Preliminary and Detailed Site Investigations

Introduction

At EnviroX Consulting we understand the critical importance of thorough site investigations in ensuring environmental safety and regulatory compliance. Our expertise in Preliminary Site Investigations (PSIs) and Detailed Site Investigations (DSIs) enables us to provide comprehensive assessments that inform project development and mitigate potential environmental risks.

If you plan to build, excavate, demolish, or dismantle a site in NSW, assessing the risk of on-site contamination is a crucial first step. For this reason, most local Councils now require a Preliminary Site Investigation (PSI) report before approving a Development Application (DA)

Hazardous substances such as asbestos and lead can be present in groundwater, surface water, soil, air, and existing structures, posing significant health risks and affecting the land’s financial viability. Without a comprehensive report confirming acceptable contamination levels, your project may face legal and regulatory consequences. Additionally, if you’re purchasing land, a PSI can identify contaminants that could diminish its value.

Preliminary Site Investigations (PSIs)

What is a Preliminary Site Investigation?

A Preliminary Site Investigation is the initial phase of assessing a site’s environmental conditions and potential contamination. This process integrates desktop research with on-site inspections to identify past land uses, possible contamination sources, and environmental risks. By evaluating the site’s history and existing conditions, PSIs assist in making informed decisions about future site use and for determining whether more detailed investigations are necessary.

Benefits of PSIs

• Cost-Effective: Identifying potential issues early can save time and resources in the long run.
• Regulatory Compliance: Ensures adherence to local and national environmental regulations.
• Informed Decision-Making: Provides a foundation for further investigations or project development.

Key Components of a Preliminary Site Investigation (PSI)

1. Desktop Study
   The PSI begins with an in-depth desktop study, where existing site information is gathered and analysed. This includes historical land use records, zoning documents, aerial imagery, and previous environmental reports. The objective is to identify potential contamination sources, contaminants of concern, and areas that may be affected.
2. Site Inspection and Sampling (Optional)
   Following the desktop study, our experienced consultants may need to conduct on-site assessments with visual inspections and sampling to identify extent of contamination. A field screening will likely be conducted with potential of sampling. We take soil, water, and/or air samples from strategic locations on the site to analyse in accredited laboratories. Samples are taken to measure the type of contaminant and its extent within the site that may pose risks to health or the environment.
3. Report Preparation
   A detailed PSI report is then compiled, summarising the findings from both the desktop study and sampling. It identifies the contaminants and hazards if present, evaluating both the likelihood of exposure and the potential severity of impact on human health and the environment. This helps our clients make informed decisions about site remediation, mitigation strategies, or regulatory compliance.

When Do You Need a Preliminary Site Investigation (PSI) in NSW?

In New South Wales (NSW), Australia, a Preliminary Site Investigation (PSI) is required under various circumstances, particularly when there is a potential risk of land contamination. Below are key situations when a PSI may be needed:

1. Development Applications (DAs) & Planning Permits

• Many local councils in NSW require a PSI as part of a Development Application (DA), especially if the site has a history of potentially contaminating activities.
• This aligns with State Environmental Planning Policy (SEPP) – Contaminated Land Management 2021, which mandates that councils consider land contamination risks before approving developments.

2. Change of Land Use

• A PSI is mandatory if you are proposing to change land use from industrial or commercial to residential, childcare, or other sensitive uses.
• Under the NSW Contaminated Land Management Act 1997, sites must be deemed safe for the intended use.

3. Buying or Selling Property (Due Diligence & Finance Approval)

• Lenders and financial institutions often require a PSI before approving loans for property transactions.
• Buyers may conduct a PSI to identify contamination risks before purchasing land.

4. Before Excavation, Demolition, or Redevelopment

• Required when carrying out earthworks, demolition, or excavation to assess contamination risks in soil and groundwater.
• Ensures compliance with NSW Work Health and Safety (WHS) regulations and EPA guidelines.

5. EPA Requirements & Environmental Compliance

• If the NSW Environment Protection Authority (EPA) suspects land contamination, they may require a PSI.
• If contamination is found, a Detailed Site Investigation (DSI) may be required to assess the extent of contamination.

6. Lease Agreements & Liability Protection

• A PSI is often conducted to document baseline contamination conditions before leasing or selling land.
• Helps property owners and tenants avoid future liability disputes over contamination.

Phases of Environmental Site Assessment

1. Preliminary Site Investigation (PSI) – Phase 1 Environmental Site Assessment
   The first step in evaluating a site’s contamination potential. It involves a desktop study, site inspection, and development of a Conceptual Site Model (CSM) to identify possible contamination sources, pathways, and receptors. The PSI determines whether further investigation is required.
2. Detailed Site Investigation (DSI) – Phase 2 Environmental Site Assessment
   If contamination is suspected or confirmed during the PSI, a DSI is conducted. This phase includes soil, groundwater, surface water, and air sampling to assess contamination levels. The data collected helps determine the extent, type, and impact of contaminants.
3. Remedial Action Plan (RAP) – Phase 3 Remediation of Contaminated Sites
   If contamination poses a risk to human health or the environment, a RAP is developed. This plan outlines remediation strategies, including site cleanup, containment, or risk mitigation measures, ensuring compliance with regulatory requirements.
4. Validation and site monitoring reports – Phase 4 Validation and ongoing site monitoring reporting After remediation, this phase ensures the site meets cleanup objectives and is safe for its intended use. It involves additional sampling and analysis to confirm contamination levels are within regulatory standards. Ongoing monitoring may be required to track the long-term effectiveness of remediation efforts and detect potential re-contamination. The results are documented in detailed reports that provide assurance of the site’s safety and compliance with environmental regulations.

Detailed Site Investigations (DSIs)

What is a Detailed Site Investigation?

A Detailed Site Investigation delves deeper into the environmental conditions identified in the PSI. This phase is crucial for understanding the extent and severity of contamination and for developing appropriate remediation strategies.

Our DSI Services

• • Comprehensive Sampling: We conduct extensive sampling of soil and / or ground and surface water to delineate the extent of contamination.
  • Detailed Risk Assessment: We perform thorough risk assessments to evaluate the impact of contaminants on human health and the environment.
  • Remediation Planning: Based on our findings, we develop tailored remediation plans to address identified hazards effectively.

Benefits of DSIs

• • Thorough Understanding: Provides a comprehensive understanding of site conditions, enabling effective risk management.
  • Regulatory Support: Assists in obtaining necessary permits and approvals for site development or remediation.
  • Mitigation Strategies: Helps clients develop informed strategies to mitigate environmental impacts and ensure compliance.

Why Choose Us?

• • Expert Team: Our consultants are highly trained and experienced in environmental assessments and compliance.
  • Cutting-Edge Technology: We utilise the latest technologies and methodologies to ensure accurate and reliable results.
  • Client-Focused Approach: We work closely with our clients to understand their specific needs and provide tailored solutions.