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Phase 1 Environmental Site Assessment


A Phase 1 environmental site assessment is used to identify past and present activities that have potential to cause contamination to a site. Also called a preliminary site investigation, they are typically requested by planning authorities for site rezoning or redevelopment as well as due diligence for property transactions.

Poor quality site contamination reports usually result in additional work and costs if they don’t meet regulatory guidelines. An incomplete Phase 1 environmental assessment can result in data gaps, opening potential for unexpected finds during site redevelopment. Geo-Logix has extensive experience in assessing contaminated sites and can help you manage environmental obligations to achieve the best possible outcome for your project.

Scope of Work

A Phase 1 site assessment involves a desktop study of past land uses together with a site inspection. The objective is to identify potential sources of contamination and the possible impact it may present to the environment or human health. A phase 1 environmental assessment includes an analysis of historical planning documents, land titles and aerial photos, and may also involve interviews with past and present land users. Occasionally, soil and/or groundwater samples are collected to give further insight on the impact of any potential contamination or to provide a foundation for a more detailed site investigation.

Cost of a Phase 1

The actual cost of a Phase 1 Environmental Site Assessment depends on a site’s location, features and complexity. The average cost is between $3,500 and $6,000. Anything cheaper than $3,500 is a strong indicator that critical checks or document reviews have been missed.

Next Steps

If a thorough Phase 1 environmental site assessment doesn’t reveal evidence of contaminating activities, further investigation is not required. However, where contaminating activities are suspected or known to have occurred, sampling is then undertaken as part of a detailed site investigation also known as a Phase 2 Environmental Site Assessment.

Conceptual Site Model

A conceptual site model (CSM) shows the links between sources of contamination and any receptors. A CSM is site specific and an important step in guiding a sampling analysis plan for the detailed site investigation stage.