When groundwater becomes contaminated, removing it completely is not always practical. In many cases, treatment takes place underground, where the pollution sits. This approach is known as in situ groundwater remediation – it avoids large-scale excavation, so it can reduce disruption at the surface.
Treating contamination below ground
In situ methods work by introducing materials or processes directly into the affected area. Small boreholes are drilled into the ground so treatment agents can be injected into the water-bearing layer. These agents might break down pollutants chemically, or encourage naturally occurring bacteria to digest them.
This type of groundwater remediation is often chosen for sites where contamination has spread beneath buildings or infrastructure. By treating the water in place, there is less need to pump large volumes to the surface. Over time, monitoring wells are used to test whether pollutant levels are falling.
Common in situ techniques
Different techniques suit different contaminants and the selection of an in-situ remediation technology should be site specific.
Oxidation uses chemicals to react with harmful compounds and turn them into safer substances. Bioremediation supports microbes that feed on pollutants. Permeable reactive barriers can also be installed underground to filter water as it flows through.
Details of these approaches can be found at //soilfix.co.uk/services/groundwater-remediation where typical treatment options are outlined in more depth.
In situ groundwater remediation usually takes place over months, not days. Regular sampling checks progress and ensures the method is working as it should be. In situ remediations can provide an effective and less intrusive solution for managing contaminated groundwater beneath the surface.
