Reducing third party damage to onshore pipelines
Third party damage, as the term is used in this article, refers to any accidental damage done to the pipe as a result of activities of personnel not associated with the pipeline. This failure mode is sometimes called outside force or external force. Pipeline integrity is an important requirement for the safe and reliable operation of a gas transmission system. Major threats to pipeline integrity includes third party damage, corrosion, cracking, stress, material and construction defects, soil movements and other problems. Of these, third-party damage leading to leaks and ruptures in line pipe is a major threat for buried gas transmission pipeline system.
The main source of leaks occurring from high-pressure gas transmission pipelines in both the United Kingdom and Europe is due to the damage caused by third party activity. Therefore, where there is high possibility of third party activity along the pipeline right-of-way (ROW), a higher degree of inbuilt safety against such third party activity should be specified. 
As shown in Figure 4.1, third-party damage may be caused by the following activities on or near the pipeline Right-Of-Way:
Operating vehicles or mobile equipment over the right-of-way where a roadway does not exist;
Reducing the depth of soil covering the pipeline;
Ploughing deeper than 30 cm (1 foot);
Installing drainage systems;
Ditch digging/clearing/ excavation
Third-party damage to pipelines can
cause penetration of the pipe wall;
dents, gouges, cracks;
rupture the pipeline; or
reduce the pressure strength of the pipeline below the maximum allowable operating pressure
This paper proposes solutions to help pipeline owners and operators to end third party damage to their pipeline.
If through risk assessments or by direct examination you determine the pipeline is vulnerable to third party damage, one or more of the following remedial/mitigation measures should be introduced before or throughout construction and for the duration of pipeline operation. 
Burial depth (increase the depth of burial)
Provide additional protection
Right – of- way intrusion detection
Improved material quality
Design factor: use of lower design factor
The above mentioned mitigation measures are as described below.
2.1 Public awareness
Before the commencement of pipeline construction, at least 85% of landowners along the pipeline route should have indicated their willingness to have the pipeline within their land (i.e. approval in principle). However, approval in principle has no bases in law and does not contain any rights to construct the pipeline.
It is a good practice to consult with local authorities, statutory bodies and non-statutory groups before the construction of pipeline. It is also necessary to obtain approval in principle from various service industries, whose lines the pipeline crosses.
Once discussions begin with various landowners and third parties, concern will be expressed by various organisations and pressure groups along the proposed route of the pipeline. In order to lessen the problems, it is generally good practice if these groups are contacted and given the opportunity to comment on the proposed project at an early stage. The design engineer or consultant is to help with the following public education activities (refer to Table 2-1 of API RP 1162).
Produce handouts and brochures eg. safety brochures
Attend exhibitions and presentations
Issue environmental leaflets and information
Liaison with local authorities
Liaison with landowner/occupiers
Answer general enquiries from the public
If powers are available for the pipeline owner to buy land or acquire rights over the land in which to place a pipeline without the agreement of the landowner or occupier, this should be investigated and used where necessary.
Public Awareness programs can be conducted monthly to create an awareness among the people. API RP 1162, 49 CFR 195.440, and 49 CFR 192.616 standard provides guidance for the development and implementation of enhanced public awareness programs.
2.2 Route selection
Successful pipeline routing is the key to providing a pipeline system that optimizes material cost, construction and safety. Pipeline routing is inevitably a compromise between opposing factors of minimum route length, avoidance of populated areas, wet or rocky ground or mountainous regions, reduction in major crossings, statutory requirements and obtaining permission of landowners.
For new pipelines, take into consideration potential for population density increase and thereby avoiding such future problems areas. Route pipelines away from densely populated areas (eg. towns, cities, villages,) by a sufficient margin to avoid any impact in the future for expansion.
General requirements and identification of parameters to consider when routing pipelines onshore are considered here. These parameters are numerous and each pipeline has to be assessed individually. It is difficult to provide examples due to the different parameters to be used and the relative weight given to each of them. The parameters include;
Landownership and compensation
Land use and type
Safety codes and requirements
Existing Pipelines, utilities and overhead power cables
Pipeline routing onshore is the key activity, incorporating a multitude of different factors to be considered and a compromise chosen between some, whilst compliance with others is a statutory requirement.
2.3 Burial depth : increased depth of burial
Onshore pipelines are normally buried, for the following reasons:
Protection against damage,
Reduced environmental and aesthetic impact,
To reduce the area of land ‘sterilized’ by the pipeline (in terms of limits on land use for buildings etc).
