UKOG submits new information on South Downs oil drilling – consultation now open


People can now comment on new details of plans to produce oil for 20 years at Markwells Wood in the South Downs National Park.

The company behind the project, UK Oil and Gas Investments PLC, submitted 22 additional documents this week to support its planning application. This was in response to a request by The South Downs National Park Authority, which will decide the application, for more information on impact of the scheme on groundwater, landscape, traffic and wildlife.

A public consultation is now open and runs until Tuesday 28 March. There have been more than 2,000 objectives since the application was submitted in September 2016.

UKOG wants to drill a new horizontal well from the existing borehole at the site, as well as up to three additional production wells and a water disposal well. The application also seeks to produce oil for 20 years at the site near Rowlands Castle on the West Sussex-Hampshire border.

DrillOrDrop reviewed the original planning application (link here). We’ve looked at the new documents and identified some of the key changes and new information.

Impact on groundwater

The Environment Agency and Portsmouth Water said the risk assessment of groundwater pollution in the original application was not sufficiently detailed and they objected to the plans.

A key concern was whether fissures in the chalk aquifer could connect the site to the public water supply at Havant and Bedhampton Springs. Chalk also has underground channels, eroded by solution weathering, along which water can travel rapidly, known as karstic flows.

A new risk assessment said the chalk near the site had “less potential for solution weathering and karstic flows” than other areas in the South Downs. It said:

“Consequently, there is not the same potential for rapid groundwater movement from the site to the public water supply at Havant and Bedhampton Springs, as there is elsewhere in the catchment.”

It said the highest risk of contamination – assessed as medium – was during well construction. The assessment concluded:

“The risks associated with the proposed development and transport route can be mitigated and residual risks are ‘very low’. The only exception is the ‘low’ risk that is associated with drilling new wells through the Chalk aquifer to set casings. This risk cannot be eliminated but can be mitigated and is no greater than the risks associated with conventional water well drilling.”

The risk assessment said risks would be reduced by

  • Containing surface water runoff at the site and removing by tanker
  • Plant, equipment, tanks and materials required for operations would be in bunded areas and any water runoff contained and removed from the site
  • New wells would be cased to below the base of the Lower Chalk
  • Drilling would use biodegradable drilling fluid
  • Reverse circulation techniques would reduce potential losses
  • A traffic management plan would minimise the likelihood of collision on the access track and route used by heavy goods vehicles.


The maximum number of two-way heavy goods vehicle (HGV) movements is put at 20 per day during drilling rig mobilisation and demobilisation. This covers a total of 16 days. The average number of HGVs would be 10 two-way movements per day, documents stated.

Construction traffic would increase HGV movements on local roads by 4-23%.  Traffic during operation phases would increase HGVs on local roads by 2-11%.

UKOG traffic movement update Markwells Wood

Production volumes

The new documents indicated that average daily production would be 230 barrels. The company said it could be up to 700 barrels with a maximum of five tanker movements in and out of the site.

But consultants for the company said:

“Further to discussion with UKOG they have confirmed that 1 tanker per day [230 barrels] (during the permitted days) is the average across a 20-year period.”

Air quality

The updated development programme puts the maximum number of two-way HGV movements at 20 per day, with a 12-month average of 10 per day. An air quality update said an increase of fewer than 100 HGV movements a day was unlikely to lead to significant air quality impacts. It added:

“The associated daily average flows of HGVs travelling to and from the site associated with Phase 2 [drilling] may exceed 15 additional movements a day for a period of around one year. However, pollutant concentrations alongside these roads are well below the air quality objectives and such an increase is not considered significant.”

The documents said gases from the well would burned in a flare. This would operate at about 1,000 degrees C, helping to “minimise the release of gaseous VOCs” [volatile organic carbons], they said.

An ecological report said nitrogen oxides may be deposited on surrounding plants but “implementation of emission control procedures will reduce NOx levels to below the threshold known to adversely impact terrestrial plants.”

CO2 emissions

The documents put peak CO2 emissions from HGV movements at 517 tonnes per year or 6,084 over the “operational period of the development”. The development itself was estimated to emit 65,659 tonnes of CO2.

Peak annual CO2 emissions for the who project was estimated at 3,704 tonnes a year or 71,744 tonnes for the period of the development. The total emitted for West Sussex in 2014 was 4,236,200, the documents stated.



A new ecological report identified wildlife species and habitats around the site and assessed the impact of the proposed well.


Seven species of bats were recorded near the site and nine in the wider area. The species include rare Leisler’s and Bechstein’s bats.

The well pad would be illuminated and this was likely to deter bats but it has “negligible value to bats”, the report said. Surrounding habitats, which would provide foraging and community habitats, would remain dark, it said.

Bechstein’s and brown long-eared bats may perceive some drilling noise but this was unlikely to deter them from foraging, the report said. Residual impacts were assessed as “non-significant adverse”


Four active badger setts were identified within 100m of the site and two within 20m.

Badgers are legally-protected and measures may be required to prevent disturbance during enabling work, the report said.

