1. Utility Emergencies Second Edition Issued: February 2008
Revised: April 2014

2. Purpose of the Utility Emergencies Manual:
Identify the various utility hazards associated with firefighting & emergency response
Identify safety measures firefighters should take at incidents involving malfunctioning utilities
Describe the types of utility emergencies
Describe utility control devices
Establish appropriate tactics and resources
Identify the method to locate utility hazards
2nd Addition-April 2014

3. Utility services outlined in this manual:
Natural Gas
Propane
Carbon Monoxide
Electrical Power
Water Emergencies
2nd Addition-April 2014

4. Natural Gas (Methane)
Methane is a simple hydrocarbon consisting of carbon and hydrogen.
Vapor density is the weight of a given volume of gas compared to the weight of the same amount of air at the same temperature and pressure.
Methane has a vapor density of .55, therefore it will rise.
2nd Addition-April 2014

5. Natural Gas Colorless and odorless (In its pure state)
Mercaptan is an added odor as a safety precaution
Natural gas in transmission pipelines & rail cars is not odorized
LEL is 5% and UEL is 15%
Ignition temperature is 1200° Fahrenheit
Transmission lines range from 6” to 30” w/ pressures up to 450psi
Lines can generate 2,000 to 4,000 volts of static electricity
2nd Addition-April 2014

6. Natural Gas
Pipeline companies are ultimately responsible for the safety and reliability of their own pipeline systems.
The following events may indicate a pipeline leak;
Hissing or roaring sound
Unusual odor near the pipeline
Dead or discolored vegetation in an otherwise green location
Fire coming from the ground or appearing to burn above the ground
Dirt being blown or appearing to be thrown into the air
Water bubbling or being blown into the air at a pond, creek, or river
Dry spot in a moist field
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7. Natural Gas
Firefighters should note the following concerning marking systems:
Markers show the pipeline’s approximate location
Signs on the markers list the commodity transported, the name of the pipeline company, and a telephone number for company reps
Markers do not indicate how deep the pipeline is buried or how many lines are in the area
Pipelines do not necessarily follow a straight line between two markers
2nd Addition-April 2014

8. Natural Gas Response Ensure utility company is enroute
Companies should position prior to and upwind
Identify an adequate water supply source
Do not position over sewers, valve covers, or manhole covers
General Rule:
No closer than 100’ for 1st Arriving Unit
Minimum of 300’ distance for all other fire apparatus
*Always move apparatus if any odor detected
2nd Addition-April 2014

9. Outside Natural Gas Leaks
Ensure utility company is enroute to active gas leaks
Do not attempt to handle any plastic or steel pipe at the leak site
Static electricity can be up to 24,000 volts
If necessary to come in contact with a leaking gas line, an approved grounding device should be used
It is recommended that no firefighters crimp or clamp a leaking line unless an extreme life-saving situation
Do not cover any pipe that is leaking
2nd Addition-April 2014

10. Outside Natural Gas Leaks
A firefighter should be positioned upwind w/ a 20lb dry chemical extinguisher and a charged hoseline, if needed
May be best to control the leak by closing a curb valve or gas meter
DO NOT ever operate any street valves
If a gas valve is turned off, do not turn it back on as this may cause an explosion
Street Valve
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11. Outside Natural Gas Fires
A minimum of an 1¾” with a dry chemical extinguisher should be deployed
A burning gas is not explosive, but if the fire is extinguished without shutting off the gas an explosive condition has been created
Allow the gas to burn while protecting surrounding combustibles
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12. Inside Natural Gas Leaks
Evacuate the structure
Control ignition sources
Locate and control leak
Control the leak by shutting off the valve prior to the meter.
DO NOT operate any street valves
Naturally ventilate when possible
Outside Meter
Inside Meter
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13. Inside Natural Gas Fires
Ensure utility company is enroute
Normal firefighting operations except extinguishing the gas fire
Wet down surrounding combustibles while gas is shut-off
Unburned gas accumulating will quickly reach an explosive range
2nd Addition-April 2014

14. Shut Off for Natural Gas
Gas shut off valves are quarter-turn. The proper sequence for shutting off the utility in either leak or fire situation is as follows:
At the appliance (if can be safely done)
At the meter
At the curb box
2nd Addition-April 2014

15. Propane
Propane is a fossil fuel found mixed with natural gas and petroleum deposits in rocks underground
Vapor density of 1.56 making it heavier than air
LEL of 2.3 and UEL of 9.5
Ignition temperature between 920° and 1200° Fahrenheit
Colorless and odorless w/ ethyl mercaptan added for leak detection
2nd Addition-April 2014

16. Propane Response Ensure utility company is enroute
Companies should position prior to and upwind
Identify an adequate water supply source
Do not position over sewers, valve covers, or manhole covers
2nd Addition-April 2014

17. Propane Check surrounding manholes, basements, and underground vaults
Recommended to have two 1¾ hoselines w/ narrow fog patterns for vapor suppression
Most common incidents involved 20lb cylinders
Every container will have at least one relief valve
Do not stop the vapor release, if valve is operating properly
Propane cylinders need a 20% air space to accommodate ambient temperature changes
2nd Addition-April 2014

