Crowhurst Landfill Site, Lingfield

Tank Compliance

Client: Surrey County Council
Project: Tank Repairs, Servicing and Maintenance
Region: Crowhurst Landfill Site, Lingfield
Brief Description

The former landfill site at Crowhurst contained two 50,000 litre above ground storage tanks used for the storage of Leachate water discharged off the landfill site, the tank water levels are monitored and once full, emptied via vacuum tanker.

The water within the tanks containing varying levels of ammonia, methane and other chemicals which reacts with the steel vessel, causing excessive corrosion. This resulted in both tanks failing and the water being contained within the secondary containment of their bunds.

KpH were contracted to carry out a full survey on the tanks condition, which included ultra sonic thickness testing and the issue of a detailed report containing recommendations offering a solution.

The results being one tank was heavily corroded and beyond any kind of viable repair, this was decommissioned and removed from site. The second tank contained two holes, required over plating and welding to repair the leaks. Plates were also welded to other areas which were identified as being weak.

Scope of Works
  • Removal of water from 2 No. 50,000 litre single skinned water storage tanks, including bund contents via vacuum tanker.
  • Confined spaces trained team man entered and cleaned the tanks, removing rust, debris/sludge and associated washings via vacuum tanker to a suitably licensed waste disposal facility.
  • Ultra-sonic thickness testing was carried out to both storage tanks, including visual compliance inspection of tank surfaces, wealds and pipework.
  • Issue test report and recommendations.
  • Hot cut 1 No. tank and bund into suitable size sections and remove from site, disposing of to a licensed re-cycling facility.
  • Confined spaces trained team man entered the second tank, fabricate steel plates and over welded the areas contain holes and heavy corrosion.
  • Wire brush internal surface of the tank and apply 2-part water proof epoxy resin sealer, coating entire internal surface of the tank.
  • Supply generator for task lighting and fume extraction to vent tank, removing epoxy resin fumes.
  • Re-fabricate stairway access and inspection gantry over remaining tank.

The welding of steel plates was carried out as required and the tank lined with a two part epoxy resin to give an extended life to the tank. With the remedial works under taken it is anticipated the tank will give a further 10 years service. The client deemed the capacity of one 50,000 litre tank to be sufficient for the sites future needs, as the amount of Leachate off the landfill having reduced over the years.