Why with natural gas what you can’t see can hurt you
08 March 2016
Natural gas is highly flammable so damaging a gas pipeline can cause major disruption, property damage, serious injury and even death. In 2015, there were approximately 500 incidents of actual damage caused to distribution gas pipes and several near misses at high pressure transmission pipelines.
More than 673,000 homes and businesses around Ireland use natural gas and benefit from the cost savings, convenience and reliability of the cleanest fossil fuel. Natural gas pipelines provide essential energy to hospitals, schools, homes and businesses 24 hours a day, every day of the year.
Gas Networks Ireland develops, operates and maintains Ireland’s 13,710 km natural gas pipeline network which operates at pressures from 20 mbar up to 85 bar. There are 2,422 km of high-pressure transmission steel pipelines which transport gas across the country at pressures up to 85 bar though mainly rural areas.
There are a further 11,288 km of distribution pipelines which operate at pressures up to 4 bar and are normally made from yellow polyethylene. These come in two forms: Mains and service pipes. Mains pipes carry gas under the roads and footpaths of towns and cities around the country. Services are connected to the mains pipes and supply gas to individual domestic and commercial premises.
The Gas Networks Ireland network is one of the safest networks in the world. A major risk to the network and to the safety of construction workers and the general public is the risk of damage caused by excavation works near gas pipelines. When excavating near gas pipelines, the following advice should be observed:
- Contact Gas Networks Ireland in plenty of time before work commences and obtain maps of the gas network (see below)
- Mechanical excavators should not be used within 500mm of distribution pipe or within three metres of a transmission pipe.
- Handheld power tools should not be used directly over a distribution pipeline (unless the gas pipe has been located by hand). Handheld power tools should not be used within 1.5 metres of a gas transmission pipeline.
The use of power tools presents a high risk to the operatives involved in the work.
- Hand digging using shovels and spades should be used where the presence of gas pipes is suspected or close to a known gas pipe.
Dial before you dig
To help reduce the instances of damage to the pipeline network, Gas Networks Ireland operates a ‘Dial Before You Dig’ service which provides information, safety advice and maps. This service is available to homeowners, small and large builders, planners and designers, engineers, landowners, farmers, utility owners, local authorities and any other party planning excavation works where there may be gas pipes present underground.
Underground gas pipelines can be damaged even during small jobs around the home, such as building extensions, new driveways, garden walls or landscaping. So no matter how big or small the job you are planning, designing or constructing, you should always check for the presence of underground gas pipes
Each year Gas Networks Ireland receives more than 4,000 inquiries regarding the underground natural gas pipeline network. In the interest of anyone undertaking the works and for the general public, it is essential that you have full site information on the location of gas pipelines before construction activities commence.
Remember that individual service pipes are not illustrated on the pipeline drawings. The drawing will show the mains gas pipes, which are yellow in colour and usually run parallel to the property in the road. The service pipe is connected to the mains and runs to the meter. It is generally positioned perpendicular to the mains pipe. If there is any doubt about the position of the pipeline, contact the Dial Before You Dig Service for further advice.
The Dial Before You Dig service is available by calling 1850 42 77 47, Monday to Friday 9am to 5pm. You can also email email@example.com to request information and maps.
The typical turnaround time for maps is within five days.
What to do if a gas pipe is damaged or if you smell gas in the area
Natural gas is lighter than air and will rise when released. It is non-toxic but can suffocate in enclosed or confined spaces. During an uncontrolled escape natural gas will rise, dilute and disperse into the air – assuming there is a clear path to the atmosphere. If the path to the atmosphere is blocked, however, the gas will travel through soil, ducts, drains, sewers and voids, and can follow the line of other buried utility services. This can lead to gas entering a building or other confined space and may lead to a fire or explosion
- Do not turn any electrical switches on or off, e.g. ignition switches.
- Do not operate any plant or equipment.
- Move people away from, any upwind of, the affected area. Restrict employee and public access to the affected area.
- Prevent smoking, the use of naked flames, the use of mobile phones and other ignition sources in the vicinity of the leak.
- Report the leak/damage immediately to the Gas Networks Ireland 24 Hour Emergency Service on 1850 20 50 50.
- Provide accurate information on your location and the nature of the incident.
- Do not attempt to repair the damage.
- Do not cover up a damaged main or service, this may lead to the gas travelling through soil, ducts, sewers, chambers or voids and potentially building up inside a premises or confined space.
- Do not turn off any gas valves in the road or footpath – you could cause further problems by doing so.
- Assist Gas Networks Ireland emergency personnel as required.
- Remember any damage to gas pipes, even if the pipe does not appear to be leaking, must be reported immediately to Gas Networks Ireland.
Gas Networks Ireland has prepared a simple guide, ‘Safety Advice for Working in the Vicinity of Natural Gas Pipes’, available at www.gasnetworks.ie/Dial which contains information on the risks associated with excavating near natural gas pipelines, the correct steps to take to stay safe and other useful information whenever you are excavating near gas pipelines.
The Health and Safety Authority has developed a Code of Practice for Avoiding Danger from Underground Services, which is available at www.hsa.ie