Frequently asked questions

During ONE-Dyas’ discussions with stakeholders, a large number of questions were asked and answered. We have listed them here. Is your question not included? Please feel free to send us an e-mail. You will get an answer as soon as possible.

Construction and installation operations

After obtaining the N05-A development permit from the Dutch government on 1 June 2022, ONE-Dyas, together with partners EBN and Hansa Hydrocarbons, made the final investment decision in September 2022. A decision involving an amount of over EUR 500 million.

Shortly afterwards, concrete preparations began, such as contracting companies for the construction of the pipeline to the NGT pipeline and of the cable for the electrification of the platform, for the drilling of the well and, of course, for the construction and installation of the platform.

In December 2022, construction work on the platform started at the Schiedam yard, with the aim of completing the platform for installation in the North Sea by summer 2024.

The preliminary injunction court suspended part of the N05-A permits in April 2023 due to the general nitrogen problem in the Netherlands, which for various reasons challenges almost all large-scale construction projects in the Netherlands. The suspension applies only to temporary construction work in the North Sea.

The procurement and construction of the N05-A facilities (such as the platform) are not hindered by the court ruling and has continued as planned. Following a positive ruling in the court case on the merits, filed by opponents of this North Sea project, construction works on the North Sea will start to ensure natural gas availability by the end of 2024. The court ruling is expected from mid-April 2024.

Recent questions from the island of Borkum (March 2023)

Moving towards a completely CO2-neutral energy supply, natural gas is still an indispensable part of energy supply, for cooking and heating our homes. A recent study [by TNO and CE Delft, commissioned by the ‘Noordzeeoverleg’] confirmed that local gas production in the Netherlands will be lower than gas consumption until at least 2047.
In the energy transition, we need a multitude of solutions, of which natural gas from this project is one. It has been agreed with the Dutch and German governments that gas production is for domestic use only, and furthermore stops when there is no more demand.

We have agreed with both the Dutch and German governments that production is only for domestic demand. If there is no more demand, gas production will also stop.

All studies show that the risk of earthquakes is negligible. The licensing procedure for gas extraction is according to the strictest safety and environmental requirements. If there were a real chance of earthquakes, the Dutch Ministry of Economic Affairs and Climate would not grant the licence. According to the Dutch Civil Code, mining companies are liable for damages and therefore all gas operators in the North Sea have insurance for possible damages.

Monitoring will take place through satellite data. Special equipment will be installed on the platform and at the Riffgat wind farm for this purpose. The data will be juxtaposed with the national elevation network so that differences in surface elevation can be compared.

All studies show that the probability of earthquakes is negligible. The licensing procedure for gas extraction is according to the strictest safety and environmental requirements. Studies show that, in the non-realistic case of an earthquake, there is no impact on inhabited habitats. The reverse burden of proof is specifically laid down for Groningen, but does not apply to other extraction areas.

Gas extraction platform N05-A is located 20 km north of the coastline. Independent research shows that the maximum soil subsidence over 30 years is 2.6 cm at the gas field site. The subsidence bowl does not extend to land.

The Dutch and German EIA  examined all risks. These show that the risks remain negligible and/or far below the norm. Nothing can be ruled out with 100% certainty, but the impact of the unrealistic case that something does happen was also examined in the EIA.

Flaring will be kept to an absolute minimum. A bird watcher will also watch the most suitable moment. Whether the flaring will be visible depends on the time of day, the weather conditions and your position.

Gas is by nature odourless. Gas extraction and drilling is done with electricity and therefore it is not expected that anything can be smelled from the activities over a distance of 20 km. Platform N05-A is electrified with wind energy from wind farm Riffgat.

All studies show that there is no impact on Borkum’s freshwater supply.

ONE-Dyas wants to minimise the discharge of waste materials and has therefore opted for a State-of-the-Art separation of the gas and water followed by an additional activated carbon filter. The remaining waste materials are described in the supplement to the EIA and the permit application. Finally, based on the licence, ONE-Dyas is obliged to investigate whether reinjection of the production water into one of the natural gas fields is possible.

All studies show that the impact on the surrounding area remains (far) below the strict environmental standards. Should pollution nevertheless occur, ONE-Dyas is insured for it.

Prior to the choice of the pipeline route, ONE-Dyas conducted subsurface investigations. This showed that the quality of the soil is good and there is no question of any contamination from Eemshaven. The construction of the pipeline will not result in any additional spread of such contaminants.

Independent researchers from reputable research institutes have come to this conclusion. These results have been assessed by the various consultative bodies and on this basis the Dutch government issued the licence.

This has been examined in the subsidence report prepared by a reputable research institute. The probability is nil. In the unrealistic case of the tremors, there will be no impact on the nearest islands.

The North Sea has many users. The cumulative effects have all been examined in the EIA. This shows that this gas extraction project in the North Sea fits within the spatial planning of the North Sea and that the impact is negligible.

