5.2.1 Regulatory regime for site remediation in Europe

The EU CCS DirectiveDirective 2009/31/EC of the European Parliament and of the Council of 23 April 2009 on the geological storage of carbon dioxide (2009) and its Guidance Documents 1 and 2 (ECEuropean Commission, 2011a, b) represent the principal regulatory regime for all EUEuropean Union Member States in relation to the geological storage(CO2) A process for retaining captured CO2, so that it does not reach the atmosphere of carbon dioxide, although additional regional and local regulations may exist in the Member States.

In terms of reasons for site remediation, the CCSCarbon dioxide Capture and Storage Directive defines:

• Leakage(in CO2 storage) The escape of injected fluid from the storage formation to the atmosphere or water column: any release of CO2Carbon dioxide from the storage(CO2) A process for retaining captured CO2, so that it does not reach the atmosphere complex (storage(CO2) A process for retaining captured CO2, so that it does not reach the atmosphere site and surrounding geological domain, which can have an effect on overall storage(CO2) A process for retaining captured CO2, so that it does not reach the atmosphere integrity and security; that is, secondary storage(CO2) A process for retaining captured CO2, so that it does not reach the atmosphere containments).
• Significant irregularityAny irregularity in the injection or storage operation or in the condition of the storage volume itself, which implies the risk of a leakage or risk to the environment or human health: any irregularity in the injectionThe process of using pressure to force fluids down wells or storage(CO2) A process for retaining captured CO2, so that it does not reach the atmosphere operations or in the condition of the storage(CO2) A process for retaining captured CO2, so that it does not reach the atmosphere complex itself, which implies the riskConcept that denotes the product of the probability of a hazard and the subsequent consequence of the associated event of a leakage(in CO2 storage) The escape of injected fluid from the storage formation to the atmosphere or water column or riskConcept that denotes the product of the probability of a hazard and the subsequent consequence of the associated event to the environment or human health.

The EU CCS DirectiveDirective 2009/31/EC of the European Parliament and of the Council of 23 April 2009 on the geological storage of carbon dioxide requires that a corrective measures plan is prepared by the operator and submitted as part of the storage(CO2) A process for retaining captured CO2, so that it does not reach the atmosphere permit application, which should be "ready to use" (in the sense described by Kuuskraa and Godec, 2007) immediately in case of leakage(in CO2 storage) The escape of injected fluid from the storage formation to the atmosphere or water column or significant irregularities. Article 16 of the CCSCarbon dioxide Capture and Storage Directive describes the measures that should be taken in case of leakage(in CO2 storage) The escape of injected fluid from the storage formation to the atmosphere or water column or significant irregularities and states that Member States shall ensure:

• That in the event of leakages or significant irregularities, the operator immediately notifies the competent authority, and takes the necessary corrective measures, including measures related to the protection of human health. In cases of leakages and significant irregularities which imply the riskConcept that denotes the product of the probability of a hazard and the subsequent consequence of the associated event of leakage(in CO2 storage) The escape of injected fluid from the storage formation to the atmosphere or water column, the operator shall also notify the competent authority pursuant to the EUEuropean Union ETSEmissions Trading System, defined in the EU ETS Directive 2003/87/EC amended by Directive 2009/29/EC Directive (2003).
• The corrective measures referred above shall be taken as a minimum on the basis of a corrective measures plan submitted to and approved by the competent authority in the application permit.
• The competent authority may at any time require the operator to take the necessary corrective measures, as wellManmade hole drilled into the earth to produce liquids or gases, or to allow the injection of fluids as measures related to the protection of human health. These may be additional to or different from those laid out in the corrective measures plan. The competent authority may also at any time take corrective measures itself.
• If the operator fails to take the necessary corrective measures, these measures shall be taken by the competent authority, which shall recover the costs from the operator including by drawing on the financial security pursuant to Article19 of the EU CCS DirectiveDirective 2009/31/EC of the European Parliament and of the Council of 23 April 2009 on the geological storage of carbon dioxide.

