Toronto Fire Services - Natural Gas/Methane Incidents PDF

STANDARD OPERATING GUIDELINE NATURAL GAS/METHANE INCIDENTS Date Issued: March 29, 2019 Rescinds: December 1, 2008 Section: Incident and Emergency Operations File Code: G-NATU PURPOSE To provide all Toronto Fire Services personnel with a guideline for responding to and safely mitigating natural gas/...

STANDARD OPERATING GUIDELINE NATURAL GAS/METHANE INCIDENTS Date Issued: March 29, 2019 Rescinds: December 1, 2008 Section: Incident and Emergency Operations File Code: G-NATU PURPOSE To provide all Toronto Fire Services personnel with a guideline for responding to and safely mitigating natural gas/methane emergency incidents. RESPONSIBILITY All TFS personnel are responsible for following proper guidelines at a natural gas/methane incident to ensure the health, safety and welfare of themselves and all others. The Incident Commander is responsible for following proper guidelines at a natural gas/methane incident to ensure the health, safety and welfare of themselves and all others, making all necessary notifications and completing/forwarding all documentation and reports. The Communications Centre Officer is responsible for ensuring assistance is provided to the Incident Commander with notification of necessary agencies and companies required on scene. GUIDELINES 1. Mandatory Use of Full Personal Protective Equipment and SCBA 1.1. Full Personal Protective Equipment (PPE) and Self-Contained Breathing Apparatus (SCBA) shall be donned and activated before entering or operating in any confirmed or suspected natural gas/methane atmosphere where air monitoring equipment oxygen (O2) readings are 20% or less or when observations and information received on arrival indicates the presence of high levels of natural gas/methane. 2. First Arrive Apparatus 2.1. The expected first arriving apparatus shall confirm wind direction and speed while en route to the incident to ensure an upwind approach to the scene. 2.2. All incoming apparatus other than the first arriving apparatus should remain based at their apparatus (a safe distance away) unless called to the incident by the Incident Commander. 2.3. The Incident Commander shall ensure that a 65 mm hose line is deployed and charged once personnel are brought forward. 2.4. Natural gas lines can be classified into categories as follows: File Code: G-NATU Page 1 of 6  STANDARD OPERATING GUIDELINE Line Type Pressure Transmission (up to 122 cm/leaking sounds like a jet engine) 6 205 - 9 929 kPa Distribution 1 207 - 3 448 kPa Service (Industrial) Up to 450 kPa Services (Commercial/Institutional) 1.7 - 140 kP Service (Residential) 1.7 kPa 2.5. Natural gas within most transmission lines is not odourized 1 3. No Entry Natural Gas Level for TFS Personnel 3.1. TFS personnel shall not enter any area when an air monitoring instrument indicates explosive/combustible vapours present at 50% of the LEL (lower explosive limit) or more. 4. Rescue and Evacuation of Persons 4.1. The Incident Commander shall direct personnel to immediately rescue, decontaminate (for liquid) and treat all effected or injured persons while requesting Toronto EMS (if not already on scene). 4.2. Complicated rescue/recovery of persons trapped inside of maintenance holes, sewers, vaults, excavations, etc., shall only be performed by qualified TFS Confined Space Rescue Technicians utilizing approved air monitoring and confined space rescue equipment and procedures. 4.3. Personnel shall immediately evacuate the building of all persons and the outdoor area of all civilians and unnecessary emergency response personnel and apparatus for 50 m - 100 m in all directions. For large natural gas/methane leaks or fires, distances up to 800 m downwind should be considered. 4.4. The evacuation area shall be secured with barrier tape, etc., to prevent unauthorized entry. 4.5. Toronto Police Services personnel should be requested to restrict or re-route all traffic (vehicle and/or pedestrian, etc.) away from the evacuation area. 5. Notification of Enbridge Gas Distribution 5.1. The Incident Commander shall ensure the TFS Communication Centre notifies Enbridge Gas Distribution immediately upon first indication that natural gas is involved in all incidents except natural gas vehicles. 5.2. Enbridge Gas Distribution representatives should be directed to report to the Incident Commander upon their arrival. Enbridge Gas Distribution would appreciate the opportunity to exchange information with TFS officials at the scene. 5.3. Personnel should report any observations of damage and/or temporary repair by workers or civilians to the Enbridge Gas Distribution representative immediately upon their arrival. 