The studies were conducted by independent researchers from well-known, renowned and internationally reputable institutes. In accordance with the law, it is not the taxpayer but the applicant for the licence who bears the cost of these studies. The government and various advisory bodies subsequently review these studies.

There are gas extraction platforms and wind farms at various locations in the North Sea, sometimes just a few kilometres from the coast. Platform N05-A will be located 20 kilometres from the coast. Research shows that its visibility is comparable to that of passing ships. In clear weather, the platform is visible about 30% of the time. The platform is wider and therefore lower than other gas extraction platforms. Its height from the seabed is 37.5 metres and comparable to the transformer station in the Riffgat wind farm, which can be seen off the coast of Borkum.

In June 2022, the Dutch government issued a final licence for this gas development project. Based on this, ONE-Dyas took a final investment decision in September 2022 and started concrete preparations. The schedule is to have the first gas available to German and Dutch households by August 2024. With the German licence, gas can also be extracted from German wells and the potential of natural gas is greater.


The gas will become available to Dutch and German households, and therefore also to Borkum. Borkum is at the centre of the energy transition, with a wind farm just off the coast and a gas extraction project 20 km away. It is conceivable that knowledge of the subsurface and energy transition could be used for energy issues on the island. We are happy to discuss this.

It is good to hear the concerns and questions and exchange views. We do not have the intention to convince people, but we do want to inform everyone as accurately as possible. We have been doing this since 2018 and we want to continue to do so.

Usefulness and necessity of gas

The Netherlands is committed to a CO2-neutral energy supply by 2050. During this energy transition, natural gas will continue to play an important role in the foreseeable future. Dutch natural gas is preferable to importing gas from abroad. It is more sustainable than imported gas, it contributes to the Dutch economy and it means a greater security of supply for our energy.

Platform N05-A will be the first offshore gas production platform in the North Sea to run entirely on wind energy. For this purpose, a cable will be laid to the nearby German wind farm Riffgat. The electrification of platform N05-A with the help of wind energy means a considerable reduction in emissions. Emissions from the production platform will be zero and for the entire project a reduction of 85 percent. With this innovation, ONE-Dyas wants to make a serious contribution to the energy transition.

Obstruction of view

The drilling and production platform will be located about 20 kilometres north of Schiermonnikoog and Borkum. The platform will rise approximately 50 metres above the water surface and, in clear weather, will be visible from Schiermonnikoog and Borkum. The visible size is comparable to the height of passing ships.

Drilling platform (6 July 2017)) seen from Strandpaviljoen de Marlijn, Schiermonnikoog. This temporary drilling platform was at the intended platform location and had a height of 138 meters.

ONE-Dyas wants to reduce the visibility of the offshore infrastructure as much as possible by choosing the lowest possible platform. The intended location offers the best opportunities for drilling multiple gas fields from a single production platform. At the same time, the northern location ensures minimum visibility from the West and East Frisian Islands.

Impact on nature and the environment

Platform N05-A will be the first offshore gas production platform in the North Sea to run entirely on wind energy. The electrification of platform N05-A with the help of wind energy means a considerable reduction in emissions of methane, nitrogen and CO2 . Emissions from the production platform will be zero, and for the entire project we are talking about an 85% reduction.

Oil-based drilling fluid is always transported and processed on land. Drilling cuttings and water-based drilling mud will also transported. The production water is post-treated with an active carbon filter.


The effects are investigated in the Nature Assessment.

Construction phase

The driving of the anchoring piles to install the production platform is the main source of underwater noise. This takes approximately two days.

The driving of the anchor piles requires mitigating measures. To mitigate the effects of underwater noise on marine animals, a bubble screen is installed around the platform during the pile driving. This will lead to a considerable reduction of the underwater noise by 7 to 11 decibels. The noise pollution therefore remains within the Dutch and German standards. ONE-Dyas will keep the option open to apply other noise-reduction techniques, as long as these can reduce the noise by a sufficient number of decibels.

Drilling phase

The most significant noise emissions in the drilling phase are caused by the driving of the conductors (maximum of twelve). The driving of each conductor takes approximately twelve hours. The driving of the conductors comply with the legal standards.

Emissions of pollutants into the sea occur as a result of the activities. These emissions ( spills ) may affect nature. Emissions to water occur mainly during the drilling and production phases.

In the drilling phase, this is water-based drilling mud and cuttings, and in the production phase, the production water that is released during gas treatment. In both phases, the sanitary water and rainwater that washes off the decks is also discharged into the sea. The Mining Regulations sets rules for discharge of pollutants into the sea, such as a maximum oil concentration in discharged water. ONE-Dyas and the operator of the drilling platform ensure that the requirements are met.

