What If Only The Fill Point Is Visible?
An old fill pipe, vent or inspection cover may be the only clue that a tank remains beneath a garden or driveway. Do not assume a disconnected boiler means the tank was removed. Start with property records, previous surveys and any installation or decommissioning documents, then arrange an assessment of what is actually present.
Tell us whether the tank is still supplying equipment, partly buried or believed to be redundant. Avoid opening unknown covers or digging to locate the shell. Tank position, construction, historic contents and nearby services all affect the work, and an apparently simple clearance can need specialist investigation before a method is chosen.
Should The Tank Be Excavated Or Left In Place?
Removing an unused tank provides the opportunity to inspect the surrounding excavation and remove redundant pipework. Environment Agency guidance starts from removing underground tanks and pipes that are unlikely to be used again. Practical constraints can change the approach, particularly where a tank sits beneath a building or close to foundations.
Decommissioning in place can be considered when excavation is impractical, subject to assessment. It still requires fuel and residues to be removed and the tank cleaned and made safe before suitable filling. A filled tank remains in the ground. It must never be described in property documents as though it has been removed.
Does Filling Deal With A Previous Leak?
Filling a vessel does not treat contaminated soil or groundwater around it. An unexplained loss of fuel, oily ground or a persistent smell needs its own investigation. The decommissioning proposal should distinguish making the tank safe from finding and addressing pollution beyond its walls.
Environmental assessment may involve sampling and a separate consultant, with findings shaping the excavation or clean-up plan. Tell the contractor about wells, boreholes, springs and nearby drains or streams, as well as any previous insurance claim. Do not agree to immediate backfilling if suspected contamination has not been assessed and recorded.
How Is The Groundwork Planned?
The investigation establishes access for equipment, the tank’s position and the relationship to buried services and structures. A garden suitable for a person to walk across may not support excavation or lifting equipment. Walls, narrow entrances and changes of level can affect how spoil and the tank leave the property.
HSE’s HSG47 guidance covers planning, locating and identifying buried services, and safe excavation. The contractor needs to apply an appropriate method before digging begins. Ask how service locations will be checked, where materials will be held and what exclusion area is needed, especially if the property remains occupied or shared access must stay open.
What Happens To Fuel And Residues?
A buried tank may contain more liquid than expected, even if it has been unused for years. Remaining fuel needs assessment before any reuse is considered. Oil, water and sludge are managed before the tank is lifted, cut or filled, with precautions for residue and vapour appropriate to the work.
If usable fuel is to go into new above-ground storage, coordinate the receiving installation in advance. Temporary holding, sampling and waste removal can influence the sequence and cost. Never attempt to pump the contents into household containers, enter the vessel or arrange cutting before a specialist has assessed and made it safe.
What Should The Price Include?
Tank depth and size, ground conditions, structural constraints and machinery access determine much of the cost. Breaking out concrete, removing spoil, testing soil and reinstating a driveway are distinct items. A quotation should state what is known, what remains uncertain and how unexpected discoveries will be handled before additional work proceeds.
Agree the intended finish, including whether the excavation will be backfilled or handed to your builder under an agreed arrangement. If the tank stays in place, confirm the proposed filling material and its suitability for future use above it. A future building or vehicle-loading proposal may need separate structural advice.
Which Records Matter Afterwards?
Keep a marked location plan and a description of the work, together with the tank’s known capacity, former contents, date and method of decommissioning. Retain relevant waste, inspection and environmental records. Tell your insurer if a decommissioned tank remains, and provide accurate information to future buyers and contractors.
To begin, send your Somerset postcode, photographs of visible covers and pipes, old plans if available and an explanation of the proposed use of the land. Mention any past oil loss, the route for equipment and nearby water sources. A survey is particularly useful when the position or condition is uncertain rather than relying on photographs alone.
Your Questions Answered
Can You Quote Without Knowing The Tank Size?
An underground tank enquiry can begin without an exact capacity, but a firm scope may require investigation. Share old plans, invoices, photographs of visible fittings and anything known about its history. Do not excavate to measure it yourself, as buried services, unstable ground and residual fuel hazards need assessing before disturbance.
Can A Filled Tank Be Used Again?
A tank permanently filled during decommissioning should be treated as out of service. Filling is not a way to preserve working oil storage for later reuse. If future fuel storage may be needed, discuss a suitable new installation and keep accurate records of what remains below ground for future contractors and property transactions.