Accessing Scotland's geothermal resource: regulatory guidance

Health and safety

There are no regulations specific to the drilling of an onshore borehole (well) for the purposes of exploring and exploiting the geothermal resource, except when the drilling takes place within one kilometre of a mining area (see later section on permission to access land and property). Existing regulations apply only to boreholes (wells) drilled with a view to the extraction of petroleum. However, the broad framework of the Health and Safety at Work etc Act 1974 (HSW Act), which applies to all workplaces, applies to geothermal boreholes (wells) and well operations. HSE Inspectors will ascribe the principles of specific regulations, standards and guidance as representing relevant good practice through which the operator, as dutyholder, can demonstrate compliance with the HSW Act.

This approach will involve ensuring that operators drilling boreholes (wells) voluntarily follow the Borehole Sites and Operations Regulations 1995 (BSOR), and the Offshore Installations and Wells (Design and Construction, etc) Regulations 1996 (DCR), as the basis for their approach to managing, and controlling, the risks associated with the drilling and operation of geothermal boreholes (wells). HSE has specialist inspectors who inspect onshore and offshore wells and borehole construction and operations. This includes boreholes drilled for geothermal energy.

If enforcement action is required to be taken for the construction and operation of a geothermal borehole (well), it will be conducted under the HSW Act, with the principles of DCR, BSOR, and the standards and guidance associated with these regulations in determining the risk gap and subsequent level of enforcement. HSE will also expect the voluntary adoption of the specific requirements within DCR and BSOR to be followed, such as notification, the production of a health and safety document, weekly well reports and the appointment of an independent well examiner.

Just as with boreholes drilled for hydrocarbons, HSE inspectors will expect operators of geothermal projects to maintain a life cycle approach to the management of the well. That means ensuring that a well is designed, modified, commissioned, constructed, equipped, operated, maintained, suspended and abandoned that, so far as is reasonably practicable, there can be no unplanned escape of fluids from the well. In addition, ensuring that risks to the health and safety of persons from it, or anything in it, or in strata to which it is connected are as low as is reasonably practicable.

Construction projects

The Construction (Design and Management) Regulations 2015 (CDM) define a system of management roles and processes and prescribe a large number of practical health and safety precautions and welfare requirements for construction projects. The roles are:

• the client (the person for whom the project is carried out)
• the principal contractor (persons who co-ordinate health and safety during the pre-construction and construction stages of the project respectively)
• contractors (persons who carry out the construction work)
• the principal designer (the person who designs structures to be constructed by the contractors)

Additionally, CDM impose duties on the self-employed, in recognition of the high degree of self-employment in the construction industry.

These regulations are intended to protect persons from health and safety risks arising from construction work through the establishment of a systematic framework for management of those risks.

The law applies to the whole construction process, on all construction projects, from concept to completion.

The HSE must be notified of a construction project before the construction phase begins, if the construction work on a site is scheduled to last longer than 30 working days and have more than 20 workers working simultaneously at any point in the project, or if the construction work is scheduled to exceed 500 person days.

Provisions within CDM include, but are not limited to:

• safe places of construction work
• demolition or dismantling
• explosives
• excavations
• prevention of risk from fire, flooding or asphyxiation
• traffic routes
• vehicles
• emergency procedures
• fire detection and fire fighting
• fresh air

Boreholes

BSOR require operators of geothermal projects which are 30 metres deep, or more, inside a mining area, to notify the HSE of:

• the commencement of drilling within 30 days, and of any material changes to the name and address of the person entitled to drill the borehole
• the Ordnance Survey National Grid reference of the location of the top of the borehole
• its directional path
• its terminal depth and location and a description of the operation performed and programme of works

A mining area means land which lies within one kilometre of the workings of any mine whether currently being worked or disused, or land in relation to which a licence to mine minerals has been granted.

Operators should consult with knowledgeable bodies and authorities, such as the CA and the British Geological Survey (BGS), mineral owners, mine owners, the owners of other underground structures, facilities or boreholes and other sources of relevant information which will allow them to assess the effect which a borehole operation is likely to have on other persons.

Operators using BSOR as a framework to demonstrate compliance with the HSW Act should ensure constant site supervision by a competent person able to maintain the safety of the well. Operators have a duty to co-ordinate their work and their safety measures with those of other employers and self-employed persons on site. They will also be required to ensure that a sufficient number of competent persons are provided with a view to enabling those operations can be carried out safely.

Borehole operations should be planned, and organised, from the outset with health and safety in mind. Operators should ensure that operations do not commence until a health and safety document has been prepared. The document should be appropriate to the hazards of the operation to which it applies.

The health and safety document should demonstrate that the risks to employees at the borehole site have been determined, and assessed, and that adequate measures will be taken to safeguard their health and safety. The health and safety document should also, where appropriate, include plans suitable for the particular site and operations carried out there. Good co-ordination of the work of contractors is essential for safe working. Borehole sites during drilling, and workover operations particularly, become compact areas of high activity. The co‑ordination of work at the site is aimed at planning, organising and controlling the programme of work and the contributions made by various contractors so that they may be conducted with risks to health and safety reduced to as low as is reasonably practicable. Suitable well control equipment will also be required to be provided, and deployed, during borehole operations to protect against blowouts. The operator will also be required to determine if those personnel working at the borehole site may be exposed to atmospheres hazardous to their health.

