Environmental Site Assessments (ESA)

Important steps to Managing
Your Environmental Liability

An Environmental Site Assessment (ESA) is a critical step in determining the environmental condition of your site. You may be considering an ESA for a number of reasons: to support a bank financing application, property transaction, or Record of Site Condition Application as you plan to change your property’s use. ESAs must conform to specific standards (CSA and ASTM). For properties in Ontario, ESAs must meet the requirements of Ontario Regulation 153/04 which state that the ESA must be completed by a Qualified Person (QP – generally a Professional Engineer or Professional Geologist with special registration). C.L.E.A.N.’s service providers are made up of experienced teams of professionals who can help you complete the appropriate ESA for your needs.

Phase I ESA

Phase I ESAs include a non-intrusive investigation to understanding the environmental history at a site. C.L.E.A.N.’s service providers comprehensive approach, supplemented by several years of engineering experience, includes analysis of detailed aerial photographs and mapping, historical process audits, and detailed records searches. C.L.E.A.N.’s service providers are made up of senior engineers, are Qualified Persons (QPs), and oversee all project work. Based on our analysis of available records for the site, our experienced service providers decide on next actions. If the Phase I ESA searches reveal a cause for further investigation, the service providers develop a list of Areas of Potential Environmental Concern (APECs) for the site.

The APECs identified in the Phase I ESA can lead the QP to recommend a Phase II ESA to explore APECs.

Phase II ESA

The Phase II ESA is guided by the information uncovered in the Phase I ESA, that is, the APECs.

Whereas the Phase I ESA was a non-intrusive review of site conditions, the goal of the Phase II ESA is to collect soil and groundwater samples from the areas identified to determine whether contamination is present and if so, to what extent.

C.L.E.A.N.’s Phase II ESA investigations are focused by the owner’s goals for the site in mind. C.L.E.A.N. service providers consider future planned site uses as this dictates which criteria and sampling results are compared to.

C.L.E.A.N.’s service providers have proprietary sampling protocols, using on-site testing, improve sample quality while allowing us to complete work in a shorter time frame. This translates to more certainty in understanding your site, allowing you to make informed decisions to save time and money.


If the Phase II ESA confirms contamination, a Phase III ESA may be required. A Phase III ESA is the phase at which remedial work occurs to address contamination.

Remediation can include the cleanup of known contamination based on the appropriate criteria as determined by our experts. C.L.E.A.N.’s service providers remedial plans address potential issues relating to health and safety, environmental concerns, groundwater control, excavation and building support, remedial technologies and soil management.

Record of Site Condition (RSC)

A Record of Site Condition (RSC) is a summary of environmental work done at a site under O.Reg. 153. RSCs are filed with the Ministry of the Environment and Climate Change (MOECC) and are kept as a public record. An RSC provides a consistent way to communicate that the appropriate standard of work has been completed and that historic contamination is now addressed at the site.

RSCs may be required to redevelop land in order to change the land use.

Contact us so that we can provide you with
a needs analysis for your project.