Environmental and Regulatory Considerations Involved in a Site Change of Use
A company would like to open an early childhood centre on a commercial property previously occupied by an automotive repair shop and gasoline service station. All the fuel installations were removed at the time of the garage’s closing. The site history establishing these previous activities was made possible by a Phase I Environmental Site Assessment conducted by Terrapex. The site plan, dated 1960 and received in response to a Freedom of Information request, revealed the presence of fuel, heating oil and spent oil storage tanks, a separator, hydraulic cylinders and an island of gasoline pumps. Consultation of this plan as well as aerial photographs unearthed the existence of several generations of buildings on the site. The location and configuration of these buildings varied depending on the year of the consulted documents. Consequently, potential contamination risks associated with the aforementioned equipment (storage tanks, cylinders, etc.) and backfill were raised. A Phase II Environmental Site Assessment was therefore recommended to address the risks and attest to soil and groundwater quality.
This case study involves a site change of use because the termination of fuel-dispensing operations occurred before Section IV of the Environment Quality Act (EQA) came into effect in 2003. The criteria to be met are therefore those corresponding to the intended site use. Accordingly, sensitive institutional site use such as an early childhood centre require compliance with Land Protection and Rehabilitation Regulation (LPRR) Schedule I limit values.
The initial mandate of the Phase II Environmental Site Assessment sought to establish whether the at-risk areas defined in the Phase I ESA presented concentrations exceeding Schedule I limit values. Following the field work, soil that did not comply with these limit values was noted in one of the indoor boreholes, and ethylene glycol concentrations were observed in wells upgradient of the site. A complementary Phase II ESA comprising four additional boreholes was required to delineate this contaminated soil enclave, and the groundwater was assessed a second time to validate the previous results.
A contaminated zone was then established during the complementary field work. In addition, soil presenting metals (Ni) concentrations exceeding Schedule I values was identified. Some Québec regions have naturally elevated background nickel levels; although this issue is known and documented by the MELCCFP, the Ministry still requires evidence that this is indeed the case as outlined in Section 2 of the Evaluation Guidelines of Natural Background Levels in Soil.
In the end, despite the delays associated with complementary fieldwork, the demonstration of natural background levels and legal obligations, the property can now be remediated in order to make the client’s project a reality. The key element in this case study was certainly the Terrapex teamwork which ensured clear and concise communication with the client, a detailed explanation of procedures and appropriate cost control respecting the client’s needs.