It helps determine how likely it is that a site will pose a threat to groundwater (or whether contamination has the potential to spread through an aquifer) and what needs to be done to manage this risk. In the UK, you will usually need one if, for example, you are developing greenfield land; brownfield involving change of use or simply remediating a chemical spill, etc.
Thank you for reading this post, don't forget to subscribe!You are likely to be asked for a groundwater risk assessment if the site sits over a vulnerable aquifer, is in proximity of controlled waters (streams, rivers, lakes) and/ or proximal to private water supplies. It may be projects such as basements, piling or deep excavations that interact with groundwater directly because these structures change flow paths and can mobilise contamination.
What does it include? A good assessment pulls together:
Site specific: geology, hydrogeology, groundwater depth to the water table or potentiometric surface, type of aquifer present on site, nearby receptors and abstractions.
Contaminants of concern, where they might go (pathways); who or what could be exposed.
Using a source-pathway-receptor model
Investigations: Boreholes, monitoring wells, groundwater levels and sampling results over time.
Risk characterisation (comparing to appropriate benchmarks and guidance, including uncertainties)
Recommendations: Continued monitoring, remediation alternatives, construction restrictions (i.e. vapour barriers) and any continuing maintenance required (e.g., long-term monitoring or prohibition of infiltration). For Groundwater Remediation, contact https://soilfix.co.uk/services/groundwater-remediation/
More commonly, the output is an unambiguous report based on evidence that can be relied upon for decision-making by both planners and regulators, as well as project teams, preventing expensive surprises once ground works commence.