Work van and compressor for the foam filling project

Case Study — Domestic Foam Filling

Underground Heating Oil Tank Foam Filling

A redundant buried heating oil tank in a Bicester back garden, emptied and decommissioned by foam filling in a single visit.

Bicester, OxfordshireSeptember 2026Domestic project
Up to 3,000L
Estimated tank capacity
~500L
Heating oil removed
One day
Project completed
Certified
Foam fill certificate
Project Overview

A buried tank
no longer needed.

A homeowner in Bicester, Oxfordshire, had an underground heating oil tank in the back garden that was no longer in use.

The tank sat behind a shed, reached through a narrow garden passage that made access for excavation machinery difficult. Foam filling offered a practical way to decommission it in place: first pump out the remaining heating oil and water, then fill the tank void with inert foam, avoiding excavation of the garden.

Britteco carried out the oil tank decommissioning in a single visit and issued a Foam Fill Certificate for the homeowner’s property records.

The Challenge

Garden access.
Oil still inside.

01

Oil to remove

Around 500 litres of heating oil remained in the tank. We pumped out the old fuel together with the water present before foam filling.

02

A narrow access route

Parking was at the front of the house, approximately 20 metres from the tank. A 20–25 metre hose run connected the equipment to the back garden.

03

Estimated tank capacity

The tank was estimated at up to 3,000 litres. Its exact capacity was unknown.

What We Did

Empty first.
Then foam fill.

01

Remove the heating oil and water

We brought a fuel pump and two IBC containers to site, pumped out the remaining heating oil together with the water present and checked the tank was empty before filling.

02

Fill the tank in place

The foam line ran from the front of the property to the tank in the back garden. We filled the tank void with inert foam without excavating the garden.

03

Record and certify

We recorded the quantity of foam used and issued a Foam Fill Certificate documenting the work.

The Project in Pictures

Working through
limited access.

The tank access, equipment and narrow route through the garden.

Pumping out the remaining heating oil and water before foam filling the tank.
Pumping out the remaining heating oil and water before foam filling the tank.
Foam filling equipment and hoses in the narrow garden access route.
Foam filling equipment and hoses in the narrow garden access route.
The narrow passage leading to the tank behind the shed.
The narrow passage leading to the tank behind the shed.
Foam filling the underground tank, with foam visible at the access opening.
Foam filling the underground tank, with foam visible at the access opening.
Watch the Work

See the foam filling
in action.

A closer look at the foam being introduced through the underground tank access.

After pumping out the remaining heating oil and water, we ran the foam line through the narrow garden passage and filled the redundant tank in place.

The footage shows the foam at the access opening and the equipment used for this Bicester project. The garden did not need to be excavated.

Watch on YouTube

The Result

One visit.
No excavation.

The work was completed in one day. The remaining heating oil and water were pumped out before the redundant tank was foam filled in place.

The garden did not need to be excavated. The homeowner received a foam fill certificate to retain with the property documents.

For this project, underground oil tank foam filling avoided the access and reinstatement work that excavation would have involved.

Common questions

Frequently Asked Questions

What is an alternative to removing a buried oil tank?

Decommissioning it in place. The remaining oil and water are pumped out, the tank is checked empty, and the void is filled with inert foam. The tank stays in the ground, so the garden does not have to be excavated.

Does an old underground oil tank have to be removed?

Not always. When a tank is no longer used, the priority is to empty it and make it safe. Where digging it out would be difficult or disruptive, as it was behind a shed in this Bicester garden, filling it in place is a practical and recognised option.

What happens to the oil and water left in the tank?

We pump them out before any foam goes in. On this job around 500 litres of heating oil and water were transferred into IBC containers and taken away for proper disposal.

Do you need machinery access to the back garden?

No. Parking was about 20 metres from the tank, so we ran a 20–25 metre hose line through the garden passage. That is often enough to reach tanks behind houses, sheds or outbuildings.

Will I get paperwork for my property records?

Yes. We record the quantity of foam used and issue a Foam Fill Certificate. It is useful when you sell the property, as buyers’ surveyors often ask what happened to an old buried tank.

Domestic Tank Services

Old tank under
your garden?

Send us a few photos of the tank access and surrounding area. We can discuss foam filling, heating oil removal and the practical options for your property.

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