“Significant environmental effects” likely from UKOG’s National Park drilling plans

Markwells Wood

Map: UK Onshore Geophysical Library

A proposal to produce oil for 20 years from a site in the South Downs National Park is likely to have significant effects on the environment, planners have concluded.

The National Park Authority decided yesterday (12/7/2016) that plans by UK Oil and Gas Investments Limited (UKOG) for production at Markwells Wood could generate extra traffic, produce significant volumes of waste and release pollutants to air, land and water. The rig and lighting could also have impacts, it said.

As a result, the authority has concluded that an Environment Impact Assessment (EIA) would be required before it could consider a planning application.

UKOG’s planning consultant, Barton Willmore, argued in correspondence with the authority in June this year that:

“Significant effects on the environment are not considered likely either alone or in combination with other developments.

“The effects from the proposals can be managed in accordance with standard methods and therefore, the proposed development is not considered to constitute EIA development as defined by the EIA regulations.”

But in a screening opinion published yesterday, the South Downs National Park Authority’s (SDNPA) Director of Planning, Tim Slaney, said:

“The SDNPA has adopted the screening opinion that the development would likely to have significant effects on the environment within the meaning of the 2011 Regulations and does require an Environmental Impact Assessment (EIA).”

Local scrutiny

The decision comes as local people have a chance to comment on UKOG’s plans for the site.

The company is hosting a meeting tomorrow (14 July 2016) at Forestside Village Hall where its representatives are expected to explain proposals to drill up to four horizontal production wells and a vertical water injection well. (Meeting details at the bottom of this post)

In an invitation to the meeting, UKOG told local people it would “shortly be seeking planning permission from the South Downs National Park Authority for a petroleum development project at the existing Markwells Wood oil discovery well site”.

It said the scheme would be in two phases:

  • Phase 1 would include one horizontal production well drilled as a horizontal sidetrack from the existing borehole
  • Phase 2, conditional on phase 1, would have three more horizontal production wells and one vertical water injection well, all drilled from the existing well site.

UKOG said:

“Production is planned to continue over a 20-year period. Once production has ceased all of the wells will be plugged and the site will be restored. “

The company said Markwells Wood was a conventional oil site and there were no plans for hydraulic fracturing.

The site

Markwells Wood is in West Sussex, near Rowlands Castle, on the county boundary with Hampshire. It is in PEDL (Petroleum Exploration and Development Licence) 126. The nearest village is Forestside.

Markwell’s Wood first received planning permission in 2009 (see timeline at the bottom of this DrillOrDrop post).

The wellsite was constructed and drilled in 2010/11. The temporary permission has been extended twice and the current consent, granted in October 2015 under delegated powers, was due to expire on 30 September 2016, when the site should be restored to woodland.

UKOG acquired 100% ownership of Markwells Wood in 2015. The site is operated by a UKOG subsidiary UKOG (GB) Limited.

UKOG said the oil discovered at Markwells Wood was a Jurassic Great Oolite limestone reservoir, the same as that at the Horndean oil field, 3km to the west (source).

Details on environmental impacts

Pollution and nuisances

According to the SDNPA screening opinion, the proposal would have the potential to release pollutants to the air, land and water.

“There is a risk that the development would lead to the pollution of land and water, although this risk should be reduced if the necessary permits can be obtained.

“Vehicle movements associated with the development would generate greenhouse gases.

“Gas may also be generated when oil is extracted. This would be burned in an enclosed burner to reduce the release of substances.

“Some dust associated with the vehicle movements may also be produced. It is likely that artificial lighting would be required during the operational phase which could produce light pollution.

“The drilling of the wells would give rise to vibration, although unlikely to be at significant levels.”


People living close to the site, as well as farmland and ancient woodland, may be affected by lighting, vehicles, noise and any accidents, the screening opinion concluded.

Visual impact

The opinion said that the South Downs National Park and a Grade 2 listed building 600m away may be “significantly affected” by the proposed 37m rig and artificial lighting.

The impact of lighting may “extend over a significant area and may have a particular impact on the residents of Forestside”, it added.

Sensitive areas

The screening opinion said the site was next to an area of ancient woodland and in an Outer Catchment Zone 2 of a groundwater Source Protection Zone. It said:

“Such areas have a relatively low absorption capacity and must be protected.”

Cumulative impacts

In the opinion, the SDNPA said there had already been three temporary planning permissions for the site.

“The proposed development would significantly delay the restoration of the site to woodland which is currently required to be restored by 30th September 2016.”.

It added that outline planning permission for 700 homes at Horndean had been granted and this would result in cumulative impacts, particularly from traffic.

Natural resources

On resources, the opinion concluded:

“Whilst the proposed development would make use of the existing access road and hardstanding, some engineering works would be required to create the proposed wells and erect the necessary rig and associated structures. Such works would require significant amounts of energy.

“Potentially significant amounts of water may also be brought to the site via road with the use of water tankers. The volume required has not been stated.”


The opinion said:

“The development would produce a significant volume of waste during the construction, operation, and decommissioning phases. Waste comprising of rock, mud and water would be produced while the wells are drilled and would be transported from the site via road.”


UKOG’s agent believed the risk of accident would be controlled and adequately managed but the SDNPA opinion said:

“There is a risk of accidents during construction, operational and decommissioning phases.

“An accident could have significant effects on people and the environment due to the nature of the development which would involve the use, storage and production of substances, including oil, gas, naturally occurring radioactive material and Hydrochloric acid which could be harmful to people and the environment.”

Scale of the impact

The SDNPA said:

“It is likely that the effects on the environment will be most significant during phase 2 of the development (involving the drilling of a vertical water injection well and 3 new wells). It is anticipated that each well would take 4-6 weeks to drill.

“There may also be effects on the environment when the side track is created (phase 1) and a continuous impact during the life of the development. It is likely that only the impacts resulting from a significant accident would be irreversible.”

But the opinion added that there could be “permanent effects on the environment connected with the plugging of the wells which would be undertaken once production had ceased”. Effects on groundwater should also be considered, it said.

Meeting details

The UKOG meeting is tomorrow (Thursday 14 July 2016) from 12 noon to 7.30pm, at Forestside and Stansed Village Hall, Broad Walk, Forestside, West Sussex


SDNPA Environmental Impact Screening Opinion

Request by UKOG consultant Barton Willmore for a screening opinion (2)

Updated 14/7/2016 with downloadable PDFs of documents in Links section

This report is part of DrillOrDrop’s Rig Watch project. Rig Watch receives funding from the Joseph Rowntree Reform Trust. More details here

3 replies »

  1. We are very concerned about the impact on our environment both on an individual level as well as a greater scale level.
    When Northern Petroleum did their drilling, we had noise and light problems and the traffic with tankers and lorries was overloading the small roads in spite of their reassurances and they sold the company before it was in production. The wildlife has suffered too. UKOG seems pleasant enough and giving information to the local community, but having just been to an information afternoon I have not come away reassured, as I have been told that for 2 years our environment will be affected by drilling and all that goes with it if planning and production will be successful. This is not a good prospect, two years is a long time to live with an inconvenience like this and I feel powerless to stop this. Also if during this time we or any of our neighbours would like to sell our houses, this would have a financial impact.
    What the effect on the environment will be is not clear from the meeting I went to, except that they say they look into an environmental assessment. We think this should NOT happen in the Southdown National Park!

  2. Unfortunately the potential loss in value of property is not taken into consideration when assessing a planning application. Mike Warrington

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