The oil site at the centre of a landmark Supreme Court judgement on climate emissions continued “unlawful” operations, despite announcing work had been suspended.

The Horse Hill site in Surrey produced oil in November 2024, even though its planning permission had been quashed about five months earlier and the operator had previously announced it was voluntarily suspending oil production.

But official data, submitted by the operator, HHDL, to the industry regulator, showed that there was still oil production and gas flaring at Horse Hill in November 2024.

The data, released earlier this month (February 2025), showed Horse Hill produced nearly 14 barrels of oil per day or a total of 65m3 of oil in November 2024.

The November 2024 volume was under a third of the Horse Hill monthly average from the previous two years. But it was still higher than that for four other oil production sites in England.

Horse Hill also flared (burned in a flare) 2.5ksm3 (thousand standard cubic feet) of associated gas during November 2024. This was gas extracted from the site along with the oil. Like the oil volume, it was under a third of the monthly average.

In the five months since the Supreme Court judgement, for which data is available, Horse Hill produced 641m3 of oil and burned 28ksm3 of gas.

Sarah Finch, the campaigner who successfully brought the Supreme Court case on Horse Hill, said the continued production at the site showed that “relying on oil and gas companies to do the right thing voluntarily will never work”.

There have been repeated calls for enforcement action against the continued operation at Horse Hill after the Supreme Court ruled that planning permission unlawfully failed to take into account carbon emissions from burning Horse Hill oil.

Surrey County Council confirmed in December 2024 that equipment was to be removed from Horse Hill.

Explanation

We asked HHDL’s parent company UK Oil & Gas plc (UKOG) for an explanation of the November 2024 production. The company did not respond.

We also asked Surrey County Council why Horse Hill was apparently continuing to operate, despite the assurance of a voluntary suspension.

A statement to DrillOrDrop today said the council had been told the site “needed to enter a period of ‘minimum maintenance flow” (see full statement at the end of this article).

A council spokesperson said:

“Although the intention to initiate this flow was outlined as part of UKOG’s proposed suspension programme, the council remained clear that the development at the site was unlawful”.

The spokesperson said the council had “sought to engage” with other regulators, the Environment Agency and Health and Safety Executive, to “interrogate the operator’s claims that the ‘minimum maintenance flow’ was necessary for safety reasons whilst they [UKOG/HHDL] removed the development from the site”.

The statement added that the maintenance flow stopped on 15 November 2024.

A site inspection on 28 November 2024 found that pump was “non-operational and the gas flare was observed being removed from the site”, the statement said.

Reaction

Sarah Finch, who won the Horse Hill case at the Supreme Court, told DrillOrDrop today:

“That UKOG continued to produce oil so long after planning permission was quashed shows that relying on oil and gas companies to do the right thing voluntarily will never work.

“Planning authorities and other regulators must use the enforcement powers at their disposal rather than hoping for the best.

“I’m glad to hear that Surrey County Council and the Environment Agency are monitoring the site and working to remove the unlawful development.”

Information request

DrillOrDrop used the Freedom of Information Act to ask for correspondence between Surrey County Council and HHDL/UKOG between the date of the Supreme Court judgement and 30 October 2024.

The council released some correspondence but withheld other documents. We did not receive the company’s suspension programme mentioned in the Surrey County Council statement.

The council explained its reason for withholding some documents:

“Disclosure would prejudice, or would be likely to prejudice the course of justice, the ability of a person to receive a fair trial or the ability of a public authority to conduct an inquiry of a criminal or disciplinary nature.”

We have asked for this decision to be reviewed because of the public interest in what happens at Horse Hill. Under the rules, the council must tell us the result of the review by 3 March 2025.

We have also requested correspondence between the council and companies for the period 1 November 2024 to 7 February 2025.

Full council statement on continued production

“UKOG/HHDL informed the Council that commercial production was preliminarily ceased on the 25th October 2024, they also made a public statement regarding this cessation. The Council confirmed the cessation of this commercial extraction in an inspection on the 31st October 2024.

“Following this initial period of cessation, the Council continued to discuss with the operator how the unlawful development would be removed from the site and asked for their programme to complete this.  As part of these discussions, the operator advised the Council that the site needed to enter a period of ‘minimum maintenance flow’.  Although the intention to initiate this flow was outlined as part of UKOG’s proposed suspension programme, the Council remained clear that the development at the site was unlawful and sought to engage with our regulatory partners (EA/HSE) to interrogate the operator’s claims that the ‘minimum maintenance flow’ was necessary for safety reasons whilst they removed the development from the site.  The Council remained engaged in these discussions with our partners when the maintenance flow ceased on the 15th November 2024, as part of the operator’s programme for suspension of the site. In a site inspection on the 28th November 2024, the pump was observed to be non-operational and the gas flare was observed being removed from the site, confirming that extraction was no longer practically possible.

“The Council remains engaged in monitoring the site and working to remove the unlawful development.  A further site visit was carried out on 4th February with colleagues from the Environment Agency who are also monitoring the site in respect of their regulatory role. At this visit the cessation of extraction/production was further confirmed and officers are satisfied that the site continues to move towards suspension. This will continue to be monitored.”

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