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EMERGENCY PROCEDURES NATURAL GAS

March 29, 2019

NATURAL GAS EMERGENCIES AND FIRES

EMERGENCY PROCEDURES March 29, 2019 NATURAL GAS

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Contents

1. PURPOSE........................................................................................................................... 5

2. BACKGROUND ................................................................................................................ 5

3. PROPERTIES..................................................................................................................... 5

4. GAS SYSTEM INFRASTRUCTURE ............................................................................... 6

4.1 GATE STATIONS.............................................................................................................. 6

4.2 TRANSMISSION MAINS ................................................................................................. 7

4.3 DISTRIBUTION MAINS, REGULATOR STATIONS & MAIN VALVES.................... 7

4.4 GAS SERVICE & CURB VALVES/SERVICE VALVES................................................ 9

4.4.1 EXTERIOR GAS SERVICE VALVES & HEAD OF SERVICE VALVES................... 10

4.4.2 REGULATORS & PECK VENTS................................................................................... 11

4.4.3 METERS........................................................................................................................... 12

4.4.4 INTERIOR RISER VALVES........................................................................................... 13

4.4.5 APPLIANCES & APPLIANCE VALVES ...................................................................... 13

5. STRATEGY...................................................................................................................... 15

6. TACTICS.......................................................................................................................... 16

6.1 RESPONSE....................................................................................................................... 16

6.2 APPARATUS POSITIONING......................................................................................... 16

6.3 ON-SCENE SIZE-UP....................................................................................................... 16

6.4 PERSONAL PROTECTIVE EQUIPMENT, GAS DETECTORS & METERS ............. 17

6.5 INVESTIGATION............................................................................................................ 18

6.6 DETECTION .................................................................................................................... 20

6.7 MITIGATION................................................................................................................... 21

6.7.1 VENT................................................................................................................................ 21

6.7.2 ELIMINATE IGNITION SOURCES............................................................................... 21

6.7.3 ISOLATE/CONTROL LEAK .......................................................................................... 21

6.7.4 CONFIRM LEAK HAS STOPPED ................................................................................. 26

6.7.5 TRANSFER OF OPERATION TO UTILITY COMPANY ............................................ 26

7. MAJOR GAS EMERGENCIES....................................................................................... 27

7.1 INDICATORS .................................................................................................................. 27

7.2 EXPLOSION PROFILE ................................................................................................... 27

7.3 RESPONSE POLICY ....................................................................................................... 28


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8. MAJOR GAS EMERGENCY STRATEGY .................................................................... 29

9. MAJOR GAS EMERGENCY TACTICS ........................................................................ 33

9.1 OPERATIONS INSIDE OF THE POTENTIAL BLAST ZONE .................................... 33

9.1.1 SAFETY INSIDE OF THE POTENTIAL BLAST ZONE .............................................. 34

9.1.2 EQUIPMENT ................................................................................................................... 34

9.1.3 RAPID EVACUATION ................................................................................................... 34

9.2 OPERATIONS OUTSIDE OF THE POTENTIAL BLAST ZONE ................................ 35

9.2.1 WATER SUPPLY/ LINE PLACEMENT ........................................................................ 35

9.2.2 POWER REMOVAL........................................................................................................ 36

9.2.3 LOCATING VALVES ..................................................................................................... 36

9.2.4 VENTILATION................................................................................................................ 37

10. INCIDENT COMMAND ................................................................................................. 38

10.1 CHIEF OFFICER POSITIONS ........................................................................................ 40

11. ADDITIONAL RESOURCES.......................................................................................... 41


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1. PURPOSE

This guide describes gas system infrastructure to aid size-up and operational awareness, and to improve operational efficiency. Most importantly, the guide is intended to help assess the degree of risk present and take appropriate action at gas emergencies. As an operational guide it details how to investigate alarms for gas leaks and make decisions based on current best understanding and practices. While the tactics presented cannot eliminate risk, when adhered to they will help ensure decisions are based upon a rational approach. All members are encouraged to utilize this guide.

2. BACKGROUND

NYC is relying more and more on natural gas for its energy needs. The rate of households converting to gas in NYC is among the greatest in the Nation. Much of the gas system infrastructure in NYC is also some of the oldest in the Country. Construction, whether new, renovation, or maintenance-related, is also occurring at a tremendous rate and can damage gas systems if not properly planned and executed.

As first responders we are called to respond to leaks and fires involving natural gas. Gas leaks, minor and major, are occurring more frequently. Responses that resolve as gas leaks have doubled relative to a ten-year baseline in the last several years. Most gas emergencies are resolved by simple mitigation; rarely does the response involve complex, vital components of the gas delivery system. Some responses, however, involve situations that can put the public and our members at great risk, sometimes without the degree of risk being apparent.

3. PROPERTIES

Natural gas is a hazardous material classified as a “Flammable Gas” and exhibits the following properties:

Comprised mainly of methane but also contains propane, ethane and nitrogen.

Natural gas is a hazardous material classified as a Class 2, Division 1 substance. It containshigh stored energy and is extremely flammable.

Depending on the mixture, the explosive range is 5% - 15%.

Colorless and odorless; however, to aid in detection, mercaptan is added to natural gas as anodorant, giving it a “rotting” smell. Mercaptan can be masked by other odors, stripped bychemicals or removed as natural gas passes through material such as soil. In addition,members operating in a gas environment can become desensitized to the smell, giving thefalse impression that the natural gas condition is no longer present.

Significantly lighter than air.

Non-toxic, but in sufficient quantity natural gas can displace oxygen in an enclosed spaceand cause asphyxiation.


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When natural gas ignites, it undergoes a rapid increase in volume. If confined, the pressure,due to the volume change, will create an explosive force. A greater amount of gas indicatesgreater destructive potential. Two cubic feet of natural gas has the approximate energypotential of 1 pound of TNT.

When unconfined (outdoors), natural gas will burn rapidly, without triggering explosivepressure.

4. GAS SYSTEM INFRASTRUCTURE

NYC uses over two billion cubic feet of natural gas every day, supplying two-thirds of our total energy needs. Natural gas is supplied to NYC by three interstate pipelines and several interconnections under the management of several distributers.

Con Edison Gas distributes natural gas to Manhattan, the Bronx, and in Queens, generallynorth of the Grand Central Parkway.

National Grid distributes gas to Brooklyn, Staten Island and in Queens, generally south of theGrand Central Parkway.

There are facilities in NYC used to store liquefied natural gas (LNG) by these Utility Companies for use during peak demand or when there are interruptions in supply.

4.1 GATE STATIONS

All of these facilities have moderate security protecting complex equipment (filters, heaters, regulators, meters, valves and relief vents) needed to regulate supply of natural gas to the City. The facilities have remote monitoring by the Utility Company’s Gas Control Centers but generally have no permanent on-site personnel. Any event in these facilities should be considered an industrial facility emergency and actions should be limited to life saving and protecting exposures until the Utility Company has been consulted. CIDS and Pre-Incident Guidelines (PG) should be used appropriately to pre-plan for major events.

Hellgate Gate Station, Bronx, Dec. 1989,

5th Alarm, Transmission Main Fire


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4.2 TRANSMISSION MAINS

From the Gate Stations natural gas is delivered via Transmission Mains to area Regulator Stations which can have above-ground and/or vaulted equipment. At Regulator Stations pressure is reduced and the gas is routed to various customers via Distribution Mains.

4.3 DISTRIBUTION MAINS, REGULATOR STATIONS & MAIN VALVES

Natural gas is piped to customers along Distribution Mains which may be high, medium or low pressure. Regulator Stations reduce pressure between Distribution Mains of different types.

High pressure Distribution Mains are made of steel and are generally installed below majorroads.

Medium and low pressure Distribution Mains are made of steel, plastic, or, if older, cast iron.Cast iron pipe is currently being replaced as it is prone to corrosion and failure, being brittlewith low tensile strength.

High and medium pressure Distribution Mains have control valves that are exercised (partially) on a schedule to ensure working order. These valves are generally found near street corners, but may also be located along the street or on the sidewalk. Main valve covers are larger than curb valve/service valve covers to allow servicing and may be round or square.

Marker indicating buried Transmission or Distribution Main


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Con Edison Gas main valves have ID numbers on tags inside of the valve cover.

