CASE STUDIES / In Situ Remediation of a Fuel Oil Spill


An insurance company commissioned CM3 to assess the contamination and provide remediation consulting following a 550-litre fuel oil spill in a bedrock aquifer that supplied multiple wells in a small town in Ontario.

This project demonstrates our ability to complete in situ assessment and remediation in complex hydrogeological conditions while acting quickly and offering solutions that satisfied multiple stakeholders.

In situ assessment and remediation in complex hydrogeological conditions to satisfy multiple stakeholders

The depth of contamination and the presence of buildings near the spill precluded excavation and offsite disposal, which is the most cost-effective solution. Instead, we recommended in situ remediation, which, though costly and time-consuming, was effective and discrete enough in this case to allow ongoing use of the property during remediation.

In the first month of the project we delineated the extent of impact on the potable bedrock water table, then advised on the best way to protect the local water supply during cleanup.

Next we oversaw the design, operation, and optimization of an in situ remediation system. The system used liquid petroleum hydrocarbon (LPH) recovery by total fluids pumping as an initial corrective action, then bioslurping followed by oxygenation techniques as a final polish. Our work was hampered by a fluctuating water table due to seasonal variations and the project management challenge of maintaining cost control and project scheduling. We also had to satisfy the requirements of multiple stakeholders, including the Ministry of the Environment, the Technical Standards and Safety Authority, the local health office, and affected offsite property owners in this rural setting.

As with all our projects, success was accomplished by providing an excellent technical product and accurate project accounting. We prepared detailed scopes of work and cost estimates based on our experience with similar conditions and projects. We managed our efforts and any budget conflicts with our detailed tracking of the project’s progress.

The ground water plume was contained without active remediation and the stable but decreasing nature of the residual impact was documented by post-remedial monitoring. After two years, there was no detectable LPH and plume stability had been achieved. Our transparent and well-coordinated work schedule ensured completion of the project without incident in just over three years.

Our remediation team was chosen for its extensive experience with in situ remediation of contaminated land for school boards, insurers, and government departments. Marc MacDonald has managed more than 500 Phase I and II ESAs involving hydrocarbons, metals, polycyclic aromatic hydrocarbons, PCBs, and solvents. Bruce Cochrane consulted for almost 30 years in the assessment, remediation, management, and abatement of contaminated lands. Together they were responsible for the technical direction, budget maintenance, project management, and communication with clients, regulatory officials, and other concerned parties. Their focus was minimizing the impact and maximizing the efficiency of the cleanup.

Experts on this Case Study

Bruce D. Cochrane

Bruce D. Cochrane

BSc, PGeo

Principal Consultant
Marc MacDonald

Marc MacDonald


Principal Consultant