Corrective measures are actions, measures or activities taken to correct significant irregularities or to close leakages in order to prevent or stop the release of CO2Carbon dioxide from the storage(CO2) A process for retaining captured CO2, so that it does not reach the atmosphere complex. Intended to ensure the safety and effectiveness of geological storage(CO2) A process for retaining captured CO2, so that it does not reach the atmosphere, corrective measures are part of the overall riskConcept that denotes the product of the probability of a hazard and the subsequent consequence of the associated event management process. They ensure the safety of geological storage(CO2) A process for retaining captured CO2, so that it does not reach the atmosphere and manage the risks from leakage(in CO2 storage) The escape of injected fluid from the storage formation to the atmosphere or water column during the project life cycle. Corrective measures, as mentioned in the Guidance Document 2 (ECEuropean Commission, 2011b), should be:

• RiskConcept that denotes the product of the probability of a hazard and the subsequent consequence of the associated event based; linked to identified risks from site and complex characterization (and risk assessmentA process intended to calculate or estimate the risk to a given target, part of a risk management system) and subject to the limitations of available technologies;
• Specific to the storage(CO2) A process for retaining captured CO2, so that it does not reach the atmosphere site and complex;
• Suitable for use to address leakage(in CO2 storage) The escape of injected fluid from the storage formation to the atmosphere or water column or significant irregularities from identified leakage(in CO2 storage) The escape of injected fluid from the storage formation to the atmosphere or water column pathways and specific leakage(in CO2 storage) The escape of injected fluid from the storage formation to the atmosphere or water column mechanisms out of the storage(CO2) A process for retaining captured CO2, so that it does not reach the atmosphere complex and any leakage(in CO2 storage) The escape of injected fluid from the storage formation to the atmosphere or water column to the surface;
• Closely linked to monitoringMeasurement and surveillance activities necessary for ensuring safe and reliable operation of a CGS project (storage integrity), and for estimating emission reductions plans and monitoringMeasurement and surveillance activities necessary for ensuring safe and reliable operation of a CGS project (storage integrity), and for estimating emission reductions, which should provide triggers for use of corrective measures by identification of leakage(in CO2 storage) The escape of injected fluid from the storage formation to the atmosphere or water column or irregularities;
• Used when there is any leakage(in CO2 storage) The escape of injected fluid from the storage formation to the atmosphere or water column or significant irregularities.

MonitoringMeasurement and surveillance activities necessary for ensuring safe and reliable operation of a CGS project (storage integrity), and for estimating emission reductions and corrective measures are closely interlinked and the plans and activities should be developed by the operator in a wholesome manner along with the risk assessmentA process intended to calculate or estimate the risk to a given target, part of a risk management system. The competent authority should seek to ensure close integration between these measures.

The deployment of corrective measures is required in the event of leakages or significant irregularities, and would usually be detected by monitoringMeasurement and surveillance activities necessary for ensuring safe and reliable operation of a CGS project (storage integrity), and for estimating emission reductions results or inspections. In addition monitoringMeasurement and surveillance activities necessary for ensuring safe and reliable operation of a CGS project (storage integrity), and for estimating emission reductions is used to assess the effectiveness of corrective measures. Additional monitoringMeasurement and surveillance activities necessary for ensuring safe and reliable operation of a CGS project (storage integrity), and for estimating emission reductions activities may be required in event of any leakage(in CO2 storage) The escape of injected fluid from the storage formation to the atmosphere or water column or significant irregularities.

Corrective measures may be used at any stage in the life cycle after storage(CO2) A process for retaining captured CO2, so that it does not reach the atmosphere permit award and are expected to be used mostly during the operations (injectionThe process of using pressure to force fluids down wells) phase and post-closurePeriod after transfer of responsibility to the competent authority pre-transfer phase. After transfer of responsibilityTransfer of all rights and obligations associated with a storage site to a designated authority; will normally be granted when the obligations in the site closure permit has been met with an adequate level of confidence, corrective measures may still be required, although the likelihood is reduced from then on as the CO2 plumeDispersing volume of CO2-rich phase contained in target formation reaches stability.

Under normal operating conditions, in the event of leakages or significant irregularities, the operator has to immediately notify the competent authority both under the EU CCS DirectiveDirective 2009/31/EC of the European Parliament and of the Council of 23 April 2009 on the geological storage of carbon dioxide (2009) and the EUEuropean Union ETSEmissions Trading System, defined in the EU ETS Directive 2003/87/EC amended by Directive 2009/29/EC Directive (2003) and take the necessary corrective measures, including measures related to the protection of human health. Measures approved in the corrective measures plan shall be taken as a minimum.