National Grid main valve covers are identified by an ID number stamped on the North side of the collar, underneath the cover; however, these numbers may be difficult to see.

Low pressure (¼ psi) Distribution Mains generally do not have valves and isolating sections of low pressure Distribution Mains requires plugging or “squeezing off” the pipe while still under pressure (live). Only the Utility Company can safely plug or squeeze-off Distribution or Service Mains due to spark hazards.

Con Edison Gas Main Valve Covers

Con Edison Gas Main Valve Tag


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4.4 GAS SERVICE & CURB VALVES/SERVICE VALVES

Gas service is the piping supplying individual buildings. Gas service pipe generally runs at right angles off of the Distribution Main, into the building. There is usually a curb valve/service valve (below grade) or an exterior gas service valve (above grade) between the Distribution Main and the building.

Curb valves/service valves are usually found on the sidewalk side of the curb and these valves shut the gas supply to the entire building. They are usually recessed in from the curb and are covered with a 4” X 4” square or round, brittle concrete or steel cover which may be sitting on top of a plastic or wooden plate.

On the National Grid “Long Service” system, the curb valve/service valve is sometimes located across the street from the building it supplies, and may be found in the street. This type of curb valve/service valve can be identified by an arrow cast into the cover pointing to the building it supplies.

Some gas service piping supplies gas to the building without having a curb valve or service valve. A “NC” stamped on a tag near the service meter indicates there is no curb valve or service valve. An “EFV” stamped on a tag near the service meter indicates an “excess flow valve” exists in line on the service pipe. The EFV should limit or stop excess flow down pressure from it.

Care must be taken to differentiate between curb valves/service valves and main valves. The ramifications of closing, or damaging, a main valve are far greater than closing or damaging a curb valve/service valve which controls service to only one building.

Curb Valve/Service Valve Cover Curb Valve/Service Valve


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4.4.1 EXTERIOR GAS SERVICE VALVES & HEAD OF SERVICE VALVES

Exterior Gas Service Valves control the supply of gas to meters installed on the outside of buildings. If an exterior gas service valve is present, no curb valve/service valve is required.

Head of Service Valves control the supply of gas to meters installed on the inside of buildings.

National Grid Long Service Curb Valve/Service Valve Cover

Service Regulator

Exterior Gas Service Valve


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4.4.2 REGULATORS & PECK VENTS

Natural Gas Service

Typical house appliance pressure is ¼ psi.

A few commercial customers receive gas at 1 to 3 psi.

There are a small number of large facilities that utilize full line pressure, especially for powergeneration.

Service Regulators are usually located before the gas meter on medium and high pressure systems to reduce gas to low pressure (¼ psi).

Peck Vents are installed on systems supplied by medium or high pressure to vent excess gas to the exterior if the service regulator fails. They may have a red cap. There should normally be no odor of natural gas at a peck vent. If an odor is detected, you must investigate to determine the source.

Multiple Peck Vents on a Building with Multiple Service Regulators


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4.4.3 METERS

Gas Meters can supply individual occupancies or entire buildings. Before the meter there should be a ¼ turn meter valve that controls the supply of natural gas to the meter.

Single Master Meter

Some multi-occupancy buildings have only a single master meter supplying natural gas to alloccupancies. Shutting it down will shut gas to the entire building. Sometimes the UtilityCompany will have two master meters adjacent to one another so a master meter can beserviced or replaced without interrupting service to the building. The valves to both meterswould need to be closed to shut supply to the building.

Multiple Meters

Other buildings have multiple meters, each supplying natural gas to a different occupancy ortenant.

Note: Some older apartment buildings may have individual gas meters located inside of eachapartment served, and in some buildings, meters may be found in the public hallway.The presence of gas piping or meters in a public hallway requires appropriate enforcementaction (refer to the BISP Manual).

Service Meter

¼ turn Meter Valve

Service Regulator


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4.4.4 INTERIOR RISER VALVES

Often there are interior gas riser valves coming off of the master meter, typically near the ceiling of the cellar. These can be used to isolate a section of the building instead of shutting service to the entire building.

4.4.5 APPLIANCES & APPLIANCE VALVES

All natural gas appliances should have ¼ turn valves between them and the building/tenant natural gas supply pipe. The pipe connecting the appliance to the supply pipe may be rigid or flexible.

Commonly found natural gas appliances include:

Stoves/Ovens Hot Water Heaters

Barbecues Window/Wall-Mounted Gas Heaters

Refrigeration Fireplaces

Dryers Outside Decorative Lighting

Interior Riser Valves Meter Valve


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Furnaces and Boilers: Many large heating plants use a significant amount of natural gas. These systems may require assistance from building engineers and Utility Company personnel to mitigate emergencies.

Air Conditioners: Large, commercial units are often located on rooftops or setbacks. Some HVAC units are combination units, housing heating units using natural gas and conventional cooling units. Some large units may have chillers using natural gas as part of the condensation-evaporation cycle. Other, less common, units use natural gas in the heat exchange process. A failure in any part of these large, commercial air conditioning units can allow natural gas to leak and spread throughout the entire HVAC system.

Lighting: In the past, natural gas was used for illumination inside of certain buildings. These old gas lines were sealed with wax and, over time, this wax can deteriorate resulting in a gas leak. These types of leaks may be difficult to locate.

Direct Vent Appliances: Direct vent boilers and hot water heaters have become prevalent throughout the city. They may be located anywhere within a structure and are vented by a short length of pipe through an exterior wall. Direct vent window and through-the-wall heaters may also be used to heat individual occupancies.

Old gas line for lighting run along the ceiling

Direct Vent Through-the-Wall Heater


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5. STRATEGY

Most natural gas emergencies are resolved through investigation and simple mitigation. On occasion, a response can elevate to a Major Gas Emergency, at which point FDNY strategy should focus on securing life safety (evacuation).

The following conditions are indicative of a Major Gas Emergency and may require changing from a simple mitigation strategy to one that emphasizes all efforts on securing life safety (including utility personnel and first responders).

o Serious damage to major components of the gas infrastructure (i.e., a Master Meterservicing many appliances, gas service pipe, Main Valves, Distribution Mains, etc.)

o 10% LEL or greater detected outside or inside (see section 6.4 for best practices onmetering tactics).

o Elevated natural gas reading (20% LEL or greater) in an unvented, subsurfacestructure (manhole, sewer, etc.)

o Gas present in two or more subsurface structures (manhole, sewer, etc.)

o Indications of gas migrating into a building from an outside source

o Gas leaking inside of a structure and the controlling valve cannot be located or isinoperable

o Gas leaking or present inside of a wall or void in a structure

Atmospheric Monitoring:

Since natural gas readings will generally be more concentrated closer to the source/leak, members need to be aware of the location they are taking readings. When reporting results, members must also report the exact location and should state if they are in proximity to any natural gas appliance.

For example:

"Ladder 38 to Command, we have a reading of 7% LEL in the lobby."

"Ladder 4 to Command, I am in the cellar by the crack in the foundation and have 15% LEL."

Generally, the presence of natural gas in the lobby of a building would be more of a cause for concern than the same reading in the kitchen, at a stove with a defective natural gas connection. The further from the source/leak that natural gas has travelled, the more dangerous the situation.


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6. TACTICS

6.1 RESPONSE

Gather information available from the response ticket. Construction type, occupancy, caller location and description should be combined with the responder’s knowledge of natural gas systems to increase situational awareness (i.e., calls to laundromats may differ from calls to private dwellings as they have different natural gas systems).

Gather updated information from the dispatcher while responding, as appropriate. New dispatch policy requires the FDNY dispatcher to notify the Gas Utility Company upon receipt of the alarm (before FDNY arrival on the scene). The Gas Utility Company is required to give an estimated time of arrival (ETA). Gas Utility Company response times are monitored by the New York State Public Service Commission and are typically within 30 minutes.

6.2 APPARATUS POSITIONING

If a strong odor is present on approach, stop and meter the area. If the meter displays 10% of the LEL, this may indicate a potentially serious leak and may require treating the incident as a Major Gas Emergency.

The apparatus should not be positioned in front of the reported leak location. In addition, units should avoid positioning over manholes and sewers. The purpose of positioning apparatus in this manner is to protect members while keeping curb valves, service valves, and main valves clear in the event of a significant leak. Additional units shall stage at street corners, and only enter into the block when appropriate.

