When Groundwater Remediation Is Needed
Industrial or Commercial Land History
These are typically old industrial sites, left over from fuel storage (petrol stations), dry cleaning, engineering works and chemical storage sites. Over time the fuels, solvents and heavy metals have leached down through the soil into the groundwater. They can travel long distances underground, often passing hundreds of meters from where they were originally released, and can still cause problems many years after they have been placed on the surface.
Phase 2 Site Investigations
Phase 2 environmental site assessment (ESA) will confirm historical risk identified during Phase 1 environmental desk study. However, where Phase 2 sampling identifies contaminants in the groundwater at concentrations above relevant screening values, then groundwater remediation is required and is no longer discretionary.
Planning and Change-of-Use Requirements
Planning and Change-of-Use Requirements. Remediation requirements can be included as planning conditions for any residential development or permitted development (such as a change-of-use from retail to residential) proposed for a brownfield site. Such conditions would need to be discharged before construction commences and would be a matter for the local authority and Environment Agency.
Proximity to Source Protection Zones
Groundwater source protection zones can be checked to see whether they relate to your site and what their classification is (SPZ1, SPZ2 etc).
Natural Attenuation Has Stalled
Whilst monitored natural attenuation is the agreed strategy for a site, regular sampling results must indicate that the contaminant levels are either plateauing or increasing, thereby indicating the need for active treatment. A useful reference for Groundwater Remediation is https://soilfix.co.uk/services/groundwater-remediation/.
Where your site has any of these characteristics then a site investigation needs to be started as soon as possible to ensure the simplest and most cost effective solutions are implemented.