1 Ontario Natural Gas Association, Natural Gas Awareness for Firefighters (Emergencies Involving Natural Gas, 5-3) January 1999. File Code: G-NATU Page 2 of 6  STANDARD OPERATING GUIDELINE 5.4. Enquiries from the media about the natural gas emergency should be directed to the Enbridge Gas Distribution officials. In many instances there are technicalities involved that require clarification. As a matter of policy, Enbridge Gas Distribution attempts to supply the news media with all the facts to prevent distortions, exaggerations and misinterpretations of facts. 5.5. For details surrounding notification of Enbridge Gas Distribution refer to Standard Operating Guideline G-OAEN — Other Agencies (Non-Emergency) – Ministry of Environment (MOE). 6. Prevention of Natural Gas Fires/Explosions (Indoor and/or Outdoor) 6.1. Personnel shall control all sources of potential ignition of escaping natural gas by doing the following: a) Shutting off all open flame appliances by closing fuel supply valves. b) Not operating electrical switch (on/open or off/closed) equipment. c) Do not create static electricity sparks in the building. d) Extinguishing all open flames and pilot lights. e) Prohibiting smoking in the area. f) Placing all fire apparatus upwind. g) Shutting vehicle engines off if able to do so. h) Not allowing operation of any electrical or fuel operated equipment in the area. 6.2. Personnel should ensure safe dispersion of the natural gas vapours by natural ventilation, fog streams or intrinsically safe mechanical ventilation starting, if possible, where the natural gas concentration is the highest. 6.3. Close all windows and doors of neighbouring buildings to prevent natural gas from entering. 6.4. Check all interior levels of neighbouring buildings including basements and outside areas such as sewers for the presence of natural gas/methane by using explosive/combustible gas monitoring instruments. 7. Control of Natural Gas Fires (Indoor and/or Outdoor) 7.1. TFS personnel shall not extinguish a natural gas fire unless the natural gas flow or leak can be stopped by closing natural gas supply valves before or immediately after extinguishment of the fire. Fire consuming escaping natural gas and extinguishment of the flame results in the spread of natural gas to other areas with the hazardous potential of explosion or rapid fire. 7.2. The stopping of the natural gas flow to an entire building can be attempted by closing the natural gas meter supply valve. 7.3. Readily accessible natural gas supply valves may be closed by TFS personnel to stop the flow of natural gas when safe to do so. 7.4. Consideration for turning off the natural gas flow to commercial or industrial buildings should be taken as this action may seriously interrupt important File Code: G-NATU Page 3 of 6  STANDARD OPERATING GUIDELINE production processes and possibly create further hazards such as cutting off the natural gas supply to stand-by emergency electrical generators. 7.5. Underground natural gas supply valves to buildings may be only accessible to Enbridge Gas Distribution representatives. 7.6. If the fire is isolated to a single appliance, personnel should shut off the natural gas flow at the appliance supply valve. 7.7. Personnel should spray water fog on any surrounding combustibles and/or exposures if in danger of igniting before natural gas flow can be stopped. 7.8. Do not assume that all escaping natural gas is being consumed by the fire. Check for natural gas accumulations in nearby buildings, sewers, etc., utilizing natural gas monitoring instruments. 7.9. For non-natural gas fires in buildings, if it appears that natural gas piping or the meter installation is going to be endangered, the Incident Commander shall ensure the natural gas supply is shut off as soon as possible. 8. Natural Gas/Methane in Maintenance Holes, Sewers, Vaults, Excavations, etc. 8.1. TFS personnel shall not enter a confined space, maintenance hole, sewer, vault or excavation if natural gas/methane is suspected to be present. 8.2. The Incident Commander shall ensure personnel do not use water in an excavation hole as mud and water fill the hole and weaken the sites integrity making the entry for repair more hazardous for utility personnel. 9. Damaged Natural Gas Pipelines, Meters and Pressure Regulators 9.1. Stopping the flow of broken natural gas pipes, meters or pressure regulators shall not be attempted by TFS personnel. TFS personnel may assist trained and equipped Enbridge Gas Distribution personnel. 9.2. The hazards associated with plugging/capping metal pipe and crimping/clamping of plastic pipe can only be eliminated by trained and equipped Enbridge Gas Distribution personnel. 9.3. TFS attempts to control the escaping natural gas from damaged pipes shall be limited to turning off the natural gas at supply valves only. 9.4. TFS personnel shall not operate any underground or aboveground regulator station or commercial or industrial service line valve. 9.5. Natural gas valves installed on system mains, stations and commercial / industrial service lines shall not be operated by persons other than trained Enbridge Gas Distribution personnel. 