6.3 ON-SCENE SIZE-UP

Structure: Upon arrival size-up the building, occupancy type and overall condition. The age and condition of the building may help indicate the condition of natural gas equipment inside. Vacant or untenanted buildings require a closer evaluation as slow leaks often go unnoticed over long periods of time. Buildings under construction or renovation require special attention as well, as damaged or faulty natural gas systems are often found in these structures.

Street: Be cognizant of signs of recent street work or on-going work (street excavation, plumbing truck in front of a building, etc.)

Note: Vent holes, otherwise known as prospecting “bar” holes, are a series of roughly 1” holes in the pavement and indicate recent Gas Utility Company work.


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Serious gas leaks generally originate in the following ways:

Excavation work: Pipes can be damaged from direct contact and/or tension on the pipe as aresult of work. Failure can be some distance away from the excavation, (i.e., in a servicedbuilding). This can occur some time after the excavation has been filled in.

Mechanical failure (AKA human error): Mechanical failure resulting from work done by alocal plumber.

Subsurface leak: Pipe failure can be caused by undermining, corrosion or arcing fromadjacent electric feeder cables. Many serious leaks originate from below grade and migrateinto buildings along conduit and sewer lines.

Undetected small leak: Leaks may go unnoticed in confined areas (plenum space, crawlspace, etc.) or in vacant or untenanted buildings/building sections.

6.4 PERSONAL PROTECTIVE EQUIPMENT, GAS DETECTORS & METERS

The Department has provided all Ladder Companies with two types of natural gas investigative tools. One is a Natural Gas Detector (see Addendum 5); the other is a Natural Gas Meter (see Addendum 2). These two tools complement each other and both shall be utilized when investigating suspected natural gas leaks. Monitor continuously from the start. Natural gas detectors and meters require “warm-up” times in fresh air; it is good practice to power on these devices before arrival on scene.

The Natural Gas Detector is used to determine the location of a natural gas leak. This device does not have an LCD nor can it quantify gas levels. It uses an audible tick that increases in frequency as it approaches the source of escaping gas. The Natural Gas Detector detects natural gas at low levels. For this reason, it is the superior tool for locating leaks in appliances (stoves), supply piping (joints) and points of entry into a building (cracks). In a hallway with multiple locked doors, it is an excellent tool for identifying which apartment is involved. Simply pass the detector’s probe around a doorframe’s upper area while listening for an increase in the detector’s audile tick.

The Natural Gas Meter is used to determine the amount of gas present in an area. It visually displays the level of gas on an LCD in % LEL. The Natural Gas Meter is a superior tool for identifying areas in which it is no longer safe to operate. Tactically, this device should not be used at an appliance, pipe or crack as high levels of gas are expected at these locations. The best practice is to measure readings at a location high and in the middle of the room of the suspected leak; this is the % LEL to be reported to the IC.

Members shall wear their personal protective equipment (PPE). Even small amounts of natural gas can cause serious injuries to unprotected members from flash fires. Chief and Company Officers shall ensure strict compliance with the policy outlined in AUC 220 Self Contained Breathing Apparatus as it pertains to operating in an IDLH atmosphere.


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6.5 INVESTIGATION

The first priority at natural gas emergencies is to ensure there is not a Major Gas Emergency. This is followed by locating and mitigating minor leaks.

1. Outside Calls

Interview the caller or a competent on-scene individual. Acquire updated information from the dispatcher when required. Using detectors and meters, investigate surrounding subsurface structures such as manholes and sewers.

If gas is detected, notify the proper Utility Company through the dispatcher and meter below-grade areas and utility rooms of adjacent buildings, with emphasis on points of entry of utilities, sewer line clean-out pits and cracks in walls facing streets.

“Points of Entry” are locations where utility pipe/conduit of any type pierces the wall of the building and are commonly located in the meter room, but may be found elsewhere in the building. Subsurface gas leaks often enter buildings via these points.

Note: Utility Companies may refer to a point of entry as a “P.O.E.”










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2. Inside Calls

Venting may have been initiated before FDNY arrival.

If members cannot find the leak quickly, natural gas may approach a dangerous level. Natural Gas Detectors are sensitive enough to detect small leaks and may effectively detect a leak in a less contaminated area. A safer procedure may be to vent while searching for the leak and if the leak is not located, units can continue their investigation until the arrival of the appropriate Utility Company. When detector activation and meter reading were present, it is not acceptable to leave the scene of an “odor of gas” response after the odor has dissipated without mitigation or coordination with utility company representatives.

Natural gas may be leaking into areas that are difficult to sample such as wall spaces, plenums, crawl spaces, etc. Consider apparent levels (strength of odor, activity on detector, readings on meter, etc.) in the general atmosphere and anticipated location of the leak. When necessary, make inspection holes to access those areas. Utility Companies and FDNY Haz-Mat Company 1, Haz-Mat Technician Units, Squad Companies and SOC Support Ladder Companies have meters proficient in sampling hard-to-reach areas including wall and ceiling plenum spaces, subsurface structures, below sidewalks through expansion joints, subgrade soil, etc.

If natural gas is present in an HVAC system, examine rooftop and setback HVAC equipment for gas leaks, even if remote. Shut down HVAC fans and determine if the odor dissipates; this may indicate a leak at HVAC equipment or near the air intake for the HVAC system.

Gas, electric, and water conduits enter buildings through the wall

Sewer clean-out pits

Cracks in wall, floor


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Ladder Company Inside Team: Activate the Natural Gas Detector and Natural Gas Meter prior to investigating.

All investigations warrant the use of all available gas detectors/meters on scene.

Proceed to the reported location/caller noting odors, information gathered and detector/meteractivity.

If any natural gas levels are displayed on the Natural Gas Meter upon entering thebuilding, or while proceeding to the reported location within the building, the insideteam should proceed directly to the basement/cellar to evaluate conditions.

Ladder Company Outside Team: If additional detectors/meters are available, activate detectors/meters prior to commencing

outside team investigation.

Proceed to the natural gas utility meter location. This may be a basement/cellar level utilityroom or on the exterior of the building.

Report conditions and operate as directed by the Ladder Company Officer.

Engine Company arrival prior to Ladder Company:

Activate the Natural Gas Meter prior to entering the building.

The Engine Officer should proceed to the reported location/caller noting odors, informationgathered and detector/meter activity. Report information to the Ladder Company Officer/Battalion Chief upon their arrival. Remaining Engine Company members should prepare tostretch a hoseline, positioned outside of the potential blast zone.

6.6 DETECTION

The main mission is to ensure there is not a major leak. Secondary is mitigating minor leaks, which still have the potential for harm (mostly flash burns to nearby persons) or, if not stopped, can build up to become major leaks. A systematic approach is needed to avoid missing conditions that are unusual, complex or hidden.

Some responses are initiated from callers with knowledge of natural gas delivery/use systems and who know where the leak is, but are unable to stop it. Detection here involves making sure this is the leak and that there are no other leaks as well. Check all nearby natural gas appliances and piping. Use detectors and meters to confirm findings.

Most responses initiate from someone smelling mercaptan, the odorant added to natural gas just for that purpose. Some difficulties in investigating are:

Members may become desensitized to the odorant over time and may no longer smell it, evenif natural gas is still present. Other odors may mask the mercaptan. Migration through soilmay lessen the mercaptan’s effectiveness as an odorant. Use the Natural Gas Detector tolead you closer to the source of the odor. Call in other members to help search if becomingdesensitized.


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Gas is invisible; use the detector to lead you closer to the source of the odor.

Gas odors present in HVAC systems; examine rooftop and setback HVAC equipment for gas leaks, even if remote from the area. Shut down HVAC fans and wait to see if the odor dissipates; this may indicate a leak at HVAC equipment or near the air intake for the HVAC system.

6.7 MITIGATION

6.7.1 VENT

Vent the immediate area and continue to monitor natural gas levels using the meter anddetector.

6.7.2 ELIMINATE IGNITION SOURCES

Remove ignition sources near the leak utilizing a remote shut off. Removing power willcause a spark at the switch, which should only be done outside of the area that is within theexplosive range.

