Phase 1 Environmental Site Assessment vs Preliminary Site Investigation: What's the Difference?
If a Council, planner or property adviser has asked you to obtain a Phase 1 Environmental Site Assessment, you may also see terms such as:
Phase 1 ESA;
Stage 1 contamination assessment;
preliminary contamination assessment;
preliminary site assessment; or
Preliminary Site Investigation.
So are they different reports?
In NSW, they are generally referring to the same preliminary stage of contaminated land assessment.
However, the terminology currently used by the NSW Environment Protection Authority is Preliminary Site Investigation (PSI).
If we are preparing this type of report in NSW, Preliminary Site Investigation is the terminology we would ordinarily use.
For information about engaging Confluence Environmental to undertake one, see our Preliminary Site Investigation services in NSW.
Where Did the Different Terminology Come From?
The terminology around contaminated land assessment has changed and been used somewhat inconsistently over time.
Importantly, the former State Environmental Planning Policy No 55 – Remediation of Land (SEPP 55) did not establish “Phase 1 Environmental Site Assessment” as the formal name of the report.
The accompanying 1998 Managing Land Contamination: Planning Guidelines described the first investigation stage as:
Stage 1 – Preliminary Investigation.
Those guidelines described the preliminary investigation as an assessment of site history, site conditions and the potential for contamination, with the purpose of deciding whether more detailed investigation was required.
Likewise, the earlier NSW EPA Guidelines for Consultants Reporting on Contaminated Sites used the term:
Stage 1 – Preliminary Site Investigation.
Today, SEPP 55 has been replaced by Chapter 4 of State Environmental Planning Policy (Resilience and Hazards) 2021, but the preliminary investigation remains an important part of the contaminated land planning process.
What Does the NSW EPA Call It Today?
The current NSW EPA guideline is:
Consultants Reporting on Contaminated Land: Contaminated Land Guidelines (2020).
Within that guideline, the first reporting stage is clearly identified as:
Preliminary Site Investigation.
The guideline then separately identifies:
Sampling Analysis and Quality Plan;
Detailed Site Investigation;
Site-specific risk assessment;
Remedial Action Plan;
remediation and validation;
Environmental Management Plan; and
ongoing monitoring.
The current NSW contaminated land reporting framework therefore uses Preliminary Site Investigation (PSI) as the recognised report terminology.
Why Do Councils Still Ask for a "Phase 1"?
Because terminology has not always been used consistently.
Council policies, Development Control Plans, standard conditions and internal procedures may have been written at different times and may use terminology such as:
Phase 1 ESA
Phase 1 contamination assessment
Stage 1 investigation
or even combinations such as:
Phase 1 Preliminary Site Investigation.
For example, Inner West Council currently refers to a “Phase 1 Preliminary Site Investigation (PSI)” within its contaminated land development controls.
There are also numerous historical development applications and consultant reports in NSW that describe essentially the same preliminary assessment as a Phase 1 Environmental Site Assessment.
So if Council asks for a Phase 1 ESA, there is usually no need to commission a separate type of environmental assessment simply because the terminology is different.
If Council Asks for a Phase 1 ESA, What Should I Order?
In most circumstances, you should be seeking a Preliminary Site Investigation prepared in accordance with the current NSW contaminated land reporting framework.
The PSI should generally consider matters such as:
current and historical land use;
potentially contaminating activities;
surrounding land uses;
Areas of Environmental Concern;
Contaminants of Potential Concern;
geology and groundwater;
site conditions;
a preliminary Conceptual Site Model; and
whether further investigation is required.
The exact scope should still respond to the property and the reason Council has requested the assessment.
If Council has issued a specific request for information or development condition, it is worth providing that wording to your environmental consultant before the scope is prepared.
That allows the consultant to confirm what Council is actually asking for rather than relying solely on the terminology used in the request.
Is a Phase 1 ESA the Same as a Detailed Site Investigation?
No.
A Preliminary Site Investigation is intended to identify whether there is a credible contamination issue that requires further assessment.
A Detailed Site Investigation is generally undertaken where intrusive investigation is required to characterise contamination and resolve identified data gaps.
The fact that a Council document uses the term “Phase 1” does not change that distinction.
The important issue is the objective and scope of the investigation, rather than whether the document happens to call it a Phase 1 ESA, Stage 1 assessment or PSI.
What Should the Report Be Called?
For contaminated land work undertaken in NSW today, we recommend using:
Preliminary Site Investigation (PSI)
as the report title and terminology.
That aligns the report with the terminology used in the current NSW EPA Consultants Reporting on Contaminated Land guidelines.
Where a Council request specifically refers to a Phase 1 Environmental Site Assessment, the PSI can simply explain that it has been prepared in response to that requirement.
For example:
“This Preliminary Site Investigation has been prepared in response to Council's request for a Phase 1 Environmental Site Assessment.”
That removes any ambiguity while maintaining the current NSW reporting terminology.
Have You Been Asked for a Phase 1 Environmental Site Assessment?
If Council, a planner, purchaser or another project adviser has requested a Phase 1 ESA, Stage 1 contamination assessment or Preliminary Site Investigation, send us the request together with:
the property address;
proposed development;
Council correspondence;
relevant plans; and
any previous environmental reports.
We can review the requirement and confirm an appropriate scope.
Learn more about our Preliminary Site Investigation services in NSW or contact Confluence Environmental for a project-specific quote.