The depth to which a pipeline is buried depends on a number of different factors. The minimum cover from the top of a pipeline to the surface is normally referenced in the design codes at 0.9m as shown below in Table 2.1. This allows enough cover for most agricultural activities to take place above the buried pipeline without interference and for most other utilities to be laid above the pipeline if required. This cover is normally reduced in areas of rock due to the difficulty in digging the trench and the lack of activity in the ground above the pipeline. Recently, in most pipeline project, a minimum cover requirement of 1.1 m has been set.
In built up areas (towns, cities) and close to areas of activity (main roads etc), historical evidence has shown that increased cover over the pipeline up to a maximum of 2 metres gives significant benefits in reducing the number of impacts from third parties, most of which limit their actions to within 1 to 1.5 metres depth. The likelihood of damage has been shown to reduce by a factor of 10 by increasing the cover from 1.2m to 2.2 m in an evaluation of damage data from most gas transmission system.
Although the effect of increased cover has the effect of increasing cost as the trench and amount of earth to be moved increases proportionally with depth, increase the depth to which the pipeline is buried. For a 36” pipeline, the trench could increase up to 3.5 m below ground level if cover of 2.2 m was thought necessary in certain areas. This in itself poses additional dangers to the construction personnel in terms of trench collapse and additional problems in terms of water collection within the trench. 
Figure 2.1 A natural gas pipeline being buried
Table 2.1 Minimum cover for buried pipelines [1, 7-8]
2.4 Provide additional protection
Generally, provide additional protection to the pipeline by increased wall thickness, concrete slabs, tiles, plates (eg. Overpipe High Density Polyethylene plate), high tensile netting, sleeving, etc. in areas considered to have increased potential for third party activity and potential harm to the human population from damage to a high-pressure gas pipeline.
Reinforced concrete slabs, tiles or steel plates are buried above the pipeline so that in the event of excavation the slab, tile or plate is encountered before the pipeline. In theory, damage is limited to the slab, tile or plate and not the pipeline. 
Figure 2.2 Overpipe HDPE
2.5 Pipeline Surveillance
Routine surveillance of the complete pipeline should be undertaken throughout its operational life. Primarily, this is to ensure the continued integrity of the pipeline by the early detection of any third party activities on, or in the vicinity of, the route. Such surveillance should also identify any loss of cover or subsidence.
Surveillance should be undertaken by a combination of both line walking and helicopter patrols, the frequency of such inspections will be subject to discussion and agreement with the operator and the energy ministry.
1. Increase the frequency of pipeline Right-of-way (ROW) inspection eg. Helicopter surveillance, Aerial/vehicle/foot patrols, satellite surveillance, vantage point survey etc.
Line walking: At regular intervals, a representative of the operator should inspect the complete length of the pipeline on foot. To assist in this inspection, the pipelines should be delineated by pipeline marker posts.
Helicopter patrols: At regular intervals, a helicopter inspection of the entire pipeline route should be undertaken and video records made. To assist the helicopter patrol to locate the pipeline, ‘aerial marker post’ should be positioned at strategic locations. To enable these markers to be easily visible to the helicopter crew, they should be designed with a reflective coloured (day glow) surface.
Patrol problem areas within every three days and one week for other areas.
Ensure unapproved accesses are not used to cross the ROW.
Prevent unauthorized activities on the ROW
2. Enhance ROW visibility through clearing. Clearing of vegetation covering ROW markers and signs. Weed around the markers 1-meter radius by chemical or manual methods (see Figure 2.3).
Tree roots are attracted to the loosened soil of the pipeline ditch and to the typically constant temperature created by the moving gas. Tree roots can damage the coating and come in contact with the pipe steel. Tree roots carry water and nutrients to the rest of the tree and for that reason are very good conductors of electricity. Risks associated with corrosion leaks and corrosion-related pipeline failures are significantly increased when the pipeline coating is damaged and the tree roots absorb the electric current necessary to stop corrosion.
Trees often hide pipeline markers and the corridor that reminds neighbors and contractors of a pipeline in the area. Keeping the pipeline right-of-way clear reduces the risks of third party damage and increases the safety of all. 
No one wants to lose a tree after many years of growth. Pipelines need maintenance and may even need to be replaced. Trees growing in the pipeline right-of-way could be destroyed when these activities are required.
Third parties should not plant closer than 25 feet from any natural gas transmission line.