6.7.3 ISOLATE/CONTROL LEAK

Once a leak is found control the leak by shutting the closest valve that controls supply to theleak. If a leak cannot be controlled by operating the appropriate valve consider:

o A leak or break in low pressure gas piping may be stopped or greatly diminished bytaping, or stuffing putty, rags, paper, etc., into the break. This tactic will not work onmedium or high pressure piping before the service regulator.

Note: Leaking plastic pipe (permissible by code for outside use) should not be touched orapproached. Natural gas flowing out of a broken plastic pipe generates static electricitywhich builds up on the inside and outside surface of the pipe. Coming near to, ortouching, a leaking plastic gas pipe could result in a spark that ignites the escaping gas.The Gas Utility Company has equipment to dissipate this static electricity.

Caution: Although easily folded, firefighters should not approach or attempt to fold a leaking plastic gas pipe


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Priority Order of Valve Closure

1. Appliance Valve

Usually located behind or alongside the natural gas appliance and connected by hardpiping or flexible metal tubing. The appliance may have to be moved to access it.Be careful not to damage plumbing on appliances connected with rigid pipe.

Most natural gas shutoffs are of the ¼ turn variety and can easily be shut off using thefork end of a Halligan tool, vice grips or pliers to turn the wing cock valve ¼ turncounter-clockwise.

o Exercise caution when using the Halligan tool to shut the valve as too much forcecould result in a new gas leak at the valve location.

o When the key operating nut is parallel to the piping, it is in the open position. Whenit is perpendicular to the piping, it is in the closed position.

Open Closed


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2. Interior Gas Riser Valve

If the appliance valve is defective or the leak is on the supply side of the appliance valve,check for the presence of an Interior Gas Riser Valve in the basement/cellar near theceiling. This is a ¼ turn valve similar to the appliance valve and will disrupt less servicethan closing a Master Meter Valve would.

3. Individual Meter Valve

Each occupancy may have its own meter and natural gas supply can be controlled usingthe ¼ turn valve at this meter. This will shut the gas supply to the affected occupancy.

4. Master Meter Valve

A Master Meter Valve may control the flow of natural gas to just a few appliances (i.e.,in a private dwelling), or to many appliances (i.e., in an apartment house). When possible,avoid shutting the Master Meter Valve if it supplies many occupancies/appliances.To restore service to a large building or complex, the Utility Company must access eachaffected apartment to pressure test the piping and relight all pilot lights. (This may takeseveral weeks in larger buildings and is expensive for the Utility Company, as wellinconvenient for the occupants).

When possible, prior to shutting a Master Meter Valve notify the Utility Company andinquire as to possible alternatives (i.e., plugging/taping the leak, venting pending arrivalof the Utility Company, etc.).

Note: This does not preclude a unit from shutting a Master Meter Valve if natural gaslevels are still rising despite other methods (i.e., venting, plugging/taping) and the MasterMeter Valve is the closest valve controlling gas supply to the leak.

A Master Meter may have a second Master Meter adjacent to it. This second meter isused in the event of a malfunction in the primary Master Meter in use. The UtilityCompany can switch service over to the second meter without disrupting service to thebuilding. Consult with the Utility Company to correctly bypass an impaired meterwithout disrupting service, or for advice on shutting both Master Meter Valves, whennecessary.

5. Head of Service Valve

Building Service Valve: This valve is found just inside of the building where the naturalgas service enters and will usually be a ¼ turn valve. When the meter or meters arelocated outside, the valve will be before the meter(s).

Exterior Gas Riser Valve: Exterior Gas Riser Valves are ¼ turn valves located on thenatural gas riser outside of the building, before any exterior meters. All external meterinstallations will have a riser valve installed prior to the meter. Each meter also has itsown shut-off valve (meter valve).


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6. Curb Valve/Service Valve

Although the FDNY is authorized to shut curb valves/service valves, it should only bedone as a last resort and in consultation with the Utility Company. Many valves are oldand require skill to shut to avoid breaking the valve. Newer, plastic valves can also beeasily broken if too much force is used. In addition, it is possible to turn the valve pastthe “shut” position, causing confusion as to whether or not the valve is closed. If the curbvalve/service valve on a low pressure system becomes inoperative, mitigation of the leakwill involve a Utility Company construction crew ripping up the street to isolate/repairthe leak. If the curb valve/service valve of a medium or high pressure distribution systembecomes inoperative, mitigation of the leak will involve shutting the Main Valve,possibly disrupting a large area which may include critical facilities (i.e., hospitals,nursing care facilities, etc.). Contact the appropriate Utility Company ControlCenter when necessary to control a leak using the curb valve/service valve.

The curb valve/service valve is usually found on the sidewalk side of the curb and shutsthe natural gas supply to the entire building. It is generally recessed in from the curb, butmay be in the street. It is usually covered with a 4” X 4” square or round, brittle concreteor steel cover which may be sitting on top of a plastic or wooden plate. To shut thevalve, remove or break the cover and plate.

Note: The curb valve/service valve may have been covered with concrete or grass andnot be visible.

Gas Shut-Off Key - The gas shut-off key consists of a long shaft with a uniquely shapedwrench socket on either end that is placed onto the curb valve’s/service valve’s operatingnut. Look into the valve box. Before using the key, determine which end is suitable forthe valve that is being shut down. Attach the proper end of the gas key onto the valve.Before turning the key, place chalk or some other mark near the valve to indicate the startpoint. This will assist in noting when a ¼ turn is complete.

A white valve is plastic and easily broken by excess force. National Grid supplies awhite, plastic insert for shutting down plastic valves. For Con Edison plastic curbvalves/service valves, use the gas key as is.


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It may be difficult to discern between a curb valve/service valve and a Main Valve.FDNY is not permitted to shut a Main Valve. If a Main Valve fails, shutting the nextvalve up in the system may cause a major disruption in natural gas supply to an entireneighborhood and multiple, critical occupancies. In addition, shutting the Main Valvemay not stop the leak as multiple Main Valves may need to be shut if the system issupplied from more than one direction.

o Con Edison Main Valves should have a tag inside of the valve housing with anI.D. number, indicating these are NOT curb valves/service valves.

o National Grid Main Valves can be identified by an ID number stamped on theNorth side of the collar underneath the cover, indicating these are NOT curbvalves/service valves.

If a leak is serious enough to consider shutting down a Master Meter Valve, Head ofService Valve or curb valve/service valve, consider treating the incident as a MajorGas Emergency.

7. Main Valve

Main Valves are usually located on the street side of the curb and are used to isolate largesections of the natural gas main. They can look like curb valves/service valves butcontrol distribution lines usually running under the street (these lines can also be foundunder sidewalks and unpaved areas).

Note: FDNY is not permitted to shut a Main Valve.

Firefighters close a curb valve/service valve using a gas shutoff key and a Halligan tool for leverage.


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The cover may be round or square and come in a variety of sizes (typically 9” or larger).

o Con Edison Main Valves should have a tag inside of the valve housing with an IDnumber.

o National Grid Main Valves can be identified by an ID number stamped on the Northside of the collar, underneath the cover; however, these numbers may be difficult tosee.

Shutting a single Main Valve may not stop the flow of gas as distribution piping can befed from more than one direction. The Utility Company will refer to maps to determinewhich valves to shut. It may be necessary to shut several Main Valves, some possiblyremote from the building or area with the natural gas emergency, in order to isolate asection of piping.

Shutting a Main Valve may disrupt natural gas service to a large area and/or criticallocations. Gas service may not be restored to the area for several weeks.

Main Valves are usually not present on low pressure gas systems. Stopping the flow ofgas in a low pressure main will require the street mains to be excavated and stoppersinstalled, which may take several hours.

6.7.4 CONFIRM LEAK HAS STOPPED

A distinct and continuous drop in natural gas levels must be present.

o A spray bottle of soapy water can be used to test suspected leaking plumbing and confirmvalve closure has stopped the leak.

o A gas detector/meter may slow or stop, indicating the leak has slowed or stopped.

6.7.5 TRANSFER OF OPERATION TO UTILITY COMPANY

Transmit to the dispatcher a brief description of conditions found, actions taken and personsleft in charge, as well as the appropriate radio code. Report the location of the natural gasvalve shut for relay to the Utility Company.

