Environmental impact

When groundsource systems are considered for a project, the environmental consequences of using such a system should form part of the site investigation and the feasibility study of such a system.

There may be site conditions, such as soil or groundwater contamination, that may constitute a direct risk to the drillrig operators or other personnel working on the project, as well as having a cost implication for taking the material of site.

The environmental aspects of the drilling process in itself need to considered especially when a large to very large number of boreholes are being installed. Quality of equipment, materials and workmanship play a key role. Also depending on the ecountered strata, boreholes may need to be sectionally sealed with special clay plugs to hydraulically separate different water-bearing formations and to seal the top of the boreholes as well.

Whilst bringing energy savings & emission reductions as a benefit, BHE systems may have an impact on ground and groundwater, especially when considering redeveloped sites.

Although groundsource can be applied safely to remediated sites, care needs to be taken to avoid the introduction of contaminant pathways and potential health & safety hazards. As a standard the environmental risks should be identified at the feasibility stage, but certainly before work is carried out.

Former Beckton gasworks

The East-London Thames gateway region harbours several former gasworks. After years of neglect, the sites are being remediated and redeveloped for commercial use.

Too meet energy savings goals set, the commercial development at Gallions Reach uses reversible groundsource heatpumps for winter heating and summer cooling.

To avoid contamination of the underlying Chalk aquifer, the 120 boreholes were grouted in the overlying London clay formation, isolating the contamined groundwater

in the upper gravel beds and impeding any unwanted infiltration.