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Title: Hazard Assessment And Risk Evaluation


1
Hazard Assessment And Risk Evaluation
Textbook Page
2
Objectives
  • Describe The Concept Of Hazard Assessment And
    Risk Evaluation.
  • Describe The Following Terms And Explain Their
    Significance In The Risk Assessment Process NFPA
    472 - 6.2.2(b).
  • Describe The Heat Transfer Processes That Occur
    As A Result Of A Cryogenic Liquid Spill NFPA 472
    -6.2.2(c).

3
Objectives
  • Identify And Interpret The Types Of Hazard And
    Response Information Available From Each Of The
    Following Resources, And Explain The Advantages
    And Disadvantages Of Each Resource NFPA 472
    -6.2.2(a).
  • Hazardous Materials Databases
  • Maps And Diagrams
  • Monitoring Equipment
  • Reference Manuals
  • Technical Information Centers
  • Technical Information Specialists

4
Objectives
  • Identify The Steps In An Analysis Process For
    Identifying Unknown Solid And Liquid Materials
    NFPA 472-6.2.1.3(a).
  • Identify The Steps In An Analysis Process For
    Identifying An Unknown Atmosphere NFPA
    472-6.2.1.3(b).

5
Objectives
  • Identify The Types Of Monitoring Equipment, Test
    Strips, And Reagents Used To Determine The
    Following Hazards NFPA 472-6.2.1.3(c)
  • Corrosivity
  • Flammability
  • Oxidation Potential
  • Oxygen Deficiency
  • Radioactivitiy
  • Toxic Levels

6
Objectives
  • Identify The Capabilities And Limiting Factors
    Associated With The Selection And Use Of The
    Following Monitoring Equipment, Test Strips, And
    Reagents NFPA 472-6.2.1.3(d)
  • Carbon Monoxide Meter
  • Colorimetric Tubes
  • Combustible Gas Indicator
  • Oxygen Meter
  • Passive Dosimeter
  • Photoionization Detector
  • Ph Indicators And/Or Ph Meters
  • Radiation Detection And Measurement Instruments

7
Objectives
  • Reagants
  • Test Strips
  • Describe The Basic Identification Tools And
    Detection Devices For Each Of The Following NFPA
    472-6.2.1.1(g)
  • Nerve Agents
  • Vesicants (Blister Agents)
  • Biological Agents And Toxins
  • Irritants (Riot Control Agents)
  • Identify Two Methods For Determining The Pressure
    In Bulk Packaging Or Facility Containers NFPA
    472-6.2.2(f).

8
Objectives
  • Identify One Method For Determining The Amount Of
    Lading Remaining In Damaged Bulk Packaging Or
    Facility Containers NFPA 472-6.2.2(g).
  • Identify And Describe The Components Of The
    General Hazardous Materials Behavior Model
    (GEBMO).
  • Identify The Types Of Damage That A Pressure
    Container Could Incur NFPA 472-6.2.3.4.
  • Identify At Least Three Resources Available That
    Indicate The Effects Of Mixing Various Hazardous
    Materials NFPA 472 - 6.2.4.1.

9
Objectives
  • Identify The Steps For Determining The Extent Of
    The Physical, Safety, And Health Hazards Within
    The Endangered Area Of A Hazardous Materials
    Incident NFPA 472-6.2.5.2.
  • Identify Two Methods For Predicting The Areas Of
    Potential Harm Within The Endangered Area Of A
    Hazardous Materials Incident NFPA
    472-6.2.5.2(c).
  • Describe The Steps For Estimating The Outcomes
    Within An Endangered Area At A Hazardous
    Materials Incident NFPA 472-6.2.5.3.

10
Objectives
  • Describe The Steps For Determining Response
    Objectives (Defensive, Offensive, And
    Nonintervention) Given An Analysis Of A Hazardous
    Materials Incident. NFPA 472-6.3.1.2.
  • Identify The Possible Action Options To
    Accomplish A Given Response Objective NFPA 472-
    6.3.2.2.
  • Describe The Factors That Influence The
    Underground Movement Of Hazardous Materials In
    Soil And Through Groundwater.

