Spill Impact Assessment
However large or small, spills and leaks can have a significant environmental impact; whether as a result of a single incident or from a series of undetected incidents. Residual contamination can present risks to both environmental and human receptors.
The Darcy team of geo-environmental specialists and chemists are ideally placed to provide an assessment of the broader environmental impacts of an incident and, if necessary, to design and implement a remediation strategy.
To assess and evaluate the environmental impact of residual contamination will typically involve a staged approach.
Phase 1 - Site Inspection and Preliminary Risk Assessment
This involves the collection of all available information on the spill release and the site status. This will include information on the spill material and its properties, volume spilt and timescale. Information on the site geology and hydrogeology will be collated from British Geological Survey solid and drift maps, borehole records, hydro-geological and groundwater vulnerability maps and any previous site specific investigations.
A detailed inspection is undertaken of the site and its surroundings and particular note made of drainage and other features which could provide migration pathways. The location of sensitive environmental receptors such as watercourses is noted and any other aspects which could impact on the scope and location of future investigations.
The collated information is reviewed and the findings used in the development of a ‘Conceptual Model’ for the site of the spill and the initial risk assessment. The information and Conceptual Model are used to identify the pathways by which residual contamination could impact on a receptor and will also be taken into account when designing any requirements for intrusive investigations.
Phase 2 - Intrusive Investigation, Sampling and Analysis
The precise scope of work for an intrusive investigation will depend upon the findings and conclusions of the Phase 1 study. However, if required, the intrusive investigation could involve the construction of boreholes for sampling and monitoring, excavation of trial holes, geological assessment and the collection of soil, groundwater and surface water samples. Ground gas and vapours are monitored if considered necessary. Laboratory analysis of samples is undertaken at an accredited laboratory for chemical parameters related to the contaminant material type.
All findings of the intrusive investigation are reported and evaluated to determine the degree and extent of contamination and the likelihood and severity of residual risks to the environmental receptors identified in the Conceptual Model. The results are used to refine the Conceptual Model and provide a site specific risk assessment based on the source – pathway – receptor model for the spillage site. If unacceptable risks are identified outline recommendations for a course of action or remediation are provided.
For further information on our Spill Impact Assessment service please contact us on 0800 0370 899.
Please note this service is currently available throughout the UK only