Initial plans will be based on the risks identified for the storage(CO2) A process for retaining captured CO2, so that it does not reach the atmosphere complex, with predicted pathways and scenarios for potential leakage(in CO2 storage) The escape of injected fluid from the storage formation to the atmosphere or water column based on site characterization and modelling. The types of riskConcept that denotes the product of the probability of a hazard and the subsequent consequence of the associated event and pathways would likely be similar to generic types of pathways that are described in Guidance Document 1 (ECEuropean Commission, 2011a), primarily either geological pathways (e.g. faults, fractures or caprockRock of very low permeability that acts as an upper seal to prevent fluid flow out of a reservoir absence), manmade pathways (i.e. wellManmade hole drilled into the earth to produce liquids or gases, or to allow the injection of fluids bores or old mine workings) or the other types of riskConcept that denotes the product of the probability of a hazard and the subsequent consequence of the associated event (e.g. groundwater contamination, displaced oil and gas, subsidence). The general locations of many potential pathways can be predicted ahead of any leakage(in CO2 storage) The escape of injected fluid from the storage formation to the atmosphere or water column situation, e.g. the location of a major fault(geology) A surface at which strata are no longer continuous, but are found displaced or a wellboreThe physical hole that makes up the well, it can be cased, open, or a combination of both; open means open for fluid migration laterally between the wellbore and surrounding formations; cased means closing of the wellbore to avoid such migration. However, some potential leakage(in CO2 storage) The escape of injected fluid from the storage formation to the atmosphere or water column pathways may not be detectable (e.g. sandstoneSand that has turned into a rock due to geological processes intrusions) with current technologies at the time of initial risk assessmentA process intended to calculate or estimate the risk to a given target, part of a risk management system and corrective measureMeasure taken to correct (remediate) significant irregularities or to prevent or stop leakages of CO2 from the storage volume plans or their locations may be uncertain. If these emerge subsequently, site characterisation, risk assessmentA process intended to calculate or estimate the risk to a given target, part of a risk management system, monitoringMeasurement and surveillance activities necessary for ensuring safe and reliable operation of a CGS project (storage integrity), and for estimating emission reductions and corrective measures plans will need to be updated as necessary.

The operator and competent authority should consider that the actual and specific location of any significant irregularityAny irregularity in the injection or storage operation or in the condition of the storage volume itself, which implies the risk of a leakage or risk to the environment or human health or leakage(in CO2 storage) The escape of injected fluid from the storage formation to the atmosphere or water column will usually not be known before it is detected, nor will the actual pathway between the leak and the surface if the flow is not direct (which may be the case as a leak may involve a complex three dimensional problem combining the geology and wellManmade hole drilled into the earth to produce liquids or gases, or to allow the injection of fluids pathways). The corrective measures will ultimately need to be specific to the actual leakage(in CO2 storage) The escape of injected fluid from the storage formation to the atmosphere or water column or significant irregularityAny irregularity in the injection or storage operation or in the condition of the storage volume itself, which implies the risk of a leakage or risk to the environment or human health, taking into account the precise location and nature of the leakage(in CO2 storage) The escape of injected fluid from the storage formation to the atmosphere or water column or irregularity, and the specific situation and circumstances in which the leak occurred. Flexibility is required to update and change the plan according to the specific situation.

Early warning and early intervention in the detection of significant irregularities will urge to take action through corrective measures to prevent the situation getting worse, and reduce the riskConcept that denotes the product of the probability of a hazard and the subsequent consequence of the associated event of actual leakage(in CO2 storage) The escape of injected fluid from the storage formation to the atmosphere or water column from the storage(CO2) A process for retaining captured CO2, so that it does not reach the atmosphere complex. In the event of a leakage(in CO2 storage) The escape of injected fluid from the storage formation to the atmosphere or water column or significant irregularityAny irregularity in the injection or storage operation or in the condition of the storage volume itself, which implies the risk of a leakage or risk to the environment or human health the operator must immediately notify the competent authority and take the necessary corrective measures, including measures related to the protection of human health. The competent authority needs to ensure the immediate implementation of correctives measures as a minimum on the basis of the presented corrective measures plan. Handling and implementing corrective measures in the event of actual leakage(in CO2 storage) The escape of injected fluid from the storage formation to the atmosphere or water column to surface will require rapid and effective interaction between the competent authority and operator. It will require strong technical expertise in drilling, wellManmade hole drilled into the earth to produce liquids or gases, or to allow the injection of fluids engineering and geosciences. Specialist consultants would often be involved in comparable situations in the oil and gas industry. competent authorities will need to know what expertise exists within their organizations and where and when to draw on external experts.