No significant effects

Turbidity and sedimentation as a result of the discharge of drilling mud and drill cuttings can have an effect on nature and have been investigated in the Nature Assessment. This study shows that there are no significant effects due to turbidity, because the effect is small and temporary and the area is naturally dynamic. Sedimentation of the drilling mud does not have significant effects either.

The coarse fraction of drilling cuttings will sediment quickly. Per drilling, a maximum layer thickness of approximately 23 cm is expected within a radius of 95 metres from the platform. In twelve drillings, taking the worst-case situation into account, the joint layer thickness of one and a half centimetres is only exceeded within a distance of approximately 105 metres from the discharge pipe. Beyond that, there is no or a negligible amount of additional sedimentation.

ONE-Dyas wants to limit the occurrence and duration of flaring as much as possible. ONE-Dyas, therefore, wants to use the treatment process as much as possible to test newly drilled gas fields after drilling. If flaring is necessary, a birdwatcher is called in to advise on the appropriate time for flaring. Flaring is, as much as possible, done during the day. This protocol is applied by ONE-Dyas by default and so far there have been no incidents with birds.

Gas extraction and nature development need not be mutually exclusive. No other activity may take place within 500 metres surrounding a drilling platform. This means, for example, that no shipping or (trawl) fishing is allowed. This allows marine life to develop undisturbed. The platform provides a hard substrate on which flora and fauna (including shellfish) can develop. Together with nature organisations, ONE-Dyas wants to draw up a monitoring proposal for new research.

At the end of the extraction process, all boreholes will be decommissioned.

There are two possibilities:

  1. suspend – the borehole is closed off with a valve.
  2. abandonment – putting mechanical and cement plugs at various heights in the borehole. Then the plugs and the conductor are cut off and removed 6 metres below the seabed.

When extraction is complete, all the boreholes are capped. The platform is removed, its anchoring posts are cut away and removed 6 metres below the seabed. This ensures that no fishing gear can get stuck behind them. ONE-Dyas first writes a work plan for this, which must be approved by the State Supervision of Mines. Everything is returned to its original state, which is generally better than before due to the nature development that has taken place.

The choice of location for the platform takes into account other uses. ONE-Dyas is aware of the effects the project may have on the environment and wants to be a reliable partner and good neighbour. This is achieved, among other things, by ensuring that the activities fit in as well as possible with the (other activities in the) surroundings. All this is done in the safest and most responsible way for both people and nature. ONE-Dyas is committed to proactively seeking dialogue and possible cooperation with stakeholders.

Cumulation test

The research in the cumulation test shows that there are no significant effects due to cumulation of effects of the intended activity N05-A with the effects of other activities that (may) take place in the future. To prevent cumulative effects with future projects of ONE-Dyas itself, ONE-Dyas will ensure that no cumulation of underwater noise occurs during the (simultaneous) implementation of the projects.

Soil subsidence

The intended soil subsidence caused by gas production is estimated to be less than 5 centimetres at the deepest point of the subsidence basin after completion of the production phase. TNO and SodM endorse this calculation and indicate that the soil subsidence basin lies entirely in the North Sea and that the soil subsidence will not affect the Wadden Islands and the mainland.

The geological composition of the GEMS area and the gas reservoir consists of good permeable sandstone. It probably will not be necessary to use fracking. The technology used in such cases, including the possible application of hydraulic stimulation, is described in the extraction plan.

The intended seismic risk from gas production is negligible for gas fields N05-A and N05-A-North, which thus fall in the lowest seismic risk category (SRA Cat. I). TNO and SSM endorse this assessment. The Tanzanite-Oost gas field has a probability of trembling of 19%, but on the basis of a more detailed analysis data is also classified in the lowest seismic risk category. Because of the low negligible seismic risk and the large distance to the Wadden (islands) and the mainland, no detrimental effects and damage as a result of soil vibration are expected from this gas production.


Shipping is prohibited within a zone of 500 metres around a platform. ONE-Dyas always conducts several safety studies for new and existing activities, including a study of the risks of collision with ships. The MARIN study, which is appended to the EIA, shows that the probability of a collision with the platform (worst-case approach) has been calculated at 1 / 273 years. All platforms are equipped with an Automatic Identification of Shipping System. (AIS system). This is a type of anti-collision system that raises the alarm well in advance of an approaching ship and thus a possible collision. The use of AIS reduces the chance of a collision, which in the worst case is calculated at once in 273 years, by another 75%.

The project area is located in a moderately trafficked part of the North Sea and is also used for shipping and fishing. A few kilometres north of the intended location of the platform is the Terschelling-German Bight shipping route. No shipping or other use is allowed in a zone of 500 metres around the platforms. This causes local restrictions for fishery, shipping and recreation (sailing). Within this safety zone, dragging fishing nets over the seabed and in the water column is not allowed either. The choice of location for the platform takes shipping and other uses into account. The platform will be equipped with the required navigation lights and collision prevention systems.