bins.
• It is also illegal to re-use, recycle or illegally dump asbestos products.
Local Council also have a regulatory role to play through the various planning and development policies where the risk posed by asbestos on development sites is not great enough to merit intervention by the EPA.