Remain on scene until no natural gas remains (zero readings on the meter, no activity on thedetector, gas odor dissipated, etc.). If given a reasonable ETA by the Utility Company andadequate resources are available, the Incident Commander (IC) should consider having a unitremain on scene awaiting the Utility Company’s response. Utility Company employees canconfirm the leak has stopped, implement temporary repair or lock-out/tag-out the defectivegas system.


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7. MAJOR GAS EMERGENCIES

A Major Gas Emergency is any gas emergency that, in the opinion of the Incident Commander, requires special resources and tactics to mitigate and/or poses a threat of a major explosion or fire.

7.1 INDICATORS









7.2 EXPLOSION PROFILE

An Explosion Profile is the size-up of a building’s explosion potential based on the current amount of natural gas and gas energy within the structure. To determine this, the amount of natural gas present and the size of the area the gas is accumulating in should be estimated.

Example 1: A recently extinguished pilot light on a stove may read 100% LEL if the meter is placed directly on the pilot light. If there is no natural gas accumulation in the room, the explosion profile is not a concern. Ignition of a small amount of gas will simply re-light the pilot light.

Example 2: A natural gas leak from a damaged, flexible gas hose which passes through a kitchen cabinet to supply a stove may read 100% LEL inside the small cabinet but may read only 1% LEL in the actual kitchen. An explosion of the natural gas in this situation may cause the cabinet doors to blow off and a flash fire from the cabinet, but not an explosion that would destroy the building. This may be considered a minor explosion profile.

Example 3: A major explosion profile might include a 2-story building in which a natural gas line was damaged by a contractor and has filled the building with a significant amount of gas which is in the explosive range. Ignition of gas at this level may cause a major explosion of the building.


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7.3 RESPONSE POLICY

A 10-75 and 10-80 Code 1, specifying a “Major Gas Emergency,” should be transmitted to the dispatcher when an incident is determined to be a Major Gas Emergency. This signal will serve to both detail the seriousness of the emergency as well as assign appropriate resources; a response matrix with a tailored Incident Command Structure and resources with enhanced metering capability. The IC may modify the assignment to meet incident needs after careful consideration and consultation with the Haz-Mat Battalion via cell phone or 800 MHz radio (preferred). Incident particulars may be uncertain early on, involve complex components and have hidden risks.

When a 10-75 and 10-80 Code 1, specifying a “Major Gas Emergency,” is transmitted, the IC should also transmit the location of the designated Command Post and Staging Area. Incoming units not requested by the IC for immediate deployment should report to the Staging Area. The officer not put to work by the IC should be the Staging Area Manager until relieved by the assigned Battalion Chief designated as the Staging Area Manager. As soon as possible, the IC should transmit to the dispatcher a concise description of the conditions, % LEL of meter readings taken with the locations, and tactics implemented.

When required, the transmission of a 10-75 and 10-80 Code 1 for a “Major Gas Emergency” will also prompt the dispatcher/FDOC to notify the appropriate:

Borough Commander/City Wide Tour Commander

Gas Utility Company

Electric Utility Company

NYC Emergency Management (NYCEM)

Bureau of Fire Investigation

Police Department

NYC Transit

Department of Buildings


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8. MAJOR GAS EMERGENCY STRATEGY

1. Outside Leak

Leaks from damaged, exposed low pressure natural gas mains should vent naturally, although secondary leaks may need to be addressed. Stopping a leak from a low pressure main will generally require the Utility Company construction crew plug or clamp (squeeze) the pipe to interrupt natural gas flow. The request should be made as early as possible to allow for the long reflex time for this resource.

Medium and high pressure natural gas mains present much greater risk as large amounts of gas will escape. A fire with an abundant and sustained heat release rate will occur if an uncontrolled medium or high pressure main leak ignites. Stopping a leak generally involves the Utility Company finding and operating the correct upstream valves to interrupt the flow of natural gas.

In either case, proper procedure is as follows:

Establish the Command Post at a safe location and announce its location over the handie-talkie and Department Radio.

Evacuate the affected area and search for victims.

Control vehicular and pedestrian traffic to prevent entry into the operational area. Plan fornecessary access of Utility Company vehicles.

Check subsurface structures and surrounding basements/cellars for natural gas infiltrationfrom the original leak, or secondary leaks. Damage to a natural gas pipe at a constructionsite or excavation may result in additional damage to the gas pipe at other locations.If a backhoe pulls and/or breaks a gas service pipe, it may also have dislodged the servicepipe from the building, separated a coupling and/or pulled the pipe from the DistributionMain in the street. It is possible to have a natural gas leak where the backhoe was operating,another leak at the building line or in the building, and still another one at a coupling orwhere the service pipe connects to the Distribution Main. These additional leaks can gounnoticed and accumulate to explosive levels. For these reasons, subsurface structures andsurrounding basements/cellars should be checked as soon as possible.

Set up precautionary hose lines to control possible extension in case the natural gas ignites.Large caliber streams should be considered as their reach and volume is appropriate fordefensive use. If the natural gas ignites, do not extinguish the fire. Avoid operating into theexcavation, as water accumulation here can impede isolation and repair. Cool adjacentstructures as necessary to prevent extension from radiant heat.

Remove ignition sources within the limits of safety. Coordinate with the Electric UtilityCompany directly or through the dispatcher.

Locate valve locations if outside of the potential blast zone. Create access for the UtilityCompany if blocked by vehicles, etc. (consider floor jacks, Hurst tool chains, NYPD Towing,resources through NYCEM, etc.) Relay valve identification numbers and locations to theUtility Company if representatives are not yet on scene.


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2. Subsurface Leak

For subsurface leaks use meters to determine how much natural gas has accumulated (the gas readings and extent to which gas has traveled). From this, an estimate can be made as to the location/size of the potential blast zone. Evacuate this area, keeping all personnel (including responders and Utility Company personnel) out of the potential blast zone except for direct, life-saving efforts.

Establish the Command Post outside of the potential blast zone and announce its locationover the handie-talkie and Department Radio.

Evacuate the affected area and search for victims.

Establish the potential blast zone and continue to monitor the perimeter for changes. Markthe potential blast zone with red, “DANGER DO NOT ENTER” tape and announce thepotential blast zone boundaries over the handie-talkie and Department Radio.

Control vehicular and pedestrian traffic to prevent entry into the operational area. Plan fornecessary access of Utility Company vehicles.

Meter readings should be taken at subsurface structures (sewers and manholes) as natural gasmay travel along sewer runs, and electric, gas or water conduit/pipe. Gas from a leaking pipemay travel some distance before finding a place to surface as pavement, snow or frozenground can trap it underground. These factors can make defining the potential blast zonedifficult.

As rapidly as possible, surrounding below-grade areas of adjacent buildings should besurveyed with meters. Natural gas may pass some buildings with little or no infiltration butenter others via points of entry and wall cracks. Do not assume buildings are clear untilproperly checked. Continue to monitor exposures throughout the operation.

Set up precautionary hoselines, as necessary.

Remove ignition sources within the limits of safety. Coordinate with the Electric UtilityCompany directly or through the dispatcher.

Locate valve locations if outside of the potential blast zone. Create access for the UtilityCompany if blocked by vehicles, etc. (consider floor jacks, Hurst tool chains, NYPD Towing,resources through NYCEM, etc.) Relay valve identification numbers and locations to theUtility Company if representatives are not yet on scene.


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Pathways of gas leak from subsurface pipe into subsurface structures

Pathways of gas leak from subsurface pipe into the cellar of a building


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3. Inside Leak

If the Natural Gas Meter displays any readings at the building entrance/first floor, the Ladder Company Inside Team should go directly to the basement/cellar to investigate. Do not delay by going to a caller on an upper floor.

Leak found

o If the leak is found and can be controlled by a valve or, on low pressure service (ormedium/high pressure service after the service regulator) by tapping/plugging, then doso.

o If the leak is found and levels can be kept at less than 80% LEL by venting, you maycontinue to operate.

o If levels can be kept at less than 80% LEL, remove ignition sources (shut breakers, pullfuses, shut off gas appliances, etc.) ONLY IF this can be done from an area notwithin the explosive range.

o If at any time gas levels reach 80% of the LEL or higher, treat the affected area as a“Potential Blast Zone.”

o If the leak has allowed natural gas to flow into a wall or ceiling space, there may be aconsiderable amount of gas in that space. General atmosphere readings will notaccurately reflect the amount of natural gas present in the concealed space. Considerhow much gas has leaked and the likelihood of stopping the leak and venting theconcealed space. If it is suspected that natural gas has been leaking for aconsiderable amount of time and is likely trapped in a void space, treat the affectedarea as a “Potential Blast Zone.”