Badgers would not be affected by lighting but during drilling there would be a small reduction in foraging habitat and the disturbance of three setts for up to six months. Residual impacts were assessed as temporary significant adverse


What was described as a “moderate population” was identified next to the access track. Legally-protected and measures would be needed to prevent them being killed or injured during site and enabling work, the report said. Slowworms may be deterred by noise and vibration but there were other suitable habitats, the report added. Residual impacts were assessed as negligible

Breeding birds

Red list species (birds increasingly at risk) were identified in woodland and farmland next to the site. These included yellowhammer, skylark and starling. Birds are legally-protected from disturbance during breeding. The report said measures would be needed to prevent disturbance during site and enabling work if this took place in the breeding season. The report added:

“Vehicle movements on the access track, and noise and vibration from the well pad and nocturnal lighting may deter birds.

“It is likely that most birds will initially move away from the Site and return to the area as they become habituated to the disturbance; however, if the Phase 2 operations [drilling] begin during the bird breeding season, then it is possible that some birds may abandon their nests. Most passerine birds will have a second brood if the first nest fails and so this is unlikely to have a negative impact on their populations; however, many raptors, such as hobby and red kite, which are known to occur in the area, generally have one brood per year and so nest abandonment could result in no fledglings for one season.”

Residual impacts were assessed as negligible


The application proposes to create 1.55ha of mixed deciduous woodland at the end of production. This would have a minor benefit to bats, badgers, reptiles and breeding birds, the report said.

Future surveys

The report recommended a badger survey before each new phases of drilling to record any new badger setts. If site work stopped for more than two weeks during the nesting season, the surrounding habitats should be rechecked for birds that re-colonised the area.


The new documents confirmed that no trees would be lost to implement the development.


The new assessment said

“No level of sky glow is [currently] visible above the Site. It is likely that the Development will result in levels of sky glow above the Site, should suitable measures not be undertaken to limit the impact. The overall impact of the Development’s lighting design and installation will be based on the best practice design guides. The Development will then have minimal sky glow, excluding the warning beacon on the drilling derrick, and therefore not impacting the residents surrounding the Site.”

Landscape and tranquillity

The new material acknowledged that the value and sensory quality of the surrounding landscape was very high. CPRE puts the area as among the most tranquil parts of West Sussex.

A landscape update identified a conflict between the wooded areas and the rig and the flare stack.

“The perception of the site will be changed by the introduction of vertical man-made structures, associated cabins and squat tanks; as well as by site traffic, HGV traffic and associated movement, noise and light at source. These additional man-made structures will conflict with the naturalistic landscape as experienced within the locality.”

It added:

“During site enablement, the magnitude of change is predicted to be medium at a local scale which, when combined with a high overall sensitivity, yields a moderate adverse effect. This is a significant but temporary effect.

“The verges of rural lanes may be impacted on by HGV traffic in situations where these are required to pass oncoming vehicles.”

The new assessment said the tranquillity of the area would be interrupted but this would be limited to a distance of about 1km from the site. The views from some viewpoints would be changed completely but this would be temporary.

The report added: the “site itself is not unspoilt, lies within an intensively managed agricultural environment and that effects are fully reversible. Long-term benefits following restoration will also be evident contributing to a beneficial effect on the South Downs National Park.”

Alternative sites

New details suggest UKOG looked at 12 potential sites but discounted nine for environmental reasons including what were described as “adverse effect on views from the public right of way network, loss of agricultural land, topography and access issues”.

The documents said:

“Further analysis of the three remaining sites found that the existing Site was most suitable for the Development. This is mainly due to the fact that the Site contains existing infrastructure, including a well pad and suitable access and would make best use of previously developed land. No alternative uses for the Site have been considered as the previous oil exploration and testing carried out at the Site have shown it is suitable for further development.”

Cumulative effects

The new material said:

“No cumulative effects are anticipated. The Site is geographically and visually separated from the cumulative site at Horndean and its broader study area, such that it would not result in additional effects on landscape character and visual amenity.”

Link to application

The new information is listed under the documents tab and dated 6 March 2017.
Comment on the proposals here (you will need to logon to the site or register if you haven’t done so previously).

2 replies »

  1. This is utterly disgraceful too even consider, the beautiful landscape will be ruined and insight will be a massive drill with fumes coming out of it. There is no way to contain acidisation, your pouring waste into the ground and adding hazardous chemicals which will ruin and contaminate the water. This really isnt rocket science these oftshore non taxpaying corporations want to destroy our beautiful country as they have most other countries. Please research fracking issues and ask yourself would you like to have this on your beautiful landscape and have oil coming into your water to poison you. I dont think anyone has a clue the damage this will cause

  2. It seems to me that ancient woodlands should not even be considered for drilling. The possibility of contaminating drinking water, especially, has not been sufficiently considered. This should concern even those who do not care about landscape. I fail to see the point of designating National Parks if drilling for oil is allowed in them every time the profits exceed a certain figure. Besides, though the company has said “up to” 700 barrels could be produced, their own figures show the average is only 230 – well under half that ! If they are equally cavalier with the figures they use for environmental damage, they can’t be trusted. There is a long history of projects whose safety was supposed to be guaranteed and which turned out disastrously (wasn’t the Titanic supposed to be unsinkable ?) I am also unimpressed by the claim that the visual impact will only affect 1 square kilometre. I very much doubt it and in any event, that is 1 square kilometre too much.

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