Key Elements of Phase I Environmental Site Assessments

Environmental site assessments are necessary procedures for many new businesses. Their prime directive is to ensure the site is environmentally sound and safe for employees to work on and for others to be around. An environmental site assessment involves studying the past and present onsite activities to determine the likelihood of contamination, and – if present – what effects said contamination could have on the surrounding environment. These site assessments are broken up into three phases. In this blog, we outline the scope of Phase I environmental site assessments to give you a better understanding of what they involve.


Site visit

The first thing involved in a phase I site assessment is a visit to the site itself by a professionally trained inspector. This involves a physical inspection where they’ll determine and – if necessary – catalogue the presence of hazardous materials or petroleum products. This is also a great chance to learn about the process as you will be able to see the inspection be conducted first-hand and raise any questions you may have. This includes examination for potential:

  • Soil contamination;
  • Groundwater quality and depth;
  • Surface water quality;
  • Chemical spill residue;
  • Vegetation dieback; and
  • Evaluation of any likely environmentally hazardous site history.

Neighbouring properties will also be assessed during the site visit. This is because some hazardous materials from your site could’ve leaked over to adjacent properties or vice versa. This is to ensure the assessment is as thorough as possible and all bases are covered. Remember, a phase I site assessment doesn’t actually involve any form of testing – that comes in phase II if it is deemed necessary.


Historical research/review of records

Historical research covers the examination of all historical records pertaining to the site, including:

  • Historical Aerial Photographs
  • Reverse Street Directories
  • Building Permits
  • Planning Records
  • Topographical Maps
  • Fire Department Information
  • Water Department Information
  • Tax Documents
  • Title Information

This in-depth investigation is paramount to the phase I assessment process. The research is evaluated by the inspectors and used to determine whether or not the current state of the site is hazardous – or if there’s something in site’s past that could’ve left lingering hazardous materials on the site. A site can turn up anywhere from a dozen to a thousand different types of records and documents. This depends on a myriad of varying factors such as how old the building is, how many owners has it had and if any renovations have occurred – to name a few.

There are certain operations that site assessment specialists look out for when reviewing documents. For example, if the site was used as a petrol station then there is a chance of petroleum contamination. If the site was once used as a printing or manufacturing plant, then there is a chance that the residue from certain heavy machinery and chemicals used may still be lingering around the site in one form or another.

It is these types of historical moments in the site’s lineage that raise red flags to the inspectors. If any of these are found, then it will prompt further investigation into the matter with a renewed concentration on the specific matter of concern. This is closely linked with the next step – especially if something suspicious is found in previous



This step is still executed even if no flags are raised during the investigation into past documentation and records. The interviews are conducted with the intent of gathering as much information as possible. There may be certain things that were not documented on paper in some cases and so the interviewing process is a great way to dive further into the site’s history. Some of the types of people that are typically interviewed are:

  • Previous tenants;
  • Fire department personnel;
  • Relevant government departments – such as local health, departments, fire departments and water departments; and
  • Relevant petroleum companies.

Talking to people face-to-face can also be a much more informative and enlightening experience. Some of the interviewees may not know anything about the sites environmental status and others may know a great deal. This is typically done after the documentation reviewing stage as if something is found whilst looking at old documents and records, then it can be raised with the appropriate people during the interviews.



The final step of phase I environmental site assessments is the report that is prepared for you. The inspectors will compile all the relevant information that their study has revealed and present it to you. This report will be highly detailed and also outline the key findings from the assessment.

A conclusion will be made and presented in the report also – as well as if you’ll need a phase II site assessment. It is important to note however that phase II environmental site assessments are generally only needed if there is a significant amount of environmental contamination present.


Are you in need a phase I environmental site assessment?

Environmental Site Assessments play an important part in determining the safety of a particular site, especially when there are strict OH&S policies to be considered. That’s why at Alpha Environmental, our expert environmental specialists are experienced and fully trained in all phases of environmental site assessment and remediation.

 If you would like to know more about getting a phase I environmental site assessment done for your site – or you would simply like to know more about some of the other services that we offer – then please get in touch with us by calling 1300 039 181. Alternatively, you can fill out the form on our website so that we can provide you with a solution tailored to your specific requirements.