Oil company now seeking permit to flare up to 10 tonnes of gas per day at Horse Hill

UPDATE: The Environment Agency extended the site’s permit to allow flaring of up to 10 tonnes of gas a day during production. Read more


– despite telling planning decision-makers the gas would be used to generate electricity

Horse Hill Developments Ltd (HHDL) has sought permission to flare up to ten tonnes of gas per day at its controversial Horse Hill oil site in Surrey. 

Theoretically this means up to 3,650 tonnes of gas each year – or enough to heat up to 3,500 homes – could be simply burned, with the energy potentially wasted. [1]

This is a major U-turn on HHDL’s original promise to use the gas from its oil wells to generate electricity.  

The change has been brought to light by the Environment Agency’s draft decision to issue a permit variation for expansion at the Horse Hill site, which gained planning permission in September 2019. The Environment Agency is currently minded to allow this level of flaring; the public consultation closes on 31 March. 

Significant changes from planning permission

The details set out in the application to the EA show some significant changes compared to the planning application approved by Surrey County Council in 2019. The Council granted planning permission to HHDL on the basis that any gas would be used to generate electricity to power the site, with excess electricity being fed into the national grid. Flaring would only occur in the event of an emergency or during maintenance. [2]

Matt Cartwright, Commercial Director of UK Oil & Gas (UKOG, which controls HHDL), personally assured Surrey County Council’s planning committee: “The gas that comes with oil production will be converted to electricity. We are not flaring gas. We are going to tie into the national grid.” [3] 

UKOG had previously circulated a leaflet to residents, saying: “During production, gas will not be flared. The solution gas separated from the oil will be used to generate electricity to power the site and go into the national grid.” The leaflet is on their website here: ‘FACTS ABOUT HORSE HILL: What we ARE doing & what we ARE NOT doing’ 

Yet now HHDL propose to “incinerate natural gas at a rate not exceeding 10 tonnes per day during production operations.” No electricity will be generated under current plans. [4] 

Gas flaring is the burning of natural gas associated with oil extraction. The World Bank says: “Flaring is a monumental waste of a valuable natural resource that should either be used for productive purposes, such as generating power, or conserved.”  The UK has committed to the World Bank’s ‘Zero Routine Flaring by 2030’ initiative and is working with regulators towards eliminating this practice as soon as possible. As well as the impacts on the global climate, flaring poses a risk to the local environment and to human health. [5]

Jamie Peters, Director of Campaign Impact at Friends of the Earth, said: ​​”It is difficult to believe that the Environment Agency would be minded to approve up to 10 tonnes a day of gas flaring at Horse Hill at the time of an energy crisis and climate emergency. The UK needs to urgently ramp up renewables and insulation plans, projects like this should simply not be taking place, especially with such loose regulations as this. “

Sarah Finch, who has been challenging the planning permission in the courts, added “This clearly contradicts the promises HHDL made in order to gain planning permission. Surrey County Council should require a fresh planning application so that HHDL’s real plans can be properly scrutinised.”

Methane leaks

An additional concern is that the application does not address the problems of methane emissions that escape from a number of processes on an oil site. Methane, which is the main component of natural gas, has over eighty times the warming effect of carbon dioxide over twenty years. It  is known to leak from oil sites and other fossil fuel infrastructure and in 2021, campaign group the Clean Air Task Force found methane and other toxic gases leaking from five points at Horse Hill. This problem is so serious that the government has made commitments to reduce methane leaks and to reach a Zero Routine Flaring target by 2030

Lorraine Inglis of Weald Action Group said: “We are dismayed that the EA are minded to approve this controversial permit. HHDL claim they will have methane detection units on-site for this very purpose but they have not shown willing to monitor leaks to date, even after leaks had been exposed by the Clean Air Task Force, so how can we expect them to do so in future? The Clean Air Task Force say inspections for leaks should be monthly. The Environment Agency must regulate these fugitive emissions properly.”


Notes to Editors

[1] Calculation:

  • Up to 10 tonnes of waste gas per day = 3,650 tonnes per year = 3,650,000 kg. 
  • According to page 134 (out of 187) of the Horse Hill Waste Gas Management Plan submitted to the EA, methane density = 0.68 kg/m3. 
  • 3,650,000 kg / 0.68 = 5,367,647 m3 gas = 60,046,646 kWh (using this converter).
  • The average UK home uses 17,000 kWh of gas per year. 60,046,646 kWh gas could therefore provide the annual gas needed for heating and cooking for 3,532 homes. 

[2] The Planning Committee was informed: Four gas-to-power generators are to be installed on the south east corner of the processing area… The generators convert produced gas to electricity which will be used to power the site with excess power being fed into the national grid.” (our emphasis). and

The applicant proposes the installation of an enclosed flare located in the north-west corner of the processing area. They state that flaring will only be used in the event of an emergency or for maintenance.” (our emphasis). [1]

The quotes are from the Planning Development Manager’s report to the Surrey County Council Planning and Regulatory Committee meeting on 11 September 2019. See paragraph 19, page 12 (page 20 of PDF) and paragraph 32, page 14 (page 22 of PDF).

[3] Matt Cartwright’s quote is at 29.15 minutes on the webcast of the Planning meeting 

[4] HHDL’s Waste Gas Management Plan, submitted to the Environment Agency, which covers waste gas from the HH-1 production well and extended well testing of new wells, says: “It is not feasible at this stage to design or order appropriate generators due to having unknown/unreliable gas composition or PVT… In the event additional wells are added to the production line, then a revised Waste Gas Management Plan may consider this option further.”

[5] Letter from the Department for Business, Energy & Industrial Strategy to Ann Stewart of the Weald Action Group, February 2021


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