3. Liaison and better conversation with landowners to identify pipeline locations and to handle land usage issues
Figure 2.3 Clearing of vegetation covering ROW markers and signs
2.6 Improve signage
Improve signage on onshore pipelines by marking pipeline with marker post, pipeline markers (which includes information of type of fluid, pressure etc.), road crossing markers, river bottom protections, rail crossing markers, river crossing markers etc. These interventions are meant to exclude unauthorized activities from the pipeline Right of Way (ROW) and are thus, monitored regularly.
Pipeline markers as shown in Figure 2.4-2.5, should be installed at field and property boundaries and at both sides of road, rail and major water crossings. Markers and cathodic protection (CP) test post for the facilities should be placed in such a way as not to be obscured by vegetation and allow normal access for hedge or grass cutting operations. The pipeline markers should indicate the pipeline owner, telephone number in case of emergency, the product being transported, pipe size, direction of flow and the distance in kilometers from the control station.
Marker post containing CP test facilities can be installed at 1km intervals. At yearly intervals, the pipeline operator should carry out routine maintenance of these markers. All paint used during this regular maintenance and any other painted surfaces, eg. Fencing, etc. should be a type that is not harmful to livestock.
Figure 2.4 A marker post for a buried gas pipeline
Figure 2.5 Cathodic protection test post
2.7 Right – of- way intrusion detection
The effect of third party interference to onshore pipelines includes pipe service disruptions, property destruction, environmental damage, economic loss and even death. Whether it is malicious sabotage, or an incidental construction mistake, detecting a third party interference when it happens and precisely locating where it is occurring along the length of a pipeline are vital to mitigating potentially catastrophic situation.
Therefore, install intrusion detection system using fibre optic stress sensors to prevent right-of-way, third party external interference. The intrusion detection system is normally used for above ground piping system to prevent people from damaging the pipeline.
For example, In the case of the Asian gas supplier, Guangdong Natural Gas Group (GDNGG), fiber optic sensing has proved to be a highly accurate, reliable and cost-effective tool, which can not only detect leaks with precise location identification, but also, when paired with Maxview Integration Software, alarms personnel to events occurring around the pipeline – proactively preventing damage.
Also a Threatscan system when installed on a pipeline will enable the operator to identify location of plant and equipment working in close proximity to the pipeline without physical impact damage taking place. This will allow the operator to take proactive precautionary measures to safeguard the system integrity before damage occurs.
2.8 Notification system
Introduction of third party enquiry system, i.e. ‘call before you dig’ or ‘one call system’. An operator of a pipeline should establish a written programme to prevent damage to that pipeline from excavation activities. The term “excavation activities” includes excavation, blasting, boring, tunnelling, backfilling, the removal of above ground structures by either explosive or mechanical means, and other earth moving operations.
Provide support to organisations or individuals carrying out works close to pipelines eg. Excavator drivers, road construction crew, farmers, homeowners, tenants, one-call partners, residential or commercial activities, etc. 
In areas that are covered by more than one qualified one-call system, an operator need only join one of the qualified one-call systems if there is a central telephone number for excavators to call for excavation activities, or if the one-call systems in those areas communicate with one another.
The safety of pipelines on land, especially those containing flammable liquids or gas and poisonous chemicals, is paramount. Regulations exist in most countries which specify what precautions are to be undertaken or what safety studies or risk analyses must be undertaken to demonstrate the effectiveness of the various safety measures employed. The design codes provide guidance on what safety measures are recommended and other safety related items such as minimum distances from buildings etc., especially for gas pipelines.
The design codes both make mention of certain variances being possible provided that a safety authority can be satisfied by a safety analysis that the variance is acceptable in terms of Health and Safety to the general public. The Safety Authority may require a safety analysis as standard to demonstrate the level of risk arising from the construction of a gas pipeline. Particular additional requirements and regulations are dependent on the individual country and can be onerous in terms of items such as maximum pressure, number of block valve stations and application of design codes.
As an example, minimum proximity distances of the pipeline from certain dwellings are required by certain design codes, in particular BS 8010, as a recognition of the potential effect of a gas pipeline rupture for whatever reason. The minimum proximity distances rise according to maximum operating pressure (MOP), pipeline size and wall thickness. For a large diameter high pressure gas pipeline this can be a considerable distance. Using BS 8010, a 36” gas pipeline at 100 barg MOP and using a design factor of 0.72 has to be separated by 100 m from any dwelling or parallel to any main roads and for a 40“150 barg gas pipeline this rises to 150 m.
