Designated Substances and Hazardous Materials Survey / Abatement Closure Report

In 2013, XCG conducted a Designated Substances and Hazardous Materials Survey (DSHMS) at a vacant school that was constructed in1 927. The DSHMS was requested prior to beginning significant renovations in the building. A total of 82 bulk building materials were submitted for laboratory analysis of asbestos, 28 paint samples were submitted for lead analysis, and three bulk building material samples were submitted for mould analysis. Pipe elbow parge cement, wall plaster, drywall joint compound, and vinyl floor tiles throughout the building, peach cove base leading to the basement, and silver paint in the boiler room were confirmed to contain asbestos. Twenty-six of the 28 paint samples had lead concentrations greater than 90 mg/kg [parts per million (ppm)] and were determined to be lead-containing. Visible mould was identified on walls in the sub-basement and on the pipe wrap in the basement hallway. Severely water damaged building materials were also identified in the sub-basement. Water damaged ceiling tiles were also observed on the first floor.


The laboratory results indicated that Stachybotrys sp. and Chaetomium sp. growth and spores were detected in the sub-basement and heavy Penicillium sp. and Cladosporium sp. growth was detected on the pipe wrap in the basement hallway. As part of the DSHMS, light ballasts were inspected for PCBs, thermostats were inspected for mercury content, and other Designated Substances were not identified to be present within the building.


Approximately a year and a half later, XCG was retained by a different client to conduct inspections of the mould and asbestos abatement activities and to conduct post-abatement clearance air sampling and testing. Abatement activities were completed by a licensed abatement contractor in general accordance with Type 3 operations for asbestos abatement and Level 3 guidelines for mould abatement, with the entire building being treated as the containment area. XCG was on-site to inspect the contractor’s set-up prior to the commencement of the abatement activities and conducted weekly visits to inspect the contractor’s set-up and to monitor abatement progress. Following the completion of abatement activities, XCG inspected the completed work area for compliance with the scope of work. If observed, minor deficiencies were verbally communicated with the abatement contractor, and significant deficiencies were communicated in writing to the abatement contractor. The weekly site visits were conducted randomly and without prior warning to minimize the possibility of the abatement contractor knowing the site visit schedule and allowing correction of deficiencies to lag.


Following final completion of abatement activities, XCG conducted clearance air sampling with analytical results being compared against the Occupational Health and Safety Act (OHSA) Ontario Regulation (O. Reg.) 278/05 criterion of 0.01 fibres per cubic centimetre (f/cc) for asbestos fibres, and a comparison of indoor sample results against outdoor sample results for mould. The air sampling locations were selected to be representative of asbestos-in-air and mould-in-air concentrations inside and outside the building. Asbestos clearance air samples were collected using recognized air monitoring techniques for asbestos following a Type 3 abatement, including the use of forced air before and during sampling to dislodge, and keep asbestos fibres suspended throughout sampling. Two background or control mould-in-air samples for comparison purposes were collected outside the building, one before and one after the interior samples were collected.


Based on XCG’s observations, the ACMs and mould noted above were removed in accordance with acceptable industry practices and requirements. The asbestos clearance air sample results were all less than the laboratory detection limit of 0.001 f/cc of air and less than the O. Reg. 278/05 criteria of 0.01 f/cc. The mould clearance air sample results indicated the mould groups and concentrations observed from the indoor samples were not significantly different from the outdoor samples. Based on the asbestos and mould clearance air sample results the asbestos and mould abatement activities were successful.