Frequently Asked Questions

Why is gas storage needed? Shouldn’t Northern Ireland be focusing on renewable energy sources?
Gas storage is needed because Northern Ireland presently generates 60% of its electricity from natural gas and has to import its entire gas requirement. The country’s location at the western limit of the European gas transmission network and its reliance on overseas gas markets makes it very vulnerable to the consequences of any disruption to gas supplies on a local and/or regional level. A gas storage facility in Northern Ireland will permit the more efficient use of its existing gas infrastructure and safeguard its ability to meet the increasing peak gas demand, whilst also providing a greater degree of security of supply.

Northern Ireland has a target to generate 40% of electricity from renewables by 2020 – this will primarily be achieved through wind-powered generation. A shift to renewable energy sources is likely to result in an increasing reliance on gas-fired power stations to support the fluctuations in supply from the intermittent nature of wind. Rapid cycle gas storage facilities, such as this planned project, will be important to respond to the rapidly fluctuating gas supply demands for electricity generation.

Why use salt for gas storage and why does it have to be in Islandmagee?
Deep underground storage is one of the safest and most environmentally-responsible methods of storing large quantities of natural gas. Pure salt, or halite, is an ideal medium for gas storage as it is impermeable to gas and can be easily dissolved in water to create a cavity deep underground.

The greatest limiting factor to the construction of a salt storage facility is the presence of a suitably thick geological salt layer at an appropriate depth below the surface. Such sites are rare in the British Isles and the area around Larne Lough is the only onshore site on the island of Ireland where salt deposits suited to gas storage use have been found.

Is underground gas storage safe?
Salt caverns have been used for storage of natural gas in Europe and the rest of the world for over 40 years and have proved to be a very safe and efficient means of storing gas. The potential hazards and risks associated with the storage of natural gas in salt caverns are well understood and effective safety standards have been developed to ensure that the risks from future developments can be managed successfully.

Can the brine not be re-used in some way rather than discharging it at sea?
The feasibility of re-using the brine was subjected to extensive study in the pre-planning stages of this project. Constructing a facility in Islandmagee capable of evaporating the water and recrystallising the brine would require a very substantial land area (more than 10 hectares, based on the size of similar salt recovery facilities in England). Constructing and operating such a facility would cause a greater environmental impact than the gas storage facility itself, particularly as it would only be in use for four years - the duration of the brine leaching operations.

Will discharging the brine into the sea harm the marine environment?
Protecting the marine environment in the sensitive waters around Islandmagee has always been one of our key concerns for this project, since our first scoping studies and initial seismic survey in Larne Lough in 2007. We fully understand the concerns about discharge of brine into the sea. However Permian age salt has been dissolved to create caverns and the resultant brine diffused and dispersed into seas and rivers in a number of locations across northern Europe, including in recent years off the Yorkshire coast, without any perceptible impact to the local environment or fishing industries. The selection of the outfall location for the Islandmagee Storage project was chosen after extensive work during the environmental impact assessment stage, which included detailed marine studies. The award of Planning permission does not cover the marine or operational elements of the project, which require separate consents from the Northern Ireland Environment Agency (NIEA) and others. The application process for the marine consents is beginning shortly. The discharge of brine will be closely monitored by the NIEA in real time to confirm that the salt is dispersing correctly and ensure there are no long-term impacts to marine life or fisheries as a result of the project.

What will the economic benefits of the project be and how might it benefit the local community?
The 500 million cubic metres gas storage facility will make a significant contribution to the security of gas supplies for the whole island of Ireland. The facility, when complete, will store enough gas to satisfy Northern Ireland’s demand for around 60 days.

The project will create more than 20 high quality permanent jobs, with construction activities generating temporary employment for over 200 people and providing widespread indirect economic benefits to the Islandmagee area.

Islandmagee Storage Limited is committed to supporting the local community and will be setting up a Trust which will support local projects and ideas themed around its main aims and objectives which will be Education, Geology and the Environment. It is proposed that there will be an initial investment of £1million on a range of projects in the first three years, following full funding of the gas storage project, with another £50,000 per annum thereafter for a minimum of 6 years. The Trust itself will also be able to apply for other sources of external funding to develop more projects and ideas.

I am worried about noise and traffic during the construction and operation of this project
Islandmagee Storage Limited have been working closely with the Environmental Health department of Larne Borough Council and DRD Roads Service to set out a programme of strict noise and traffic management measures to ensure that local residents experience the minimum possible disruption during the construction and subsequent operation of this facility. Prior to the commencement of the first phase of the project (the construction of the wellpad and drilling of the first well) we will be establishing a site office and local team on the ground whose first action will be to set up a system for local community liaison and who will be contactable at all times for queries or complaints during construction.

