Igne’s borehole drilling experts recently responded to an emergency callout from a house builder, whose construction site in Yorkshire was flooding.

The construction client had employed a drilling contractor to install ground source heat pump boreholes.  However, during the installation phase, they had encountered artesian water.

Artesian water is trapped within a confined natural underground reservoir under positive pressure.

Once penetrated, the artesian aquifer’s natural pressure released water from the borehole at roughly 1.2 bar of pressure.

Unfortunately, the contracted company couldn’t deal with the free flowing artesian well and left site.

The client found himself in a situation with the borehole overflowing 24/7, flooding the site and creating difficult conditions for staff and subcontractors to work in.

Fortunately, the client called Igne’s borehole engineering experts who deployed to site immediately to cap the artesian pressure.

How to cap artesian pressure

Igne’s Chris Cox and Ray McGhin attended site to assess the situation and employed the following strategy, capping the artesian pressure and resolving the situation: -

• Using a cement bentonite grout, they pressure grouted the borehole. This resulted in a capping of the artesian pressure.
• They then sealed the borehole to prevent the water coming to the surface again.
• Finally, they cut the steel casing below the ground level and reinstated the ground, leaving it as per the client’s requirements with a gravel surface finish.

Utilising overflowing ground water

On this occasion the client wanted the borehole sealed and the site reinstated.  However, had they chosen to utilise the overflowing ground water, Igne could have pressure grouted the casing and installed a bolted flange before putting on a pressurised cap to make the borehole fully functional.

Managing and indeed utilising an artesian aquifer requires specialised expertise. 

Once a well or borehole is sunk into an artesian aquifer, pressure is released and water comes to the surface - this can result in flow rates from a gentle overflow to a high pressure jet of water.

It’s critical to seal such a borehole or well correctly to protect the integrity of the aquifer.

Capping artesian pressure is an even more specialist procedure.  If not done correctly you can’t seal it and the water will simply continue flowing.

Fortunately, Igne’s borehole team has extensive experience with artesian water.  So, whether you’re currently struggling with an out of control free flowing artesian well as was the situation on site in Yorkshire, or you want to safely and effectively tap into the benefits of an artesian aquifer, get in touch for a free initial consultation.