Local factors should be considered, such as:

• the proximity of highways
• rights of way
• buildings
• housing
• woodland
• crops
• any other matters which may affect the safety of the site

Where necessary the relevant authorities should be consulted. Sites should be located and be of suitable size and layout to allow hazards to be confined within the site boundaries. Consideration should be given to the need for site security to minimize hazards from, and to, persons other than those authorised to be on the site. The area of land given to a site should allow adequate space for suitable siting of equipment.

Consideration should also be given to the risks of displacing pressurised gases such as carbon monoxide or methane from coal strata or mine workings into nearby receptor premises. More information is available in Guidance on managing the risk of hazardous gases when drilling or piling near coal .

Emergency services should be informed of the location of borehole sites, access routes from public roads and the nature of the operations and circumstances which they may be called upon to attend. Provision should be made for suitable rendezvous and forward control points with sufficient suitable parking space for emergency vehicles close to the site. The health and safety document should include arrangements and plans for escape and rescue and fire and explosion protection.

The health and safety document should be kept up to date. It should be reviewed if any relevant changes occur to the site, or operations, carried out there. Operators have a duty to ensure that the health and safety document is made available to each employer who has employees at work on the site.

Operators should also ensure that all workplaces on a borehole site are designed, constructed, erected and maintained in provision of sufficient stability and protection of employees and to withstand anticipated environmental forces on site.

Borehole records

The Water (Scotland) Act 1980 requires anyone proposing to sink a well, or drill a borehole to a depth greater than 15 metres (50 feet), for the purpose of searching for, or abstracting, water to notify the Natural Environment Research Council (as represented by the BGS). In addition, a record must be kept of the progress of the work. On completion, or abandonment, of the work, the record must be deposited with the BGS’ National Geoscience Data Centre along with details of any test made before completion or abandonment, specifying the flow of water and, where practicable, the water levels during the test and thereafter until the water returned to its natural level. All borehole logs are accepted, and welcomed, by the National Geoscience Data Centre, not just those required under the Water (Scotland) Act.

Well integrity

The DCR are mostly concerned with the integrity of onshore and offshore wells which are drilled with a view to the extraction of petroleum. The general duty of the well operator is that they must ensure the integrity of the well for its entire lifecycle such that, so far as is reasonably practicable, there can be no unplanned escape of fluids from the well, and that risks to the health and safety of persons from it, or anything in it or in strata to which it is connected, are as low as is reasonably practicable. In the pre-design stage, the well-operator is required to take all appropriate steps to obtain predictions of the sub-surface environment to be experienced within. As far as is reasonably practicable, all potential hazards and circumstances likely to lead to unsafe well conditions should be identified by the well operator. In the post-design stage, the well operator should ensure sufficient measures are taken of well conditions and sub-surface properties.

The design and construction of the well should account for the health and safety of those tasked with suspending or abandoning it and for the continued integrity of the well after its suspension and/or abandonment. This will prevent unplanned escapes of fluids from its reservoir. Many elements of suspension and abandonment can only be decided at the time of suspension or abandonment when actual well conditions can be fully assessed. Elements which can be considered at the time of well design and during drilling will, however, have an important bearing on the effectiveness of the subsequent suspension and/or abandonment.

The well-operator shall ensure that all materials used in the construction, and any subsequent modifications to the well, are suitable for its purpose. This is to ensure the well maintains its integrity for its entire lifecycle and risks to people from it are reduced to as low as is reasonably practicable.

The well-operator is required to report certain information regularly to HSE at such intervals as may be agreed between the operator and the authority or, failing agreement, at intervals of one week from operation commencement. The information to be provided includes start and end dates, the setting of casings and the depth achieved.

Co-operation is required between the well-operator, the installation operator/owner and other relevant contractors to ensure that their management systems and operating procedures are sufficiently integrated to provide a safe system of work.

The installation duty holder or well-operator (where the well is being worked on other than from an installation) must ensure that all staff are capable of carrying out the tasks that have been allocated to them by ensuring that they receive appropriate information, instruction, training and supervision.

Other health and safety legislation

The Provision and Use of Work Equipment Regulations 1998 (PUWER) cover workplaces where the HSW Act applies. PUWER also apply in common parts of shared buildings and temporary places of work. Generally, any equipment which is used by an employee at work, including any provided by the employee, is covered.

It must be ensured that equipment is suitable for use, and for the purpose and conditions in which it is to be used. The equipment must also be maintained in a safe condition for use so that people’s health and safety is not at risk.

Regulation 6 of the Management of Health and Safety at Work Regulations 1999, requires employers to provide employees with health surveillance. Employers must begin health surveillance on employees newly assigned to borehole operations prior to deploying them to that work.

If operators determine that personnel working at a borehole site may be exposed to atmospheres hazardous to their health then appropriate breathing and resuscitation equipment will be required to be provided and personnel trained in its use. The assessment and provision of equipment will enable the operator to comply with the Control of Substances Hazardous to Health Regulations 2002.

Other health and safety regulations apply to geothermal borehole sites, such as the Work at Height Regulations 2005, the Pressure Systems Safety Regulations 2000, the Personal Protective Equipment at Work Regulations 1992 and the Lifting Operations and Lifting Equipment Regulations 1998.