Note: Utility Companies and FDNY Haz-Mat Company 1, Haz-Mat Technician Units(Engines 44, 165, 250, 274 and all Squad Companies) and SOC Support LadderCompanies are equipped with detectors designed for detecting natural gas in voids.

Leak not found

o If the leak is not found, investigate the structure’s natural gas meters; if one is showinghigh gas flow, shut it using the Meter Valve, Head of Service Valve or curb valve/servicevalve. When possible, always shut the valve closest to the leak.

o Treat the affected area as a “Potential Blast Zone” if levels cannot be limited to lessthan 10% LEL by venting and:

The leak cannot be found.

There are indications the leak is coming from an outside, subsurface source.


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9. MAJOR GAS EMERGENCY TACTICS

To estimate an incident’s explosive potential, consider how extensive the area is, as well as natural gas level readings and potential ignition sources present. Initial tactics should focus on determining how much gas has accumulated in a particular area. This will contribute to the “explosion profile” of the incident and will help determine the extent of the potential blast zone and evacuation required. The size of the potential blast zone shall include the area likely to be affected by structural collapse. This zone will be determined by the Incident Commander and identified by red, “DANGER DO NOT ENTER” tape.

Apparatus should not be located within the potential blast zone; however, do not enter apotential blast zone to move apparatus.

The number of members and time spent operating in the potential blast zone should be keptto a minimum and allow for rapid evacuation.

The potential blast zone will include streets, yards or alleys on all sides of the involvedbuilding. Exposures may be included in the potential blast zone if likely to be affected by anexplosion.

Other agencies should be prevented from entering the potential blast zone unless they areinvolved in direct, life-saving procedures; this includes Utility Company personnel.

Extreme care shall be exercised before re-entering a building that was in the potential blastzone. Natural gas levels in surrounding areas should be absent or low as the potential blastzone is redefined based upon all information gathered before allowing any members,including Utility Company personnel, back in.

At Major Gas Emergencies, the potential blast zone shall be considered an exclusion zone for all personnel and shall only be entered for direct, life-saving purposes.

9.1 OPERATIONS INSIDE OF THE POTENTIAL BLAST ZONE

Many tactics may be used at Major Gas Emergencies outside of the potential blast zone. Tactics used inside of the potential blast zone, however, should be limited. These tactics have as their objective:

The quick evacuation of likely occupants.

Minimum exposure of members.

Minimum time spent in the potential blast zone to obtain the first objective.

Tactics inside of the potential blast zone should be limited to rapid evacuation as detailed below. Removing ignition sources and venting are not options within the potential blast zone. No amount of reconnaissance, venting or power removal is worth a first responder’s life. Other than rapid evacuation no other actions inside of the potential blast zone should be warranted. All members should strive to GET OUT of the potential blast zone.


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9.1.1 SAFETY INSIDE OF THE POTENTIAL BLAST ZONE

Do not use door bells as this may trigger an electric spark; knock on doors.

Static electricity can cause ignition. Avoid standing on doormats inside of the building;likewise, avoid traversing across carpeted areas.

Known life hazards and people needing assistance should be helped using standard removaltechniques. Minimize the time spent inside of the potential blast zone.

Ensure only intrinsically safe equipment is utilized.

9.1.2 EQUIPMENT

Currently, the only FDNY-issued powered equipment that are intrinsically safe (can be usedin a potentially explosive atmosphere) are:

o Handie-talkies

o Natural Gas Detectors

o Natural Gas Meters

o Flashlights issued by the FDNY

Note: As a precaution, these devices should be powered on in a clear environment and remain on until returned to a clear environment.

Do not use any powered equipment that is not intrinsically safe inside of the potential blastzone. Thermal Imaging Cameras, Ventilation Fans, Cell Phones and Megaphones are notintrinsically safe.

Megaphones may be used outside of the potential blast zone to issue instructions to thepublic.

9.1.3 RAPID EVACUATION

Rapid evacuation will allow members to locate and rescue civilians from an explosiveenvironment, while limiting their exposure to potential extreme hazards. This is significantlydifferent from primary searches conducted at fires and is accomplished with as few membersin the potential blast zone as possible to cover the greatest area, and exit the potential blastzone in the shortest time possible. Evacuation should be via an available stairway; elevatorsshould not be used.

Rapid Evacuation is conducted by knocking on doors and moving from door to door to alertoccupants. The intent is to alert occupants to self-evacuate. Assistance can be provided topeople with special needs or those requiring assistance. If no one answers the door to an areaor apartment, members should move on to the next door. Forcible entry should only beaccomplished for a known life hazard and should not be attempted to access areas that showno signs of being occupied.

o When forcible entry is required in an explosive environment it should be accomplishedusing equipment and techniques that will limit the chance of causing a spark.


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o Conventional forcible entry involving the use of an axe to strike the Halligan is notpermitted. Entry should be conducted with the use of the adz end of the Halligan to gapand force the door and/or with the use of the hydraulic forcible entry tool (Hydra-Ram).

Occupants should be notified there is potential for a natural gas explosion and they are not toturn on lights or use cell phones or any other electronic devices and must evacuateimmediately by orders of the Fire Department.

In structures with elevators, occupants should be instructed to use the stairs and not theelevators unless the situation makes it impractical (e.g., gas leak on an upper floor of a high-rise residential building where FDNY members utilize elevators to evacuate civilians).Elevators in the potential blast zone are NOT to be used by civilian or FDNY personnel.Elevators create electric arcs whenever they are activated by the call button or signaled tomove.

The IC should consider the evacuation of all buildings in proximity to the incident locationwhen necessary. If these building are not located in the potential blast zone, operations suchas routine forcible entry, searches, venting and power removal can be conducted asnecessary. In addition to buildings, streets, sidewalks, public spaces, transit facilities, etc.,may need to be evacuated as a precaution and to clear areas for Utility Company constructioncrews. It is recommended that members quickly meter sewers, manholes and cellars as theyretreat from the original operating area after evacuating occupants.

Use plain-speak in preliminary and progress reports concerning the extent of the evacuationrequired and the need for assistance from NYPD, NYCTA, MTA, etc. NYCEM may becontacted directly to initiate/coordinate additional non-Fire Department resources.

9.2 OPERATIONS OUTSIDE OF THE POTENTIAL BLAST ZONE

9.2.1 WATER SUPPLY/LINE PLACEMENT

Units may be deployed to acquire water sources and stretch precautionary hose lines for theprotection of structures in the event of ignition or explosion. 2 1/2” hose and large caliberstreams are appropriate for these defensive positions and will allow greater reach.

All members, apparatus, appliances and hose should be positioned outside of the potentialblast zone.

Fog streams should not be used to dissipate natural gas venting outside of a structure; let thegas vent naturally.

The Utility Company may need to “plug” or “squeeze” a pipe with natural gas under pressureto stop a leak when a working valve is not available. The Utility Company utilizes speciallytrained employees to remove ignition sources. When required and consistent with safety, acharged fog hoseline may be used to protect workers placing the plug or operating the clamp.

Note: In all cases, the IC has the responsibility and authority to disapprove this tactic if itplaces Utility Company personnel or FDNY members at risk. Consult with the UtilityCompany to consider risks and options.


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9.2.2 POWER REMOVAL

At all major natural gas leaks, notify the dispatcher to have the appropriate Electric UtilityCompany respond and request an ETA.

Power cannot be removed from the potential blast zone without introducing the risk ofignition. Power removal always causes an arc at the point/location that power is removed.When turning off a light switch, an arc occurs in the switch. Similarly, when turning off acircuit breaker, an arc occurs at the circuit breaker. In addition, when power is removed,automatic generators, battery back-up burglar alarms, battery back-up hardwired smokedetectors and uninterrupted power supply units for electronics, when present, create smallarcs when they transfer from electric power to their alternate.