Who can I contact if I have any queries?
If you have any questions about the Islandmagee Storage Project which you feel haven’t been addressed within the project website,please click here.

Salt Core Well

How deep are you drilling?
The well is being drilled to a depth of approximately 1,700 metres. Drilling the well is necessary to obtain core samples of the Permian salt (approximately 200 metres thick). Once obtained, the samples will be analysed to confirm the depth, thickness and composition of the salt. This information will be used to complete the design of the caverns in which IMSL is proposing to store natural gas.

How long will the drilling activity last for?
All site operational activities associated with this work will be completed within a period of approximately 6 weeks.

Will the drilling be noisy?
The drilling activity will be carefully managed to ensure that noise does not affect nearby residents. Drilling will take place 24/7, but noise monitoring will take place throughout this period to ensure that noise thresholds set under local and national regulations and agreed with Environmental Health at Larne Borough Council are not exceeded and do not disturb sleep at the nearest properties.

The noise threshold not to be exceeded (set in the Planning Permission) at nearby properties is 45dB. In real terms this means noise levels equivalent to the following:

Quiet suburb, conversation at home. Large electrical transformers at 100 ft   50 dB   One-fourth as loud as 70 dB
Library, bird calls (44 dB); lowest limit of urban ambient sound   40 dB   One-eighth as loud as 70 dB

How much extra traffic will the drilling works generate and what is the route for this traffic?
There will be short periods lasting a few days at a time where there will be greater numbers of HGV vehicles than usual, for example where the component parts of the drilling rig are brought to the site for assembly and disassembled at the end. During these periods there will be around 20 HGVs per day. Outside of these short periods of increased activity, traffic is expected to be around 2-3 HGVs per day, plus up to 5 cars or minibuses for staff transport. The route to the site is via Browns Bay Road, Ferris Bay Road and Ballylumford Road, the same route used by HGVs accessing the Power Station. HGV traffic will not travel via the Hollow Road. Traffic management strategies agreed with Transport NI will be implemented to ensure that local traffic flows freely and safely. HGV movements will only be permitted during daytime hours.

How will the site be lit up during the night?
Drilling will be 24/7 therefore lighting will be required at the site for safety reasons and to minimise the impact on the local wildlife (i.e. preventing bird collisions and minimizing confusion for roosting bats). The location of the site and the location of the lighting units, to shine into rather than out of the site, will ensure that there will be no impact on local residents as a result.

What happens to the drilling and other waste?
All waste products generated on site including general site waste, drilling fluids/cuttings and accumulated rainwater will be held within secure containment areas inside the bunded wellpad; then removed offsite by licensed waste operators to appropriate licensed treatment and disposal facilities. Where possible waste materials (e.g. paper, plastic, glass, etc.) will be recycled. Drilling muds will be passed through a series of sealed tanks which removes the solids and permits the muds to be re-circulated down the well to reduce waste. Effluent from the site toilets and showers will also be held in tanks and transported offsite by tanker for treatment and disposal at an appropriate waste water treatment facility.

Does the exploration activity pose a risk to human health?
No. The only potential risks to human health relate to the general health and safety hazards presented by any construction site, which are only applicable to the personnel working on the site.

The operation of the salt core well comes under the Borehole Sites and Operations (NI) Regulations 1995, and Offshore Installations and Wells (Design and Construction) Regulations (NI) 1996 and IMSL representatives have responsibility for their health and safety requirements.

There is no risk to human health posed on persons not directly involved in drilling activities. As with most construction sites the immediate site area will not be accessible for safety and security reasons. Therefore there should be no reason for non-authorised personnel to be on the site.

What happens after the drilling, is this the start of the actual gas storage project construction?
No. The only potential risks to human health relate to the general health and safety hazards presented by any construction site, which are only applicable to the personnel working on the site.

No. The salt cores will be sent to a laboratory and various tests will be conducted to enable the engineers to determine the engineering parameters for the operation of the caverns subsequently created within the salt interval. Tests on the salt cores will also confirm the composition of the salt, important data for regulating and monitoring of the brine discharge into the sea during cavern construction under the marine discharge licence. All the data will enable the project to reach the point where a decision can be made on full construction during the first half of 2016. The earliest start date for the project construction would be towards the end of 2016, with the first caverns becoming operational in 2019.