The main objective of a site risk assessment (SRA) is to fully evaluate the potential risks to humans and ecological health due to the presence of contaminants at the site and to determine the appropriate management measures to mitigate unacceptable risks. These management measurements may include contaminant recovery and plume containment. MEK will review all available environmental investigation reports together with technical guidance literature on the site and prepare a detailed SRA report for your site.
Site Risk Assessment
Delineation of Contaminated Areas
Based on the outcomes of Phase II and III ESAs, the horizontal and vertical distributions of contaminants in the soil and groundwater systems are determined. This is accurately done using our groundwater flow and contaminant modelling software. Using the conceptual site model, we are able to generate “slices” to obtain cross-sectional views of the subsurface and determine the variation in contaminant plume concentrations with depth to develop an effective site remediation plan.
Remediation Action Plans and Implementation
MEK staff have prepared several remedial action plans (RAPs) over the years. These plans are developed based on the findings of the Phase II and Phase III ESA assessments conducted at the sites. Our final RAP reports usually consist of four parts: background, the scope of remediation, post-remediation, and a concordance table listing the contaminants of concern, potential impacts, and any regulatory requirements.
The background section of the RAP will provide a concise summary of the data, conclusions, and recommendations obtained from the ESA assessments completed at the site and will include surface, subsurface, and contaminant characterization information.
Our RAPs will usually address the following concerns:
- Identification of the major contaminants of concern and the basis for their selection;
- The main objectives of the remediation and the justification for the intended objectives;
- A detailed description of the method and techniques for implementing the remediation;
- The type and quantity of sampling and analyses to be done and the quality control and assurance measures that must be put in place;
- Emergency plans to mitigate potential adverse effects to adjacent receptors, such as humans, water wells, surface water, livestock, vegetation, and wildlife; and finally
- A schedule for carrying out the RAP.
Typically, the post-remediation component will address:
- The long-term monitoring program, including details and timing of the sampling and the analyses required;
- Erosion control measures that may be required during and after remediation of the site;
- Slope stability challenges resulting from site disturbance;
- A contingency plan to address new contaminants that may be identified during the course of the remediation; and
- The extent of reclamation and restoration required to return the site to a productive or natural state.