If FDNY members can remove power from the area of the leak before natural gas readingsreach 80% LEL, it SHOULD be done. In order to determine this, explosive readings must betaken wherever the highest concentration of natural gas has accumulated in the building.This is usually, but not always, near the source of the leak.

o Readings solely taken in an area remote from the leak cannot be used to determine it issafe to cut power.

o If any readings display levels of 80% LEL or greater, the opportunity to cut power hasexpired.

o When unable to locate the source of the leak, do not shut power.

After evacuation, and upon consultation with the appropriate Utility Companies, the IncidentCommander may consider allowing the Utility Company to cut power remotely from a utilitypole or manhole, even if natural gas levels are in the explosive range, when the followingconditions are met:

o All persons (including FDNY and Utility Company personnel) remain withdrawn fromthe potential blast zone. It is important to remain aware that even remote power removalmay trigger an explosion.

o The location from which the Utility Company is cutting power (utility pole or manhole)is not located within the potential blast zone.

9.2.3 LOCATING VALVES

When conditions permit, units may assist the Utility Company in locating valves and valvecovers.

The IC may be able to receive the general location of main valves by contacting the UtilityCompany’s Control Center. Access problems (vehicles, dumpsters on valve covers, etc.) canbe identified and resolved early.

Main valves have identification codes either on the collar underneath the valve cover or on atag under the cover. These codes should be relayed to the Utility Company Control Centerand Utility Company members on the scene.

FDNY members should be reminded not to operate any valve on the supply side of the curbvalve/service valve (i.e.; main valve).


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9.2.4 VENTILATION

If previous ventilation efforts have failed to prevent the area from becoming a potential blastzone (80% or more LEL gas leak location known or 10% or more LEL gas leak locationunknown) then the emphasis should be on rapid evacuation, not ventilation.

No area can be considered “too rich to burn” as these areas, at some portion of the affectedspace, are in the explosive range and will explode and involve the entire area if an ignitionsource is reached.

1. Natural Ventilation: Indoors

Natural ventilation can be accomplished by rapid evacuation teams as they move throughbuildings. Venting windows and doors as they are passed is permissible if doing so will notdelay evacuation. Do not remain in a potential blast zone simply to ventilate.

2. Mechanical Ventilation: Indoors

When HVAC intakes of a building are exposed to an outdoor natural gas leak, fresh airsupply fans should be shut down to prevent drawing gas in. Similarly, HVAC systemsshould be shut down when the equipment or area is involved in the gas leak. Consultbuilding engineers or competent in-house personnel.

3. Natural Ventilation: Subsurface Structures

Units may be directed to work with Utility Company personnel in pulling manhole covers tocreate paths for natural gas to vent to open air. In this case, members should abide by thefollowing provisions:

Sewer manhole covers may be removed by FDNY personnel with the approval of an on-scene Chief Officer. The Chief Officer should ensure the area is cordoned off to identifythe hazard of the open manhole.

Round, electric manhole covers can be removed by FDNY personnel only when all of thefollowing conditions are met:

o Requested by an on-scene Utility Company worker.

o Approved by an on-scene Chief Officer.

o The cover has been determined to be free of stray voltage by the on-scene UtilityCompany. The Chief Officer should ensure the area is cordoned off to identify thehazard of the open manhole.

Round manhole covers can be removed by two firefighters utilizing manhole hooks.Battalion vehicles carry two manhole hooks for use of this purpose.

Rectangular or square electric manhole covers shall not be pulled by FDNY personnel.

DO NOT pull any electric manhole covers (or any cover if there is doubt as to its type) when:

o There is a manhole fire in the area; or

o Smoking or arcing is observed in an electric manhole or transformer vault.


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4. Mechanical Ventilation: Subsurface Structures

In consultation with the Utility Company, the IC may deploy units to assist Utility Companypersonnel in mechanical ventilation of outdoor, sub-surface structures.

Both Con Edison Gas and National Grid have mechanical air movers that can exhaust airfrom sewers, manholes and subsoils via bar holes. The air movers use construction crewtruck compressors to blow air through a venturi, creating a negative pressure.

Con Edison Gas also has an intrinsically safe electric fan with a collapsible duct that canbe used to exhaust air from sewers and manholes.

This tactic may be used by a Utility Company to influence the migration of sub-surface leaks by creating negative pressure between the leak and the building at risk, allowing natural gas to vent to the atmosphere in an ignition-free area. This tactic may be useful in slowing gas migration towards building basements/cellars that may be at risk and are difficult to vent and/or evacuate such as large multiple dwellings, assisted living housing, hospitals, etc.

This tactic may also be employed to assist in venting by pulling air back through a subsurface structure to clear a building of natural gas so the building can be re-evaluated following evacuation. Extreme caution should be used before re-entering buildings that are in the potential blast zone.

10. INCIDENT COMMAND

1. Command and Control

Upon transmission of a 10-75 and 10-80 Code 1 for a “Major Gas Emergency,” asresources on the enhanced response arrive, the Incident Command System (ICS) shouldbe expanded as necessary and structured as detailed in this section. The complexity ofthe operation and risk to operating forces necessitates having a pre-plan utilizing thissystem. The Incident Commander should define the extent of the emergency; this isespecially true for sub-surface leaks, as well as excavation accidents due to the potentialfor multiple leaks as a result of pipe movement.

Units should be deployed as necessary and may be used for, but not limited to, thefollowing:

o Determining the extent of gas migration

o Evacuation

o Mitigation (venting, power removal, etc.)

The Gas Utility Company should be contacted by the IC to define the undergroundinfrastructure for subsurface leaks and determine any additional exposures that may beaffected. This contact can be made through the Utility Company representative on the sceneor by contacting the Utility Company directly from the Battalion/Division cellular phone.

The Utility Company’s Gas Emergency Control Center may be contacted for informationas to utility runs (gas and electric) to discern where natural gas may be migrating. Thismay help establish priority of reconnaissance for units.


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If there are indications that natural gas is migrating through the sewer system, NYCEMor DEP can provide information as to the run of the sewers in the area.

If there are indications that natural gas is migrating via subsurface infrastructure (electricor sewer lines), buildings served by those lines should be prioritized for rapid evacuation.

2. Potential Blast Zone and Rapid Evacuation

As soon as possible after determining a Major Gas Emergency is present, boundaries ofthe affected area should be established. Boundaries should be relayed to all membersusing recognizable physical features so that the extent of the boundaries are understood.As soon as conditions permit, the boundary should be marked with “DANGER DO NOTENTER” tape. The extent of the boundaries should be relayed over the DepartmentRadio for the benefit of units responding in as well as for relay to the Utility Company.

Units should be made aware of the potential blast zone when reporting in to theCommand Post or Staging Area. Any unit assigned to operate in or near the potentialblast zone should be reminded periodically of its location and boundaries by the IC.

Tasks should be conducted early on and initiated under the IC, usually the first arrivingBattalion Chief (BC). In accordance with the anticipated life hazard, units should beassigned to initiate the rapid evacuation of occupants from within the potential blast zone.All members must be apprised of the hazards of the potential blast zone. Whennecessary, and as soon as conditions permit, additional units should be designated anddeployed.

House/Building

Low Pressure Gas Service

Transmission Gas Main

Low Pressure Gas Main

Curb Valve

Main Valve

Map of natural gas utility runs


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Members should access exposures to define the extent of gas migration. It is expectedthat units not used for rapid evacuation will perform additional evacuation as well asreconnaissance and metering of an affected structure’s points of entry and sewer traps.

Buildings may be evacuated, vented and ignition sources removed, depending onconditions, either due to the presence of natural gas or as a precaution. It is notuncommon for gas to migrate into several exposures. Gas can travel far beneath thesurface and enter some buildings while bypassing others.

In addition to preliminary and progress reports, the IC should relay any criticalinformation to the dispatcher. In addition, prior to the arrival of the Utility Company onscene, the IC may contact the Utility Company’s Control Center via cell phone.

o Con Edison Gas: Gas Emergency Desk (718-319-2330)

o National Grid: Lead Gas Controller (631-861-2901)

10.1 CHIEF OFFICER POSITIONS

1. First arriving BC – Incident Commander

2. Second arriving BC – As determined by the Incident Commander

The second arriving BC should be assigned as needed. This chief may be assigned tosupervise a difficult area or task, allowing the IC to focus on strategy and evaluate theoverall operation. Most of the work required at Major Gas Emergencies should beaccomplished by task forces or strike teams whose formation and assignment areestablished by the IC with subject matter expert input. This chief may be positionedwhere concern is greatest or coordination between groups and teams is essential.