A comprehensive safety analysis / risk analysis is recommended for gas pipelines that run through or close to populated areas.
Annual risk assessment of all the threats by multi-disciplinary team
Emergency response and control planning reviewed based on risk assessment
Strengthening administrative controls for condition monitoring
Focused efforts on surveillance across pipeline
To manage risk where location class has changed since commissioning?
De-rate the pipe section to Maximum Allowable Operating Pressure (MAOP) applicable to that class location
Strengthen the pipe i.e. increase MAOP to original value
Increase the existing pipe wall thickness
Cut and replace with higher thickness/ higher SMYS pipe
Re-test the pipe section to establish higher MAOP
Based on risk assessment, take suitable measures to mitigate risks to acceptable limits. Use integrity assessment methods prescribed by codes, develop & follow performance plan for risk mitigation
2.10 Design factor
Design factors are the factors given in the design codes which limit the fraction of specified minimum yield strength (SMYS) of the pipe material which the pipe will be subject to when the pipe is internally pressurized, is restrained during expansion or contraction, has external forces and torque applied to it or any combination of the above.Design factors have been used since pipeline design codes were first established, to provide a defined level of safety and mechanical strength.
Design factor is an important concept in all pipeline codes. Design factor is the ratio between the operating (hoop) stress in the pipeline and its yield stress. Apart from exceptional circumstances, the wall thickness of onshore pipelines is determined by the hoop stress and the choice of design factor, which limits the stress in the pipe to a defined fraction of the specified minimum yield stress (SMYS) of the pipe material. The choice of design factor is limited by the design codes to a maximum of 0.8 or 0.72 and a minimum of 0.4 or 0.3. The lower design factors stated in the codes can be increased in most instances provided additional measures are taken or a risk & safety analysis shows that the potential risk is still acceptable when using a higher design factor.
Third party activity has always been, and remains to this day, the primary cause of major failures in pipelines. It therefore follows that where an increased possibility of third party activity is found, a larger degree of inbuilt safety against such activity is indicated. A reduction in design factor / use of lower design factor provides this and is recognized in the codes. 
Table 2.2 General design factors
The use of a 0.8 design factor in ASME B31.8 is subject to a hydrotest of 1.25 times the design pressure if the MOP is above 72% of the SMYS. Other location classes allow use of air or gas tests instead of water.
3. CASE STUDY: GHISLENGHIEN GAS PIPELINE EXPLOSION
On July 30 2004, a high-pressure natural gas pipeline operated at a pressure of 70 bar ruptured following recent third party damage. Twenty-four people died as a result and 150 survivors were hospitalized, most with severe burns.
It is thought that damage to the pipeline occurred during the final stages of a car park construction project. Notice of the work had been given to the pipeline operator, Fluxys, and one of their operatives had regularly attended the site through the course of the project. Damage to the pipeline probably occurred as a mechanical soil stabilizer was driven over it or nearby. This resulted in several evenly spaced (but not full depth) gouges in the steel wall of the pipeline. Two weeks after the completion of the car park gas pressure was increased in the pipeline, which then ruptured with the fault centered on a 350 mm long gouge. Other contributing factors to the accident may have been a reduced cover over the pipeline as a result of leveling, the way information was passed down the sub-contracting chain to workers and the frequency and adequacy of supervision by the pipeline operator at the site.
Ghislenghien disaster is a typical of third party damage incidents, which are often a result of roadside utilities work.
Figure 3.1 Ghislenghien gas pipeline explosion 
3.1 What caused the accident
Operating a mechanical soil stabilizer over the pipeline right-of-way or nearby. This resulted in several evenly spaced (but not full depth) gouges in the steel wall of the pipeline.
Reducing the depth of soil covering the pipeline as a result of leveling,
Communication and supervision: the way information was passed down the sub-contracting chain to workers and the frequency and adequacy of supervision by the pipeline operator at the site.