Corrective measures can be applied to two major types of pathways: (1) to the natural, geological system and (2) to the engineered, wellboreThe physical hole that makes up the well, it can be cased, open, or a combination of both; open means open for fluid migration laterally between the wellbore and surrounding formations; cased means closing of the wellbore to avoid such migration system. While technically it is feasible to implement corrective measures and repairs, in general, their effectiveness and potential to restore the geological system is considered limited. In principle, the wellManmade hole drilled into the earth to produce liquids or gases, or to allow the injection of fluids can be accessed, allowing tools to be run or operations to be performed in order to repair leakages or irregularities of the wellboreThe physical hole that makes up the well, it can be cased, open, or a combination of both; open means open for fluid migration laterally between the wellbore and surrounding formations; cased means closing of the wellbore to avoid such migration and its immediate surroundings. Wells actually are the only direct connection to the subsurface. Flaws in the geological system can typically be corrected only when wells are penetrating the affected zone. Nevertheless, geological anomalies may often reflect three-dimensional problems, significantly extending the vertical and/or lateral directions, rather than giving a localized problem. This reduces the number of options to repair the issue. Corrective measures involving early interventions and modifications to injectionThe process of using pressure to force fluids down wells operations will usually be beneficial and can provide effective riskConcept that denotes the product of the probability of a hazard and the subsequent consequence of the associated event management in some circumstances. The Guidance Document 2 (ECEuropean Commission, 2011b) and the Aspen Report (Arts et al., 20092009 - R. Arts, van den Belt F., Benedictus T., Blom M., A. de Buck, H. Croezen, C. Hofstee, Ch. Kolesar, T. Koryl, M. Lewitt, M. Nepveu, H. Stoiber, S. Wartmann, T. WildenborgSupport to the Introduction of the Enabling Legal Framework on Carbon Dioxide Capture and Storage (CCS)see more) summarise some of the corrective measures methods both for geological system and wells.

Managing injectionThe process of using pressure to force fluids down wells rates, locations and pressures can be used to manage some of the risks relating to geological leakage(in CO2 storage) The escape of injected fluid from the storage formation to the atmosphere or water column pathways and risks. However, many of the other technologies for managing issues related to geological pathways are more novel and also uncertain. Technique effectiveness involving new wells that intersect with plumes or pathways will depend on being able to identify the target area, which may be difficult in a three dimensional space. Other techniques with extraction of either CO2Carbon dioxide or water are technically plausible but handling the produced fluids and undertaken costs will need to be evaluated on a case by case basis. We should take into consideration that:

• Any corrective measures will be highly specific and need to take account the nature, flux and location of the leakage(in CO2 storage) The escape of injected fluid from the storage formation to the atmosphere or water column or irregularity (in three dimensions), which may be poorly understood especially for geological pathways.
• Gathering further data through monitoringMeasurement and surveillance activities necessary for ensuring safe and reliable operation of a CGS project (storage integrity), and for estimating emission reductions and re-evaluation of site characterization and modelling is essential.
• Corrective measures for dealing with leakage(in CO2 storage) The escape of injected fluid from the storage formation to the atmosphere or water column or significant irregularities from wells are generally considered feasible using techniques and practices from the oil and gas industry or gas storage(CO2) A process for retaining captured CO2, so that it does not reach the atmosphere.
• Managing injectionThe process of using pressure to force fluids down wells rates, locations and pressures can be used to manage some of the risks relating to geological leakage(in CO2 storage) The escape of injected fluid from the storage formation to the atmosphere or water column pathways and risks.
• Other approaches involving extraction of CO2Carbon dioxide or water are possible but the fluids produced will need to be handled and the costs may be high.
• The costs of any corrective measures will be highly uncertain and specific to the leakage(in CO2 storage) The escape of injected fluid from the storage formation to the atmosphere or water column or irregularity being addressed.

