Questions and answers Information meeting gas extraction and subsidence

This approach is difficult because it involves several disciplines and involves a long chain of calculations. So assessing the damage cannot always be done integrally. However, in cases with a trigger, such as subsidence caused by gas extraction, the context will be included. After all, gas extraction is a major cause of subsidence, especially in areas such as Groningen and Tytsjerksteradiel. An integral study then seems necessary.

Soil subsidence caused by gas extraction affects the water table. This is called the "relative groundwater level. With subsidence, groundwater does not sink with the soil and therefore comes closer to the surface. Soil subsidence is thus a combination of factors: Gas extraction causes subsidence, the effect of which is to change the relative water table.

Direct damage from gas extraction itself is negligible. Damage that occurs in the context of gas extraction is often caused indirectly. This usually occurs in the shallow subsurface, for example through changes in groundwater levels or water management. In some cases, the water board applies level lowering. These indirect effects can lead to damage, but are related to the subsidence caused by gas extraction.

Indeed, the size of a gas field affects the relative displacements (movement) of the soil. In a large gas field, the soil differences between them are smaller, meaning the displacements are less. Smaller fields contain less gas, causing subsidence. However, because fields are more localized, the relative displacements in that particular area may be relatively larger. Overall, however, the impact remains limited.

Certainly. Given the situation in Groningen, we understand the concerns when activities take place in the deep subsurface. That's why we assess each initiative individually, based on the specific circumstances. This involves looking at the entire context. The necessary expertise is deployed to carefully map the expected effects. The Minister approves an extraction plan only when it is really safe to do so.

See answer to the next question.

It is the responsibility of the Wetterskip to determine how they handle the management of groundwater levels. If the Wetterskip wants to handle it in a different way, we will take that into account. In that case, we will have to review what is and what is not possible. The consultants will then assess the effects, including the impact on the water table. 

For this, the ministry has established an assessment framework.

Assessment framework for extraction plans

• Assessment based on the following aspects:
  • Planned subsurface management.
  • Projected land subsidence.
  • The expected seismic risk.
  • The possible effects of soil movement on people, buildings and infrastructure.
  • There are adverse effects on nature and the environment.
• Permit/consent only if it can be done safely.

No risk does not actually exist. We can never guarantee safety 100 percent of the time. You always consider as many factors as possible. When you do something there is always a possible effect or consequence. It is important to see what risk category something falls into, for example, whether the risk is negligible or whether only cosmetic damage is to be expected.

There can be several reasons for denying a permit. One example is when the seismic risk, such as the likelihood of earthquakes, becomes too great. This is the reason for not granting a permit in Groningen, for example.

In the permit application, the ministry assesses only the subsidence estimated as a result of gas extraction. We do not consider subsidence caused by peat sinking or oxidation. 

Surface subsidence caused by peat sinking or water level lowering by water boards, which exposes peat to air and causes further subsidence, is outside our assessment. We focus only on the effects of gas extraction.

This is the responsibility of Vermilion. They are responsible for compensating the costs and damage caused by gas extraction. This is assessed in Friesland by the Soil Subsidence Committee for Natural Gas Production Fryslân.

The Netherlands wants to become climate neutral by 2050. There will be a gradual switch from fossil to renewable energy. At the moment, there is insufficient sustainable energy available. 80% of households still use natural gas, as does much of Dutch industry. By extracting gas in the Netherlands, we are less dependent on other countries. It also causes less CO₂ emissions than imported gas during extraction and transportation.

In the Netherlands, gas is extracted from some 200 gas fields. This contributes 30% of national gas consumption. 

In Friesland, we have the Committee on Subsidence in Natural Gas Production Friesland (CBAF), which any government agency can join. If measures are needed because the municipality, the water board or the province has to carry out repairs and Vermilion is the causer or joint causer, they can submit a claim to the committee. The Committee will then give a binding recommendation as to what portion of the costs will be borne by the gas producer. This damage will then actually be compensated.

Mining companies no longer have a role in the claims chain. In filing, assessment and settlement, both Vermilion and NAM are outside the damage settlement process. The only role they still have is when there is a verdict and the reporter is proven right. In that case, Vermilion must compensate the damage, and Vermilion has committed to do so.

Vermilion is preparing a new extraction plan for a small field in the area that involves water-related issues. There have been intensive preliminary consultations with the water board* to see exactly how that is. 

*This consultation, however, took place before the Wetterskip adopted the new position.

72 cents of every euro goes to the Minister of Finance (currently even slightly more, 82 cents, because of the levy related to the energy crisis). So part of it goes to the gas extraction company and another part to the government, where it goes into the general funds and is used for the budget of the Netherlands.

We are now looking with the mining companies at how we handle the likes and dislikes in the future.

There are 2 types of baseline measurements:

1. Zero measurements were long prescribed in the extraction plan, with Vermilion responsible for carrying out zero measurements at various locations. The ministry, partly on the advice of experts, stopped including this condition because in the case of damage, the causal link between the damage and the activity must always be demonstrated as well. This role now lies with the Mining Damage Commission or CABF.
2. When Vermilion has heavy transports performed - as with TID-200 - truck traffic vibrations are considered and zero measurements of infrastructure and buildings are still taken.

It is good to know that this has existed. You can have a nice overview of the damage now and before, but this only says nothing about the causes. Whether or not there has been a baseline measurement, it is always important to first investigate whether something has happened underground that could have caused the mining damage. If it is possible within the wide margins, we have experts carefully examine each crack.

An expert can also prove that an earthquake (due to mining) aggravated existing damage. If it cannot be determined that the damage was caused by other causes and we have seen in the soil that something was going on (such as an earthquake, for example), the decision usually falls in favor of the claimant.

Doesn't say much. In 4 years there have been 500 reports. About 50 related to Ekehaar, Drenthe. This is the first time the commission has found that damage was caused or aggravated by a mining-related quake in October 2023. This resulted in 14 cases being awarded compensation ranging between €800 and €16,000. Due to subsidence, no (direct) mining-related damage has yet been identified anywhere.