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 Environmental
Site Assessment
What is an ESA?
The phrase 'Environmental Site Assessment' (ESA) has come to mean the
formal evaluation of an area of land with respect to environmental contamination
- and specifically to the chemical contamination of soil and groundwater.
This evaluation may include an assessment of the potential impact of contaminant
migration from the investigated area to adjacent areas, surrounding air,
surface water and groundwater resources.
When is an ESA required?
Frequently, an ESA is commissioned when contamination of a site has
become all too obvious, and the main questions asked are: 'Is it feasible
to clean up this site, and how much will it cost?'
ESAs are also commonly carried out as a routine procedure, however.
For example, an ESA is often commissioned in one of the following circumstances:
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As a pre-acquisition or pre-sale assessment, on behalf
of either purchaser or vendor, when a property is being sold. Such
assessments can be considered analogous to the title and planning
searches carried out as a routine part of the conveyancing process.
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As a pre-development assessment, when a property is
to be redeveloped or is to have its usage changed - for example, from
a factory to a residential subdivision.
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As a pre-development assessment of a greenfield site,
to establish baseline conditions and assess environmental, geological
and hydrological constraints to development. An example would be an
assessment of waste disposal constraints on rural subdivisions.
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As an audit of the environmental effects of an ongoing
operation, to ensure sound environmental practice and regulatory compliance.
Who may require an ESA?
Anyone involved in land transactions should consider the benefits of
an ESA. Anyone buying or selling land should consider the possibility
that it may be contaminated. The financial risks are significant.
Vendors may be liable for misleading statements made to potential purchasers;
owners or lenders may be liable for the activities of occupiers. Although
the financial risks associated with land contamination cannot be eliminated,
they can be managed, and one of the best management tools available
is the Environmental Site Assessment.
Many organisations, including lending institutions, banks and finance
houses (particularly those who have previously been exposed to environmental
liability in the USA), now routinely commission ESAs for all major land
purchases.
Planning authorities (generally local councils) require an environmental
assessment to be completed before considering rezoning applications
that seek approval for a more sensitive land use. For example, a developer
might intend to put a housing estate on land that was once occupied
by factories.
Who should undertake your ESA?
Your ESA should be undertaken by a skilled and experienced specialist,
who understands the risks involved, and who can clearly communicate
the results to you. It is important that the appropriate experience
extends beyond the directors in the office - to the professional staff
who will actually see your site.
What CMJA can offer you
CMJA has completed over 300 ESAs, ranging from assessments for property
transfer of small blocks of land, to three of the largest such assessments
undertaken in Australia. We offer a personal service that includes a
site reconnaissance undertaken by senior professionals, modern instrumentation,
quality assurance/quality control procedures to international standards,
analysis in NATA-registered laboratories, and a very high standard of
reporting.
What is involved?
We prefer to undertake ESAs as staged studies, comprising up to three
stages.
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Stage 1A
Stage 1A typically involves a review of the site's history, and
includes the following work.
- We assess available topographical and geological mapping,
and current and historical aerial photographs.
- We review relevant published geological, geotechnical and
hydrogeological information.
- We compile information about the site's ownership history,
and the nature of activities previously undertaken on the site.
- We interview the current and, where possible, the previous
owners and occupiers of the site, to assess environmental management
practices, and to identify the location of particular activities
on the site.
- We review the site's development and regulatory history, with
particular attention to development applications, discharge
licences, compliance notices and orders imposed under the Contaminated
Land Management Act (1997) and Protection of the Environment
(Operations) Act (1997), and under previous legislation such
as the Environmentally Hazardous Chemicals Act (1985), the Public
Health Act (1991) and the Unhealthy Building Land Act (1990).
- We assess the status of adjacent land, and its potential impact
on the site.
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Stage 1B
Stage 1B is usually undertaken concurrently with Stage 1A, and
involves a site reconnaissance by an experienced assessor. This
comprises a walk-over and visual observations, supplemented with
photography and on-site instrumental measurements.
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Stage 2
Stage 2 is carried out only if warranted by the results of Stage
1. Investigations involve sampling and analysis of site materials
in order to establish levels of contamination. Stage 1 results
will dictate to a large extent, the specifics of Stage 2: the
number of samples, their location, their depths and the recommended
analytical suites.
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Stage 3
The final stage of the process involves the preparation of a Remedial
Action Plan (RAP) summarising the investigations undertaken for
the site, and providing recommendations and a detailed remedial
action plan for site clean-up.
We believe that this staged approach to ESAs is the most effective,
and offers better value for money. We keep our clients informed
at each stage, and we provide an assessment completed to high
technical standards.
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Some interesting ESAs that we have been involved with are outlined
below.
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Contaminated Site Assessment, Bimbimbie, South Coast, NSW
The Eurobodalla Shire Council, asked us to assess possible contamination
of land earmarked for a fire-training complex. The site was formerly
part of a timber treatment impregnation facility that operated
for some 23 years. Possible contaminants of concern included copper,
chromium, and arsenic (CCA) salts, oil-based creosote, total petroleum
hydrocarbons (TPH), and polycyclic aromatic hydrocarbons (PAH).
CMJA conducted a detailed background site study. We reviewed
historical records, interviewed long-term staff, and reviewed
geological and topographic mapping, aerial photography and other
relevant data. On-site fieldwork included assessment of the potential
for dust generation and ground disturbance during construction
and ongoing use of the site, in conjunction with the collection
and analysis of approximately 30 soil, sediment and water samples.
On the basis of the review of historical and background data,
and the on-site fieldwork, CMJA concluded that the land was suitable
for use as a fire-training complex.
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Former Ferrous Foundry, Green Square Gardens
CMJA was commissioned to undertake an ESA of an inner-city property
that had been used as a ferrous foundry. Investigations at the
property had identified several areas of concern, on both the
site and the adjacent property, including the migration of diesel
and solvents from a number of underground storage tanks that had
been in use during the site's 60-year history. The site and adjacent
property had been significantly impacted by TPH and PAH contaminants,
which had migrated within the shallow water table evident in the
area.
After the investigation, CMJA developed and implemented a remedial
action plan for the site, involving the excavation, classification
and off-site disposal of up to 13,000 tonnes of material impacted
by lead, TPH and PAH. Further material was left in situ following
discussions with the Auditor appointed for the site. This remediation
has now been successfully completed, and a Site Audit Statement
issued.
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Environmental Site Assessment, Tahmoor, Southern Highlands,
NSW
Precision Planning commissioned us to assess the potential for
soil and/or groundwater contamination at a site in Tahmoor, previously
occupied by a service station. This information was to assist
with a development application for a new shopping centre facility.
Stage 1 of the investigation comprised a review of historical
and relevant site information, and a site visit. During the site
visit selected soil samples were screened for volatile organic
compounds (VOC), and some selective excavation was carried out
to assess where contamination was likely to have occurred. We
identified the strong likelihood of contamination on the site
given its previous usage as a fuel service station. Stage 2 works
were therefore conducted to investigate potential sub-surface
and groundwater contamination at the site. Soil samples were collected
and analysed as recommended by the NSW EPA's Guidelines for Assessing
Service Station Sites (1994).
The investigation found that much of the soil on site was contaminated
with TPH and benzene, toluene, ethylbenzene and xylenes (BTEX),
but that the limited extent of contamination made it possible
to excavate and dispose of the soil in appropriate landfills.
Soils in those areas found to be more highly contaminated were
recommended for bio-remediation by on-site landfarming techniques
prior to disposal at suitable landfills. These recommendations
have since been implemented by the developers, and the site successfully
transformed into a shopping centre.
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Capability
Statements 