Vertical borehole drilling services in Guildford, Surrey. Skip to main content
Borhole drilling with ASL Limited

Borehole drilling enables ASL to drill through unsuitable layers to ground levels that are suitable for land drainage.

Borehole drilling services

Vertical ‘borehole’ drilling

Borehole drilling (vertical drilling) creates a deep, narrow hole in the ground, typically using different sized augers ( a tool resembling a large corkscrew, for boring holes ) to make the hole. This then becomes known as a borehole and can be used for surface water or clean treated water from a treatment plant disposal, in the form of a deep bore soakaway. This would require a permit from the Environment Agency.

Borehole drilling a soakaway is one choice when the land available for development isn’t suitable for conventional soakaway designs.

There is no need to worry about finding a borehole drilling company because ASL offers soakaway borehole drilling services across a large section of the South East – see if we cover your area here. 

ASL Limited offer:

  • Borehole design
  • Borehole installation
  • Free quotes
  • Percolation tests
  • System analysis
  • Experienced engineers

When is borehole drilling used?

Borehole soakaways are used when there is poor ground porosity for the first 5 meters into the ground. Therefore it is not suitable for a conventional trench or pit type soakaway. This could be due to an area with a heavy ground make-up of clay – which is non-porous – or other adverse ground conditions. However, you may find a chalk layer or gravel beneath the clay you can use to receive the excess surface water or even treated discharge from your private sewage system (with an appropriate permit). We can get through that unsuitable ground with the borehole drilling to reach the porous ground underneath.

What we do.

To determine if a borehole soakaway would be beneficial in your area, we would first examine the geological data for that region and confirm if there is a chalk layer. For example, a few of the larger regions that we serve in Surrey would be confirmed as having a chalk layer in the earth. If we examine your property's area, and there is a chalk layer, we will then move on to determining at which depth it is positioned.

Once we have established the chalk layer's depth, we can use our auger to drill through the ground to a depth of up to 13m with a diameter between 150mm – 600mm. Once the hole has been created, we will install a plastic pipe perforated at the chalk layer's depth to allow the excess surface or treated water to disperse evenly. The pipe would then be surrounded by flintstone and finished using a concrete cap to allow future access to the borehole if required.

We will provide you with the best system suitable for all your needs.

  • Our services include the design, installation, maintenance and repairs of your private water disposal system. 
  • We can cater for any size buildings, from one-bedroom properties to large commercial and industrial sites. 
  • Our borehole specialists are on hand for any impartial advice and support for your system.


Moling and directional ‘horizontal’ drilling.

For horizontal drilling services from ASL Limited please go to our moling and directional drilling page.


Don’t delay we can help you today!

Call 0800 181 684 for all your drainage needs.

Our HQ is based in Guildford, but we cover locations within the home counties and the South East of London.

See the map below for the Areas we cover.

Available 24 hours a day, 7 days a week across the South East

A Surface Water Warning

It must be noted that if surface water enters your system in a surge, such as during heavy rainfall or a storm, it is possible that it will stir up wastewater already present in the system. This will ruin any separation that has already taken place and allow larger buildups of effluent to pass through the system without being treated. If you suspect that too much surface water is being allowed into your sewage treatment plant, you may wish to have a CCTV drain survey conducted through us.

We can use the most up-to-date, flexible cameras to take detailed footage of your drains, locating the source of the issue and helping you to get it fixed afterwards. We may also suggest that roof water down pipes and surface water gullies are checked, to ensure that they are not flowing into the foul water drain on your property.

ASL Limited Certifications

Our engineers have a variety of certifications, as follows:-

  • New Roads & Street Works
  • EUSR Water Hygiene
  • CSCS
  • NPORS Excavator & Dumper
  • Confined Space

We are also Safecontractor approved, as well as being part of Which Trusted Traders and Check-A-Trade.