CAs should be aware that the status of the technologies that may be used for corrective measureMeasure taken to correct (remediate) significant irregularities or to prevent or stop leakages of CO2 from the storage volume is highly variable. Virtually none of the technologies have yet been used in CO2Carbon dioxide storage(CO2) A process for retaining captured CO2, so that it does not reach the atmosphere applications or environments.

The EU CCS DirectiveDirective 2009/31/EC of the European Parliament and of the Council of 23 April 2009 on the geological storage of carbon dioxide requires that the corrective measures plan be based on the risk assessmentA process intended to calculate or estimate the risk to a given target, part of a risk management system. For risks identified during the risk assessmentA process intended to calculate or estimate the risk to a given target, part of a risk management system, corrective measures have to be developed and described in the corrective measures plan. Currently, such measures are available only for certain kinds of risks. In some cases, only very generic measures like reducing reservoirA subsurface body of rock with sufficient porosity and permeability to store and transmit fluids pressure or aborting injectionThe process of using pressure to force fluids down wells are currently proposed.

The corrective measures plan has to be handed in as part of the storage(CO2) A process for retaining captured CO2, so that it does not reach the atmosphere permit application. Detailed corrective measures have to be developed before injectionThe process of using pressure to force fluids down wells has started. It can be assumed that, in case a riskConcept that denotes the product of the probability of a hazard and the subsequent consequence of the associated event materializes, it has to be assessed, whether the foreseen corrective measureMeasure taken to correct (remediate) significant irregularities or to prevent or stop leakages of CO2 from the storage volume is suitable, or whether changes to the measures are needed. Over the lifetime of a storage(CO2) A process for retaining captured CO2, so that it does not reach the atmosphere site new corrective measures might emerge or the approach in measures might change. Furthermore, with increased experience about the storage(CO2) A process for retaining captured CO2, so that it does not reach the atmosphere site, risks might be considered irrelevant or new risks might. It thus seems advisable to regularly update the corrective measures plan. This could be in line with the timeframe for regular updating of the monitoringMeasurement and surveillance activities necessary for ensuring safe and reliable operation of a CGS project (storage integrity), and for estimating emission reductions plan.

The Guidance Document 2 (ECEuropean Commission, 2011b) and the Aspen Report (Arts et al., 20092009 - R. Arts, van den Belt F., Benedictus T., Blom M., A. de Buck, H. Croezen, C. Hofstee, Ch. Kolesar, T. Koryl, M. Lewitt, M. Nepveu, H. Stoiber, S. Wartmann, T. WildenborgSupport to the Introduction of the Enabling Legal Framework on Carbon Dioxide Capture and Storage (CCS)see more) propose a possible format for the corrective measures plan aiming to enhance transparency and comparability as wellManmade hole drilled into the earth to produce liquids or gases, or to allow the injection of fluids as exchange of information with regards to corrective measures plan. It consists of two parts. In the first section (Tab. 5-1) an overview is given on the corrective measures to be taken for the risks identified. Threshold values or qualitative circumstances are stated, which will trigger the implementation of a corrective measureMeasure taken to correct (remediate) significant irregularities or to prevent or stop leakages of CO2 from the storage volume. Furthermore, the monitoringMeasurement and surveillance activities necessary for ensuring safe and reliable operation of a CGS project (storage integrity), and for estimating emission reductions methods used to monitor the effectiveness of a corrective measureMeasure taken to correct (remediate) significant irregularities or to prevent or stop leakages of CO2 from the storage volume are named together with the number of the method from the monitoringMeasurement and surveillance activities necessary for ensuring safe and reliable operation of a CGS project (storage integrity), and for estimating emission reductions plan (used for easier identification of methods throughout the plan). In the second part of the plan (Tab. 5-2), each corrective measureMeasure taken to correct (remediate) significant irregularities or to prevent or stop leakages of CO2 from the storage volume is described in detail with regards to the timeframe needed for implementation and the detailed activities to be carried out. Furthermore, a rationale is to be delivered, why the corrective measureMeasure taken to correct (remediate) significant irregularities or to prevent or stop leakages of CO2 from the storage volume is appropriate for the riskConcept that denotes the product of the probability of a hazard and the subsequent consequence of the associated event it is related to.