11
Objectives
  • Identify The Hazards Associated With The Movement
    Of Hazardous Materials In The Following Types Of
    Sewer Collection Systems
  • Storm Sewers
  • Sanitary Sewers
  • Combination Sewers
  • List Five Site Safety Procedures For Handling An
    Emergency Involving A Hydrocarbon Spill Into A
    Sewer Collection System.

12
Introduction
  • The Evaluation Of Hazard Information And The
    Assessment Of Risks Is The Most Critical
    Decision-making Point In The Successful
    Management Of A Hazardous Materials Incident.
  • The Chapter Is Based On The Premise That
    Responders Have
  • Successfully Implemented Site Management
    Procedures
  • Identified The Nature Of The Problem And The
    Materials Potentially Involved.

13
Introduction
  • Topics Include
  • Understanding Hazardous Materials Behavior
  • Outlining The Common Sources Of Hazard
    Information
  • Evaluating Risks
  • Determining Response Objectives

14
Basic Principles
  • The Concept Of Hazard And Risk Evaluation Is
    Recognized As A Critical Benchmark In Safe And
    Successful Emergency Response Operations
  • If We Review Incidents And Case Studies Where
    Emergency Responders Have Been Injured Or Killed,
    In Most Instances It Is Not Due To Their Failure
    To Assess And Understand The Hazard
  • In Contrast, One Of The Most Common Root Causes
    Is Our Failure To Adequately Evaluate And
    Understand The Level Of Risk Involved

15
What Are Hazards And Risks?
  • Hazards Refer To A Danger Or Peril. In Hazardous
    Materials Response Operations, Hazards Generally
    Refer To The Physical And Chemical Properties Of
    A Material.
  • Risks Refer To The Probability Of Suffering Harm
    Or Loss. Risks Cant Be Determined From Books Or
    Pulled From Computerized Data Bases They Are
    Those Intangibles That Are Different At Every
    Hazmat Incident And Must Be Evaluated By A
    Knowledgeable Incident Commander.

16
What Are Hazards And Risks?
  • Risk Levels Are Variable And Change From Incident
    To Incident. Factors That Influence The Level Of
    Risk Include The Following
  • Hazardous Nature Of The Material(s) Involved.
  • Quantity Of The Material Involved.
  • Containment System And Type Of Stress Applied To
    The Container.
  • Proximity Of Exposures.
  • Level Of Available Resources.

17
What Are Hazards And Risks?
  • In This Chapter, The Hazard And Risk Evaluation
    Process Will Be Viewed As Three Distinct Yet
    Inter-related Tasks
  • Hazard Assessment
  • Risk Evaluation
  • Development Of The IAP

18
Physical And Chemical Properties
  • To Evaluate Risks Effectively, Responders Must Be
    Able To Identify And Verify The Materials
    Involved, And Determine Their Hazards And
    Behavior Characteristics.
  • To Mount A Safe And Effective Hazmat Response,
    Responders Must Understand
  • How The Enemy Will Behave (I.E., Its Physical
    Properties)
  • How It Can Harm (I.E., Its Chemical Properties).
  • In This Section We Review The Key Physical And
    Chemical Properties Of Hazardous Materials And
    Their Role In The Risk Assessment Process.

19
General Chemical Terms And Definitions
  • The Following Terms Are Commonly Found On a MSDS
    And In Various Emergency Response References As
    Part Of A Materials Description Or Basic
    Chemical Make-up.
  • Element
  • Compound
  • Mixture
  • Solution
  • Slurry
  • Cryogenic Liquid

20
General Chemical Terms And Definitions
  • Ionic Bonding
  • Covalent Bonding
  • Organic Materials
  • Inorganic Materials
  • Hydrocarbons
  • Saturated Hydrocarbons
  • Unsaturated Hydrocarbons
  • Aromatic Hydrocarbons
  • Halogenated Hydrocarbons

