Concentric Geoscience was retained to provide environmental consulting services for a heating oil release at a rural residential property outside of Brockville, Ontario. During the initial stages of assessment, it was determined that an unrelated, unused 5,000 litre heating oil underground storage tank (UST) was located adjacent to the release area. Concentric Geoscience tailored the assessment activities to ensure that petroleum contaminant impacts were appropriately characterized and attributed either to the insured loss or former heating oil UST in accordance with the insurance policy. The insureds subsequently retained Concentric Geoscience to complete assessment and reporting tasks relating to the removal of the UST, as required by the Technical Standards and Safety Authority (TSSA). Independent assessments and on-going monitoring resulted in two separate reports that were each reviewed and accepted by the TSSA.