Detailed Site Investigation (DSI) Phase II Environmental Site Assessment – Bilpin Petrol Station

Anderson Environmental Pty Ltd recently undertook a Contamination Assessment (Detailed Site Investigation – Phase II Environmental Site Assessment) under SEPP 55.  The work involved assessing the potential impacts of the previous use of the site in regard to potential contamination from the petrol station in relation to a proposed bakery being developed on the site.

DetailDetailed Site Investigation (DSI) Contamination Assessment

Whenever any site is purchased (or preferably before purchase) it is important to ensure it is fit for the purpose for which it is proposed to be used.  It is also important to ensure you are not purchasing a liability by purchasing a site with contamination and large clean-up costs.  Councils generally require a Preliminary Site Investigation (Stage 1 or Phase 1 Environmental Site Assessment) in the first instance.  This preliminary report is to determine the previous use of a site in relation to its potential risk in relation to soil and/or groundwater contamination or hazardous chemicals or materials which may be present.  This preliminary assessment provides a professional opinion in relation to the risk of contamination on the site and whether additional work in the form of a Detailed Site Investigation (often termed a Stage 2 or Phase 2 Environmental Site Assessment) is required.  A Detailed Site Investigation is to target potential contaminants and potential contamination based on the results of the Preliminary Site Investigation (PSI under SEPP55).  In this particular case the site had been used in the past as a Petrol Station with historic use dating back decades.  It has been quite a while since fuel was 49 cents per litre and the age of the pumps also provides evidence of the age of the previous use.  The Ampol sign reminds me of the “I’m as Australian as Ampol” advertising from the 1980’s and 1990’s.

Detailed Site Investigation (DSI) Contamination Assessment

Our work as Environmental and Geotechnical/Contamination Consultants takes us throughout NSW, Queensland and Victoria.  We get to see and undertake assessments on a broad range of sites.  We recommend obtaining a Preliminary Site Investigation before any site is purchased as once the site is purchased as the landowner you now own the contamination and clean up costs can be extremely expensive.

We utilise our own drilling equipment for most jobs and in some cases draw on our large number of associations with other drilling companies to undertake thorough and detailed assessments.  We have been asked for professional advice from the NSW EPA in the past and keep up to date with the latest legislative requirements and sampling techniques and equipment.

Please give us a call on 1300 302 507 for assistance with your next property purchase or project.

Site Remediation at Teralba

We were recently contacted, as we often are by a previous client to assist them with a Housing Development project which resulted in them saving approximately $450,000. They had a SEPP 55 Preliminary Site Investigation, a Detailed Site Investigation (DSI), and a Remedial Action Plan (RAP) undertaken by another company and were very concerned with the expected cost for the Contaminated Site Remediation which was in excess of $600,000. As the project was to supply a lower cost housing alternative for the less privileged the cost was of particular concern. Upon review of the documentation in the previous reports it became apparent that the site had not been characterised correctly in relation to the extent of the potential contamination along with its waste classification in relation to the leachate potential of the contaminant (in this case Lead). This resulted in an overestimation of the amount of material to be disposed of from the site and an incorrect waste classification of the material to disposed of which placed it in the highest waste category of Hazardous. These two factors resulted in the very high estimated cost for the site remediation.

Anderson Environmental undertook Geotechnical Drilling of the site with a combination of solid flight and direct push techniques to characterise the lateral and vertical extent of the contaminated material which was present. Laboratory analysis utilised the Toxicity Characteristic Leaching Procedure (TCLP) to determine the leachability of the contaminant. This test is to determine the Waste Classification of the material which resulted in it being classified as Restricted Solid Waste resulting in a much lower site remediation cost than Hazardous Waste.

With the accurate information from the Geotechnical Drilling and Site Characterisation along with the correct Waste Classification a Phase 2 Environmental Site Assessment (Detailed Site Investigation) report and Remedial Action Plan (RAP) was written. This resulted in less contaminated material to be disposed of at a lower waste classification rating thus significantly reducing the site remediation cost.

The client was extremely pleased with the project outcome and the saving of $450k which resulted in a huge cost saving for an extremely viable project outcome.

As Environmental Consultants servicing Sydney, Brisbane and Melbourne we have full time experience since 1992. We assist clients with providing services covering SEPP 55 (Preliminary and Detailed Site Investigations) Remedial Action Plans (RAP), on-site Remediation and Site Validation and Closure. We are often undertaking Risk Assessments for Pre-Purchase Inspections for clients before the purchase of development sites. Please give us a call or contact us via the “Contact Us” page of our website so we can address your specific project requirements.

Pre-Purchase Site Inspections for Ecological Risk

At Anderson Environmental we are often asked by our clients to provide advice early on in the development assessment process. Often this commences even before a client decides to purchase a property and it is generally the larger and more experienced property developers who know the value of getting a thorough  Due Diligence Pre-Purchase Inspection undertaken. Often we are advising client’s on properties in the millions and have recently advised a client on a 10 million dollar property before they decided to purchase. The viability of any project is critical to assess early on in the project planning process.

With the implementation of the new Biodiversity Conservation Act 2016 (BC Act 2016) there can be significant offset costs for offsetting the clearance of native vegetation and these costs are significantly higher than they have been previously. In certain cases where there are Critically Endangered Ecological Communities or Critical Habitat for Endangered Species there may be a Significant And Irreversible Impact (SAII) which cannot be offset thus leasing to a significant limitation for any development. In addition consideration must be given to if the site contains mapped areas of Outstanding Biodiversity Values.

So what is the role of a Pre-Purchase Ecological  Inspection ?

Most often a Due Diligence Pre-Purchase Inspection for potential Ecological issues can involve background searches and a scoping site inspection to identify any potential issues. Many clients however request a more detailed assessment of the site by way of a 5-part Test of Significance and/or Biodiversity Development Assessment Report (BDAR). These are more detailed reports which can form part of a Statement of Environmental Effects to support the development application.  The more detailed the assessment, the more accurate the information available for planning.

Project success starts very early on by determining whether a project is a “Go” or “No Go” and Due Diligence early on (often even before the purchase of the property) is critical in such a determination. It is important for working out risks and to provide a sound cost benefit analysis.

As experienced Environmental Consultants with experience since 1992 we assist our clients with a wide range of Ecological Assessments.

Why not give us a call on 1300 302 507 to discuss your next project.


Five-Part Tests of Significance


As of the 24th November 2019 the “Seven-Part Test Significance” will no longer exist. The new “Five-Part Test” of Significance” will be in place as of 24th of November 2019. The last of the Interim Designated areas will no longer apply and the Biodiversity Conservation Act (2016) will be the legislation applying to all Local Government Areas. It is important for clients to keep this in mind when they are preparing their development applications as there is a limited time to lodge under the old legislation. The last of the Interim Designated Areas are;

  • Camden;
  • City of Campbelltown;
  • City of Penrith;
  • City of Fairfield;
  • City of Hawkesbury;
  • City of LIverpool;
  • City of Wollondilly.

The final date for lodgement of all development applications in these Local Government Areas under the old legislation will be the 24th of November 2019.

As fully qualified and certified BAM Assessors we can assist you with your next project. Please give us a call on 1300 302 507 to discuss your project as careful planning is important early on in the project plan.