3. Haz-Mat Battalion

The Haz-Mat Battalion may be utilized to assist in planning of strategy as well asfunction as a liaison with Utility Companies. The Haz-Mat Battalion may work closelywith other agencies to address technical issues and problems and some considerations thischief should address with Utility Companies include:

o Strategy and tactics; with estimated time frames, reconnaissance pertaining to piperuns/types, valve locations/types, sewer runs, etc.

o Compare meter reading levels and locations to re-evaluate the condition, boundariesof the leak and potential blast zone.

4. Safety Battalion

Upon arrival of the Safety Battalion, the IC should use this chief to assist in defining thepotential blast zone and keep all members who are not involved in direct life-savingoperations out. This should continue throughout the operation as boundaries can easilychange. Continuous monitoring should take place outside of the potential blast zone toensure gas does not migrate unexpectedly and adversely change the situation.


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The Safety Battalion should contact members to acquire gas meter readings/locations toassist in defining the extent of the potential blast zone. As mitigation progresses, theexclusion zone should get smaller. The Safety Battalion should advise the IC as to theextent of the potential blast zone, while making sure it is properly marked off and that allunits and the dispatcher are notified as to the extent of the area. The Safety Battalionshould remain at this assignment throughout the operation.

5. Staging Area Manager

The officer at the Staging Area will be the Staging Area Manager until relieved by anassigned Chief Officer designated the Staging Area Manager.

The establishment of a Staging Area is necessary to aid in command and control due tothe risks and the potential of an extensive operational area.

11. ADDITIONAL RESOURCES

1. Special Units

Resources such as the Haz-Mat Battalion, Rescue Battalion, Haz-Mat Company 1,Haz-Mat Technician Units and Rescue Companies should be used to the fullest extentwhen necessary. These units will inform the IC as to how they can best be used at theseemergencies. As they report in, apprise special units of conditions, objectives andstrategies.

2. Utility Companies

Con Edison Gas, Con Edison Electric, National Grid, and PSEGLI (Rockaways, electricservice) will dispatch crews based on the number and nature of calls, availability of crewsand the type of work crews are already dedicated to.

Early contact through the dispatcher, and directly with the Utility Company using plainspeak, will facilitate a coordinated response at these emergencies.

The IC should notify the dispatcher of any information critical to the ongoing operation.In addition, prior to the arrival of the Utility Company on scene, direct contact with theUtility Company is available to the IC via cell phone. Chiefs may call the UtilityCompany directly:

o Con Edison Gas’ “Gas Emergency Desk”: (718-319-2330)

o National Grid’s “Lead Gas Controller”: (631-861-2901)

o Con Edison Electric:

Manhattan: (212-780-3747)

Bronx: (914-925-6199)

Staten Island: (718-390-6490)

Brooklyn/Queens: (718-855-8675)

o PSEGLI (Rockaway’s Electric Service): (631-755-6400)


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*Phone numbers should be entered into Battalion and Division cellular phones or may beobtained from the dispatcher or NYCEM.

Both Con Edison Gas and National Grid use two types of single resource crews; one iscapable of assessing and working on natural gas pipe above ground, and one is in chargeof natural gas pipe below ground.

o Con Edison Gas’ above-ground branch crews are called “Gas Distribution Services”or “GDS” crews. Below-ground branch crews for Con Edison Gas are called“Gas Construction” crews.

o National Grid’s above-ground branch crews are called “Customer Meter Service”crews. National Grid’s below-ground branch crews are called “Gas Field Operations”crews.

Calling either Utility Company for a “construction crew” should be sufficient to get acrew capable of working on pipe below-ground.

It is important to specify the need for a construction crew if the operation mayrequire work below ground. If a curb valve/service valve fails on a low pressuresystem, a construction crew will be required.

Utility Company construction crews typically take longer to respond than other UtilityCompany personnel. There are less of them and they are often already engaged inexcavation and/or large scale repair/installation work.

The IC’s use of street management will facilitate getting the Utility Company’sequipment and personnel to the point of operation.

Task forces will likely consist of mixed crews of FDNY members with one member fromthe Utility Company, to perform reconnaissance, evacuation and venting, as well aslocating valves, pulling manhole covers, etc.

Utility Company crews are managed and coordinated by supervisors who in turn report totheir control centers to update conditions, request resources and retrieve technical data onpipe runs, valve types and locations.

Similar to the FDNY, Utility Companies will assign more resources and build an IncidentCommand System based on their understanding of the incident and potential for harmand disruption of service. The first supervisor on the scene will be involved indetermining the scope of the emergency, directing resources and reporting to the controlcenter. It is likely the initial Utility Company supervisor will be moving about theincident as he/she tries to evaluate conditions and supervise workers; this createsdifficulty in establishing contact early on. Any unit observing the arrival of the first-on-scene Utility Company crew or supervisor should report the arrival to the IC and informthe Utility Company member to report to the FDNY IC.


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3. New York City Emergency Management

Activate and coordinate resources from various agencies and parties. New York CityEmergency Management (NYCEM) personnel can often identify which person or agency(with the proper authority) to contact. In addition, NYCEM can facilitate the following:

o Request rapid NYPD response to assist in pedestrian and vehicle traffic control.

o Retrieve information as to the run of underground infrastructure, specifically waterand sewer lines which Gas Utility Companies will not have mapped.

o Assist with the management of long-term operations such as disruption of streetaccess, relocations of occupants, etc.

NYCEM may be contacted through the dispatcher and by calling NYCEM WatchCommand at 718-422-8700.

4. New York City Police Department

The NYPD can assist in evacuation.

The NYPD can manage the scene by controlling vehicle and pedestrian traffic.

In addition, the NYPD can request a tow or search the registration record of parkedvehicles to expedite the removal of such vehicles and create access for Utility Companycrews.


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Major Gas Emergency Checklist

o 1st Arriving Chief Officer Determine Explosion Profile based on Size-up, Meter Readings and Location When necessary, designate Potential Blast Zone - DANGER DO NOT ENTER TAPE Announce boundaries of PBZ over HT and Dept. Radio Establish Incident Command Post outside of PBZ Restrict operations in the PBZ to direct life-saving only Announce location of Staging Area

o Size Up/Initial Operations Initial Bldg. Involved/ Leak IFO: Address ______________ Occupancy ___________

CL ______ Ht ________ Dim _______x_______ Floor/Area _________________ Extent of Gas Leak Location of Leak Known _____ Unknown _____ High/Medium or Low Pressure Service _______ Readings Taken: ______ Evacuation

Units Area/Address/ Floor Underway / Complete (times) _________ __________________ _________ _________ _________ __________________ _________ _________ _________ __________________ _________ _________ _________ __________________ _________ _________

o Operations Inside Potential Blast Zone PBZ Designated/ Marked______ Announced HT_____ Dept. Radio _______ Safety Officer Assigned_______ Bn_____

Units Area/Address/ Floor Underway/ / Complete (times) _________ __________________ _________ _________ _________ __________________ _________ _________

o Preliminary/ Progress Reports Preliminary Report Transmit a 10-75 and 10-80 Code 1, specifying a “Major Gas Emergency” ________ Indicate Conditions/Actions/Needs _______ Location of Command Post and Staging Area _______

Progress Reports Evacuation underway/ complete _______ Gas meter readings/ locations _________ Venting/ mitigation _________ Units ________


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o Street Management Plan Control Vehicle Access __________ Control Pedestrian Access __________ Contact NYCEM/law enforcement for Assistance __________

o Resource Response TL _______________ FAST _______________ CFR _______________ Safety Battalion _______ Staging Area _________ Rescue Battalion ______ Rescues ______________ HMC1 _______________ HMTU _______________ SSL's _______________ Medical Branch _______

o Additional Resources Con Ed Gas ____________________ Nat Grid ____________________ Con Ed Electric ___________________ PSEG (Rockaway Electric) ________ OEM __________ NYPD __________ Transit __________ Other __________

ep natural gas - firetesttaking

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