3.2 How do we avoid such incidents?
a) Burial depth
As discussed above in section 2.3 and Table 2.1, in built up areas (towns, cities) and close to areas of activity (main roads etc.), historical evidence has shown that increased cover over the pipeline up to a maximum of 2 meters gives significant benefits in reducing the number of impacts from third parties, most of which limit their actions to within 1 to 1.5 meters’ depth. The likelihood of damage has been shown to reduce by a factor of 10 by increasing the cover from 1.1m to 2.2 m in an evaluation of damage data from most gas transmission system. Therefore, increase the depth to which the pipeline is buried.
b) Provide additional protection
The leak occurred as consequence of “external aggression”, i.e. the scratching of the pipe wall by a mechanical excavator or mechanical soil stabilizer, with a wall thickness of 4 mm instead of the nominal 10mm. As discussed in section 2.4 above, Concrete slab is suggested for vehicular movement above the pipeline. Provide additional protection to the pipeline by increased wall thickness, concrete slabs/tiles/plates (eg. Overpipe HDPE plate), high tensile netting, sleeving, etc. in areas considered to have increased potential for third party activity and potential harm to the human population from damage to a high-pressure gas pipeline
An operator of a pipeline should establish a written programme to prevent damage to that pipeline from excavation activities. Critical actions to be undertaken during excavation activities includes
A system to receive and record notification of planned excavation activity
Dispatching of personnel to the site to provide detailed markers of pipeline location
Comprehensive marking and locating procedures and training
Accurate maps and records showing pipeline locations, depths, and specifications
Prejob communications or meetings with the excavators
On-site inspection during the excavation
A system to ensure updating of drawings
Inspection of the pipeline facilities after the excavation. The evaluator may look for documentation or other evidence to satisfy himself that an appropriate number of these often critical actions is being taken
Engineers should only agree with the construction work (digging task) in pipeline zone if the construction work has fulfilled the requirements of the engineering design and specifications. The engineers should not allow the use of mechanical diggers or potential mechanical aggression that might cause the leak of pipeline and consequently threaten the life of most people.
Only experienced and trained engineers should be allowed to supervise such construction activities.
Increase patrolling, when construction is in progress and area included in vulnerable location.
Barricading of ROW when construction work is in progress
Concrete slab is suggested for vehicular movement above the pipeline.
Install additional warning markers at every 10 m
Install leak detectors along the pipeline and shutdown pipeline in case of leakage. Flow variations/SCADA can even be used to detect leakage in the pipeline system.
Perform Safety analysis/risk analysis before any construction work near the pipeline right of way. Based on risk assessment, take suitable measures to mitigate risks to acceptable limits. Use integrity assessment methods prescribed by codes, develop and follow performance plan for risk mitigation
Contractor should obey and adhere to safety standard and regulations
Cut and replace the damaged pipe section
4. CASE STUDY: ANOTHER SABOTAGE? GAS PIPELINES AT TEMA TORCHED BY SUSPECTED ARSONISTS
On April 9 2019, some security men doing some regular checks along the pipelines that take one of the generating plants within the Tema enclave discovered that some persons had packed car tyres over some pipelines that were transmitting fuel to the generation plant and had torched these tyres, so the pipelines were burning (see Figure 4.1).
Figure 4.1 Gas pipelines at Tema torched by suspected arsonists 
4.1 How do we avoid such incidents?
Above-ground pipelines and components have different type of third party damage exposure compared to buried sections. Included in this type of exposure are the threats of vehicular collision and vandalism. The argument can be made that these threats are partially offset by the benefit of having the facility in plain sight, thereby avoiding damages caused by not knowing exactly where the pipeline is (as is the case for buried sections). Pipelines and equipment located above-ground has a risk of failure approximately 100 times greater than for facilities underground.
Sabotage is intentional acts designed to upset pipeline operation. Sabotage, vandalism, and other wanton acts of mischief is primarily considered to be a direct attack against the pipeline owner. Because of the strategic value of pipelines and their vulnerable locations, pipelines are also attacked for other reasons. Secondary motivations may include pipeline sabotage as
An indirect attack against government that supports the pipeline
A means of drawing attention to unrelated cause
A protest for political, social or environmental reasons
A way to demoralize the public by undermining public confidence in its government’s ability to provide basic services and security.
Conditions that reduce the risk of third-party damage to above-ground components will often take the form of vehicle barriers or other obstacles or discouragements to intrusion. Credit should be given for security measures that are thought to reduce vandalism (intentional third-party intrusions). In addition, to that which have been discussed above in chapter 2, the following may be used as risk reducers when considering mitigation of third-party damage to above-ground pipelines and components. 
1). Barrier –type prevention
Electrified fence in proper working condition
Strong fence/gate designed to prevent unauthorized entry by humans (eg. Barbed wire, anti-scaling attachments, heavy-gauge wire, thick wood, or other anti-penetration barrier)
Normal fencing (chain link etc.)
String locks not easily defeated
Guards (professional, competent) or guard dogs (trained)
Alarms: deterrent type designed to drive away intruders with lights, sounds, etc.