18. Outside Propane Tank Fire or Exposure
Venting tank with burning product-cool the tank at the vapor space
Recommended to have 1¾ hoseline; Do not direct water at source of leak or safety devices—icing may occur
Relief valve sets—Protected crews can close off tank
Fighting a fire and hear a rising sound from venting devices or see discoloration of the tank—Leave the area immediately
Never stand / walk in path of the relief valve
2nd Addition-April 2014

19. Inside Propane Leaks Handle leaks similar to inside natural gas leaks
Major Exception:
LPG is heavier than air and will seek lower areas
Best practice to secure the gas at the tank from the outside of the structure.
2nd Addition-April 2014

20. Carbon Monoxide
Carbon Monoxide is formed by the incomplete combustion of the fossil fuels
LEL is 12.8% and UEL is 74%
Colorless and odorless
Symptoms of exposure are headache, nausea, fatigue, confusion, and dizziness – patients should be transported to a hyperbaric chamber when appropriate
35ppm over an 8 hour period or 50ppm over one hour is the max for acceptable levels of CO per OSHA in the general workplace
2nd Addition-April 2014

21. Carbon Monoxide Exposure Limits
OSHA Standards for CO Exposure
PPM's
Effects
Time Elapsed 35
No effect
8 hours
200
Minimal effect
15 minutes
Slight headache, fatigue, nausea
2-3 hours
400
Life threatening frontal headache
3 hours
800
Dizzy, nausea, convulsions, unconscious
45 minutes
Death
12,800
1-3 minutes
2nd Addition-April 2014

22. Absolute Limit of Approach
Electrical Power
Minimum PPE should include full turnout gear
Request utility company to assist with significant and unique electrical situations and when their expertise is required
Safest insulator for electricity is distance
There is an absolute line of approach to
power lines:
Minimum limit of approach by line voltage
Line Voltage
Absolute Limit of Approach
Up to 50,000
10 feet
50,000 to 115,000
12 feet
115,000 to 230,000
16 feet
230,000 to 500,000
25 feet
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23. Electrical Power
Isolate electrical power at equipment, circuit breakers or fuse box before taking direct action
When isolation of power is not possible, isolate area, call for needed resources, protect exposures, maintain safe distance, and await power company
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24. Electrical Power
Keep conductive tools and equipment clear of electrical equipment
Do not enter substations, electrical vaults, or pad mounted transformers without the utility representative
When water application is necessary near or on electrical equipment, isolate power first when possible and use a wide to narrow fog pattern
Consider using a Class C extinguisher where applicable
2nd Addition-April 2014

25. Electrical Power Volts Amps Ohms
The unit of electromotive force, the volt measures how much pressure there is in an electric circuit (pressure)
Can kill!
Amps
A unit of electric current. One ampere corresponds to a certain number of electrons passing a fixed point each second (GPM).
Will kill!
Ohms
Unit of electrical resistance (friction)
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26. Conductors vs. Insulators
Conductors allows the flow of electricity-low resistance that completes the path of a circuit
Insulators blocks the flow of electricity-high resistance.
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27. Electric Distribution System
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28. Electric Transmission Line
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29. Single Phase Transformer
Electric Distribution Elements
Single Phase Transformer
Primary Lines
Secondary Lines
Communication Lines
Cable TV / Telephone
Insulators
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30. Transformers Pole Mounted Transformer
Common for overhead electrical line service and offer various application
Used to step down voltage
Can be 1 or 3-phase
Single phase normally provides 120/240 volts
3-phase normally provides 240 volts and higher
2nd Addition-April 2014

31. Transformers Pad Mounted Transformer
For underground service applications
Used to step down voltage
Can be 1 or 3-phase
Located at grade or in underground vaults
Common service applications include residential, commercial, hospitals, schools, etc
Come in various sizes
2nd Addition-April 2014

32. Electrical Emergency Responses
Pole fires – water should not be used unless de-energized. Dry chem or CO2 extinguished may be used.
Ground transformers – doors should not be open unless power has been controlled. May use dry chem or CO2 extinguisher.
Underground vaults, manholes, or substations
Never enter, Ensure electric company is enroute, Stay clear of manhole covers, & Monitor surrounding buildings for CO
2nd Addition-April 2014

33. Interstitial Spaces
An intermediate space located between regular-use floors, commonly located in hospitals and laboratory-typ buildings to allow space for mechanical systems
Firefighters should be aware of these unique spaces and the hazards in these spaces within their first due
SCBA shall be worn when investigating any emergency within these spaces.
2nd Addition-April 2014

34. Structure Fires Water Emergencies
Electric panel is the safest place to lock out power
Main disconnects on the exterior may be necessary if electric can not be isolated inside of a building
Electric meter is only a measuring device
Certified electric company representative pull meters
Water Emergencies
Assess the impact of water emergency on electrical systems; Notify utility companies; Secure utilities from safe location
2nd Addition-April 2014