About the affected commercial borehole:

406mm diameter to 78m
Cased to 35m with steel casing
Stainless steel screen to base of borehole with 1mm slots
Geology- Folkestone and Hythe beds (Lower Greensand)

The problems with the commercial borehole included:

• The borehole was pumping suspended solids which had reduced its performance.
• CCTV of the borehole indicated that the screens were partially blocked with encrustation from iron bacteria and manganese deposits.
• Turbulent inflow of water towards the base of the borehole.
• Chemical analysis of the water showed there were high iron and manganese levels.

How we solved reduced borehole performance 

• Mobilised workover rig to site
• Removed existing pumps and riser.
• Cleaned pump in “acid bath ” to remove any blockages on intakes etc.
• Scrubbed borehole walls and screen section using purpose built scrubbing tool.
• Backfilled a section of the borehole base using clean inert silica gravel and install fabricated concrete “plug” 1.5 long to hold gravel backfill in place.
• Developed borehole by using airlift eductor methodology to minimise potential ingress of air to the system.
• Flushed borehole with clearbore product to remove any remaining iron/manganese build up.
• Carried out CCTV survey to assess improvements and install pump on new Certalok uPVC rigid rising main.

As a result of the work we carried out at the paper mill in Kent, the client's borehole screens are much cleaner.

Water now runs clear after the borehole pumps are turned on, and the borehole is now back in full supply.

The client has also benefitted from reduced running and maintenance costs due to having a more efficient borehole and cleaner water.

If you're a commercial or domestic client suffering from a reduced water broehole supply, contact us - we will diagnose and solve all your problems.