Barriers to prevent forcible entry by vehicles (these may be appropriate in extreme cases. Ditches and other terrain obstacles provide a measure of protection. Barricades that do not allow a direct route into the facility, but instead force a slow, twisting manoeuvre around the barricades, prevent rapid penetration by a vehicle.)
Dense thorny vegetation (this type of vegetation provides a barrier to unauthorized entry. On the other hand, it also provides cover for a perpetrator.
High visibility (difficult to approach the site undetected)
2). Detection – type prevention
Staffing: give maximum value for full-time staffing with multiple personnel at all times.
Video surveillance: real-time monitoring and response, video surveillance for recording purpose only.
Alarms, with timely response: sound monitors, motion sensors, alarm systems, etc.,
Supervisory Control and Data Acquisition (SCADA) system: such a system can provide an indication of tampering with equipment because the signal to the control room should change as a transmitter or meter changes.
Satellite surveillance: with increasingly better resolution, such option is viable today for observing a pipeline and the surrounding area continuously or at any appropriate interval.
Explosive dye markers: these devices that spray a dye on a perpetrator to facilitate apprehension and prosecution.
Intrusion detection system
All detection-type prevention must be coupled with timely response.
3). Patrolling as discussed in section 2.5 above. Varying the patrol and inspection schedules enhances this as a sabotage preventive measure.
4). Any of the above measures can also be simulated rather than real. Examples of simulated measures include plastic that appears to be steel bars, fake cameras, and signs of warning measures that do not exist. Whilst obviously not as effective as the genuine deterrents, these are still somewhat effective.
4.1.1 Internal sabotage
An employee with the intent to do harm is usually in a better position to cause damage due to his likely superior knowledge of the process, equipment, and security obstacles, as well as his unquestioned access to sensitive areas. Some preventive measures are available to the operating company. Common deterrents include
Thorough screening of new employees
Limiting access to the most sensitive areas
Training of all employees to be alert to suspicious activities
4.2 How do we fix the damaged pipe?
1. Cut and replace
The most cost-effective and/or safest way to repair the pipeline defect is to remove the affected segment of pipe (cut the defect) and replace with a pre-tested section of sound pipe, tie-in welds should be inspected and returned to service. If the pipe is not pre-tested, then it has to be hydro-tested before the pipeline is returned to normal service. Removal and testing of the pipe section will necessitate shutdown and depressurization of the pipeline.
The above mentioned mitigation measures provides substantial information than has previously existed for decision makers regarding oil and gas pipeline damage originating from third party activity.
IGEM. IGEM/TD/1 Edition 5 - Steel pipelines for high pressure gas transmission. 5ed. London: IGEM; 2008.
John Mather, Chris Blackmore, Andrew Petrie & Charlotte Treves. An assessment of measures in use for gas pipelines to mitigate against damage caused by third party activity [Internet]. Warrington: WS Atkins Consultants Ltd; 2001. Available from: http://www.hse.gov.uk/research/crr_pdf/2001/crr01372.pdf
Lidiak, P. Hazardous Liquids Pipeline Industry Perspective on Excavation Damage. New Orleans: Pipeline Safety Trust Conference; 2010. 4 p
Muhlbauer W. K. Pipeline risk management manual: ideas, techniques, and resources. Third ed. USA: Gulf professional publishing; 2004. 3-50 p.
North Western Energy. Planting trees near gas pipelines [Internet]. Montana: NWE; 2016. Available from: https://www.northwesternenergy.com/safety/community-safety/planting-trees-near-gas-pipelines
Peace FM. Another Sabotage? Gas Pipelines at Tema Torched by Suspected Arsonists [Internet]. Accra: Peace FM; 2019. Available from: http://www.peacefmonline.com/pages/local/news/201904/379704.php
ASME. Gas Transmission and Distribution Piping Systems – B31.8. USA: ASME; 2010. 136.
Ghana Standards Authority. Natural gas pipeline safety (construction, operation and maintenance) regulations – L. I. 2189. Ghana: GSA; 2012. 85p.
Organization for Economic Co-Operation and Development (OECD). Report of the OECD Workshop on Pipelines (Prevention of, Preparedness for, and Response to Releases of Hazardous Substances) [Internet]. Paris: OECD; 1997. 17-18p. Available from: http://www.oecd.org/officialdocuments/publicdisplaydocumentpdf/?doclanguage=en&cote=ocde/gd(97)180