9.6. Natural gas system main, station and commercial/industrial valves are installed at locations in accordance with the following: a) Distribution Mains (below ground). File Code: G-NATU Page 4 of 6  STANDARD OPERATING GUIDELINE b) Regulator Stations (above ground). c) Commercial/industrial service lines (above and below ground). 9.7. Residential service line shut-off valves (above ground) may be closed by TFS personnel if there is immediate risk of personal/public safety or property damage. 9.8. If there is no immediate risk of personal / public safety or property damage, leave the valve in the open position and await the arrival of utility personnel. 9.9. If a valve is closed, it must NOT be re-opened by anyone other than Enbridge Gas Distribution personnel. 10. Restoring Natural Gas Supply to Premises or Appliances 10.1. Once any natural gas supply valve has been closed by anyone, only an Enbridge Gas Distribution representative shall open the valve. The Enbridge Gas Distribution representative shall enter all premises to perform safety checks and restore service to appliances. 10.2. At incidents involving suspected faulty natural gas appliances and equipment, TFS personnel shall not perform services or repairs to any appliance or equipment 11. Natural Gas Refueling Stations 11.1. Most natural gas vehicles are fueled at natural gas refueling stations that are part of a standard public service station. There is a separate meter station, compressor and several rows of up to 40 storage cylinders (usually called a cascade). This compressor and the cylinders along with the controls are installed in a fenced compound. Emergency instructions, including the location of all emergency shutdown switches and control valves are clearly posted at each station. 11.2. A fire or natural gas escape at a station can be controlled by shutting off power to the compressor at the clearly marked emergency shutdown switch. There may be up to three switches, depending on the size of the station and any one switch will shut down the system. 11.3. Fire can be controlled by shutting off the natural gas supply at the meter or at the valves indicated in the stations emergency instructions. 12. Natural Gas Vehicles 12.1. The majority of vehicles converted to run on natural gas are dual-fueled, capable of running on either natural gas or gasoline. 12.2. The natural gas fuel is stored as a compressed gas rather than as a liquefied gas (such as propane) in cylinders constructed of steel, or steel and aluminum reinforced with fibreglass wrapping. In the near future the cylinders may be entirely constructed of fibreglass with different storage mediums inside such as activated charcoal to enable lower storage pressure. File Code: G-NATU Page 5 of 6  STANDARD OPERATING GUIDELINE 12.3. The natural gas fuel is usually stored in the cylinder at a temperature compensated pressure of 20 700 kPa at 21°C. Maximum filling pressure is 24 800 kPa. 12.4. The natural gas cylinders are normally mounted in the trunk of a car, or under the frame or in the interior of a van or truck. The cylinders have a capacity of 60 litres and weigh approximately 55 kg. They hold the equivalent of 17 litres of gasoline. However, cylinders of much larger sizes from 35 to 120 litres are available for larger vehicles. TTC natural gas buses have even larger cylinders of 1600 litres that are mounted on the roof. 12.5. If the fuel system is damaged by impact in an accident all natural gas vehicles are equipped with master shut-off valves that can turn off the supply of fuel. Generally this valve is found on or near the cylinder itself or under the hood. 12.6. If the valve cannot be reached, the situation should be handled simply by keeping people and all potential sources of ignition well away from the escaping natural gas. 12.7. Natural gas cylinders on vehicles contain compressed vapour only. If the vehicle is on fire, the natural gas cylinder will not burst (BLEVE) as it contains no liquid. Every cylinder is equipped with a pressure relief device (PRD) in the form of a burst disc. This valve is designed to vent natural gas automatically to the atmosphere at a controlled rate, before the temperature and pressure in the cylinder reach potential danger levels. The venting could add to the fire but the cylinder is unlikely to rupture. 12.8. Burst discs do not reset and the entire contents of the venting cylinder will be exhausted to the atmosphere. 13. Special Operations 13.1. Questions and recommendations regarding natural gas incidents should be directed to the Special Operations Section, Professional Development and Training Division. ATTACHMENT(S) N/A RELATED SOGS G-HAZD — Hazardous Materials Incidents – Decontamination Operations G-OAEN — Other Agencies (Non-Emergency) – Ministry of Environment (MOE) G-OAGC — Other Agencies (Non-Emergency) – Gas Company File Code: G-NATU Page 6 of 6