Key Elements of a Phase III Environmental Site Assessment

A little while ago, we gave you a summary of Phase I and Phase II environmental site assessments. Put simply, Phase I Environmental Site Assessments involve in-depth document research and review, as well as a detailed site visit to evaluate the potential for contamination, and what impact said contamination may have on the environment if present.

Phase II may follow Phase I if any evidence is found of possible contamination. If this is the case, then an ‘intrusive’ investigation is initiated which tests a variety of things for contaminants and concrete proof of contamination. If proof of contamination is found – and it is deemed hazardous – then remediation is needed, and phase III will commence. Today, we’ll give you an overview of what exactly Phase III environmental site assessments are and what is involved in their execution.

What is it?

Phase III environmental site assessments are carried out when phase II finds conclusive evidence of contaminants. Phase III is the estimation of the impact that the contaminants have on the site as well as how to deal with remedying the site. The impact of the contaminants will vary depending on what they are and the volume of them that are found.

Certain operations will be set in motion in an effort to remedy the site and clear it of all contaminants. This process can take anywhere from a single day to multiple years – depending on the type of contamination that is found and the risks it poses. A final report will then be written up and presented to you with all the information on what has transpired.

What are the factors to consider?

Cost, timelines, regulations and limitations are all key factors in determining what is the appropriate strategy for site remediation. The client’s goals for the site are also considered, as this will impact action going forward. Depending on the type of contamination, the clearance of the contaminants may only take a day. This can be the case if the soil is contaminated and all that is required is a standard soil excavation and disposal operation.

Other operations may take longer to complete and should be factored into your own schedule for the site’s development. It is recommended that you always go ahead with a phase III assessment when one is recommended to you by an environmental inspector as if one is recommended, then it means that there is conclusive evidence that there are contaminants on your site.

What are my options?

There are several strategies that can be used in order to make the site to meet regulatory requirements again. For less complex remediation processes, such as excavation and disposal of contaminated soils, the time required is much less and can be carried out in as little as a day – as mentioned in the above section.

However, sometimes longer remediation processes are needed, due to the characteristics of the site, or for more complex contamination issues. Strategies such as chemical oxidation and bioremediation can take months or years. You might think this is a long time, but at the end of the day, it’s much safer and smarter to put in the effort and time now to ensure that everything is safe, rather than deal with a potential problem that could come up later down the track.

In some cases, it has been found that it is actually safer to leave the contaminants in place and seek to remedy the site in other ways – without removing the contaminants. This is because, in some cases, it can actually be more dangerous to remove the hazardous contaminants, as doing so could release them and cause further hazards for the environment and the people.

As we’ve mentioned, phase III environmental site assessments are only necessary if the environmental inspector has deemed it to be, based on their findings in phase II. You are not required to get a phase III assessment.


After the developed plan has been executed and the site is remedied as much as possible, the final phase will be complete. This is where the report and documentation will be created stating the processes and operations that were undertaken to reach the outcome. As we mentioned earlier, environmental site assessments can drastically vary depending on a variety of factors. So, it’s important to be patient when your site is being assessed.

Looking for a phase III environmental site assessment?

Environmental site assessments are key to ensuring your work site is safe to work on and inhabit. A phase III site assessment is the final phase when it comes to environmental sites assessments and is designed to remedy the worksite completely – or at least as much as is safely possible – of hazardous contaminants.

If your site is in need of a phase III assessment, then why not consider the expert work of Alpha Environmental? Our highly trained and qualified environmental consultants are specially trained to inspect and undertake site assessments in an efficient and professional manner.

We’ve had extensive experience with worksite inspections and developing the best plans of action when it comes to remedying the sites. We’re also qualified to undertake a variety of other environmental services including groundwater testing and refurbishment/demolishment.

If you would like to discuss the possibility of having a phase III environmental site assessment conducted on your site, then please give us a call on 1300 039 181. Alternatively, you can fill out the contact form on our website and we will get back to you to discuss your requirements.