What is an Environmental Site Assessment and When Do You Need One?
This blog post provides a summary of the purpose of an environmental site assessment (ESA) (or contaminated land assessment), what’s involved and why it’s essential for real estate transactions, development projects and regulatory compliance.
What is an environmental site assessment (ESA)?
An ESA is a study to determine if land is contaminated as per the definition in the Environment Protection Act 2017 (EP Act). Click on this link to our previous post “What is Potentially Contaminated Land” for a definition of contaminated land.
Environmental Site Assessment Process
Since 2015, all states have adopted a standardised, prescribed approach to the assessment of potentially contaminated land (PCL), known as the National Environment Protection (Assessment of site Contamination) Measure (ASC NEPM).
The purpose of the ASC NEPM is to establish a nationally consistent approach for the assessment of land contamination; to ensure sound environmental management practices by the community, including regulators, site assessors, site contamination consultants, environmental auditors, landowners, developers and industry parties.
Environmental site assessments are usually undertaken by a suitably qualified environmental consultant and in many cases proceed in multiple stages or phases due to site complexity and the discovery of unexpected contamination, or as funds become available.
The process to assess PCL can be broadly divided into two key steps (or phases), as follows:
#1 Preliminary Site Investigation
If a site is identified as PCL, the first stage is to decide if there is enough evidence to confirm if contamination is present, ideally, some indication of its extent and whether further investigation is needed. This will generally be satisfied by undertaking a desktop study known as a preliminary site investigation (PSI).
A PSI usually involves inspecting the site and establishing a site history to identify the characteristics of the site (such as the location and layout, buildings, the geological setting, current and past activities). It could also include a limited soil sampling program.
If a PSI shows a history of non-contaminating activities and there is no other evidence or suspicion of contamination, further investigation is not required.
#2 Detailed Site Investigation
A detailed site investigation (DSI) is necessary when a PSI indicates the presence of land contamination, i.e. the presence of unexpected underground structures (e.g. underground fuel or chemical storage tanks), the presence of imported fill (e.g. ash, odorous material or various types of refuse), soil staining or the detection of contaminants above background or screening levels and there is uncertainty about its risk potential or extent.
A DSI aims to delineate the type, levels, and extent of contamination to inform risk assessment and evaluate whether it precludes the continuation of existing or intended uses and, if necessary, provide the basis for developing an appropriate management or remediation strategy.
Conceptual Site Model (CSM)
One of the objectives of the ESA process is to develop what’s called a conceptual site model (CSM). The development of a CSM is an essential part of all ESAs and provides the framework for identifying how the site became contaminated and how potential receptors may be exposed to contamination either in the present or the future.
Where potential contaminants might exist the potential risk needs to be identified by means of the CSM. This should identify all the likely ‘source-pathway-receptor’ exposure routes. That is, for land to be impacted by contamination there must be:
- a source of contamination (for example, a substance in the land or groundwater);
- a pathway for the contamination to reach the receptor (for example, direct skin exposure/drinking of contaminated water), and
- a receptor that can be harmed (for example, a person’s health or fish in a waterway).
The initial CSM is constructed from the results of a PSI and is used to identify data gaps and inform a decision on whether a DSI is required.
Remediation
Sites found to present unacceptable risk to human health or to the environment must be managed or remediated (cleaned up). Whether the contaminated land will be managed or remediated and to what extent depends on the level of contamination and risks posed to human health and/or the environment. Risk assessment is also one aspect of making such a decision though other considerations such as practicality, timescale, effectiveness, cost, and durability also need to be considered.
Application
Within the planning system, change of use and redevelopment of land are the primary triggers to consider the potential for contamination. The EP Act and EP Regulations also establishes a range of duties, powers and functions (for persons in management or control of land) relating to circumstances where pollution or waste has already impacted land or groundwater, making it ‘contaminated’ for the purposes of the Act.
See below for a list of the main scenarios under which an ESA might be required. Click on this link to these previous blog posts “Contaminated Land and the Planning System” and “General Environmental Duty vs. Specific Environmental Duties: What’s the Difference?” for more information.
- Planning Scheme Amendment
- Planning Application
- Environmental Audit System
- Property Due Diligence
- Property Leasing
- Environmental Duties, i.e. the General Environmental Duty (GED) and the Duty to Manage.
Outcomes
Contaminated land can often be safely used and developed, provided any necessary controls to manage contamination are implemented.
The essential thing is to take a precautionary approach and understand the condition of the land (and all the possible cost and scheduling implications) at an early stage in the project lifecycle.
The ESA process is the main tool to feed into the decision making procedure.
Benefits
Nine out of ten times, potentially contaminated land is not an issue or represents a low-level risk that can be managed; however, is it worth taking the risk that it isn’t? Engaging a reputable environmental consultant will add value by actually saving you time and money in the long-run and help avoid any nasty pitfalls that could potentially bankrupt your business.
Next Steps
If you want more information on the subject of potentially contaminated land and how it might relate to your site, download our free guide ‘What Every Property Developer Needs to Know About Potentially Contaminated Land: the complete handbook’.
In here you will learn more about:
- What potentially contaminated land is and the associated risks to your business;
- What steps you need to take to mitigate potential risk and the entities you need to work with; and
- What the implications are from a cost and management perspective.
