Suncor Energy Inc. - Certificate of property use

The director reviewed the comments and decided that some changes to the CPU were required to address these comments. The following outlines how the comments raised by the public are being addressed.

Both comments had raised the same two issues. The first issue was in regard to groundwater sampling on the Risk Assessment (RA) property. The public comment requested that periodic groundwater sampling should occur along the western and southern property boundaries of the RA property. The RA had concluded that any contaminants would biodegrade before reaching the southern and western property lines. The public comment wanted this assumption to be confirmed through groundwater monitoring along these property lines because it was concluded by the public commenter that if contaminants migrated off site from RA property in excess of site condition standards there would be an additional exposure pathway (groundwater vapours to indoor air) that potentially might cause an unacceptable risk of off-site receptors.

The director had reviewed the soil and groundwater data from the RA. It was considered unlikely that impacted groundwater would migrate to the western boundary since the RA had indicated that impacts were related to spills on the east side of the RA​​​​​​​ property in areas of former fuel infrastructure. The impacts were delineated and were centralized to the areas of release. Mobilization of impacted soils is unlikely as groundwater is typically deeper than the identified impacts. Two years after remediation of the RA​​​​​​​ property, impacts in groundwater have not been observed at or within 10 m of upgradient of the western RA​​​​​​​ property boundary or near the southern RA​​​​​​​ property boundary. It was concluded that a groundwater monitoring program along these RA​​​​​​​ property lines were not needed at this time.

The RA​​​​​​​ did include an evaluation of the risk to off-site receptors for both soil and groundwater and found the only off-site receptors identified being at risk might be utility workers due to the groundwater contamination near the eastern RA​​​​​​​ property line and localized soil contamination near the north-east corner of RA​​​​​​​ property and possible along the southern property line (south of TP25). Since there were no off-site buildings in these immediate areas, the soil vapour to indoor air was not a complete pathway for any off-site receptors.

The director considered the off-site evaluation in the RA​​​​​​​ and added the additional risk management measure from the RA​​​​​​​ to be included in the CPU​​​​​​​ (item 4.2 f). This item stipulates that the owner(s) of RA​​​​​​​ property shall inform the property owners of off-site areas (that were identified in the RA​​​​​​​) where there is a potential exceedance of the site condition standards that a health and safety plan may be applicable to utility workers or other workers if exposed to subsurface soils and groundwater.

The second issue in the public comment was related to adding the risk management measure that the owner informs the off-site property owners that a health and safety plan may be applicable to utility workers which was added to the CPU​​​​​​​ as described above.