21
Physical Properties
  • Physical Properties Provide Information On The
    Behavior Of A Material.
  • Normal Physical State
  • Temperature Of Product
  • Specific Gravity
  • Vapor Density
  • Boiling Point
  • Melting Point
  • Sublimation
  • Critical Temperature And Pressure

22
Physical Properties
  • Volatility
  • Evaporation Rate
  • Expansion Ratio
  • Vapor Pressure
  • Solubility
  • Miscibility
  • Degree Of Solubility
  • Viscosity

23
Chemical Properties
  • Chemical Properties Are The Intrinsic
    Characteristics Or Properties Of A Substance
    Described By Its Tendency To Undergo Chemical
    Change.
  • In Simple Terms, The True Identity Of The
    Material Is Changed As A Result Of A Chemical
    Reaction Such As Reactivity And The Heat Of
    Combustion.
  • Chemical Properties Typically Provide Responders
    With An Understanding Of How A Material May Harm.

24
Flammability Hazards
  • Flash Point
  • Fire Point
  • Ignition (Auto-ignition) Temperature
  • Flammable (Explosive) Range
  • Toxic Products Of Combustion

25
Reactivity Hazards
  • Reactivity/Instability
  • Oxidation Ability
  • Water Reactivity
  • Air Reactivity (Pyrophoric Materials)
  • Chemical Reactivity
  • Polymerization

26
Reactivity Hazards
  • Catalyst
  • Inhibitor
  • Maximum Safe Storage Temperature (MSST)
  • Self-accelerating Decomposition Temperature (SADT)

27
Corrosivity Hazards
  • Corrosivity
  • Acids
  • Caustics
  • Ph
  • Strength
  • Concentration

28
Radioactive Materials
  • Radioactivity
  • Activity
  • Dose
  • Dose Rate
  • Half-life

29
Chemical And Biological Agents/Weapons
  • Biological Agents And Toxins
  • Chemical Agents
  • Nerve Agents
  • Choking Agents
  • Blood Agents
  • Vesicants (Blister Agents)
  • Riot Control Agents
  • Persistence

30
Sources Of Hazard Data And Information
  • Two Primary Tasks Within The Hazard And Risk
    Evaluation Process Are
  • To Gather Hazard Data And Information On The
    Materials Involved
  • To Compile That Data In A Useful Manner So That
    The Risk Evaluation Process Can Be Accomplished
    In A Timely And Efficient Manner.

31
Sources Of Hazard Data And Information
  • Hazard Data And Information Sources Can Be Broken
    Into The Following Categories
  • Reference Manuals And Guidebooks
  • Technical Information Centers
  • Hazardous Materials Databases
  • Technical Information Specialists
  • Hazard Communication And Right-to-know
    Regulations
  • Monitoring Instruments

32
Reference Manuals And Guidebooks
  • A Wide Variety Of Emergency Response Guidebooks
    And Reference Manuals Exist. These Range From
    Small Field Operations Guides (Or Fogs) That Can
    Fit Into Your Pocket To Multi-volume Reference
    Manuals
  • Despite The Large Number Of Written Resources
    Available, Most Responders Initially Rely On
    Three To Five Primary Response Guidebooks For
    Most Of Their Data And Information.

33
Reference Manuals And Guidebooks
  • As With All Resources, Guidebooks Are An
    Information Tool With Both Advantages And
    Limitations. Several Operational Considerations
    Should Be Kept In Mind When Using Them
  • You Must Know How To Use Emergency Response
    Guidebooks Before The Incident In Order To Use
    Them Effectively.
  • Most Responders Will Evaluate A Minimum Of Two Or
    Three Independent Information Sources And
    Reference Guidebooks Before Permitting Personnel
    To Operate Within The Hot Zone.

34
Reference Manuals And Guidebooks
  • In Some Instances, There May Be Conflicting
    Information Between Guidebooks.
  • Be Realistic In Your Evaluation Of The Data
    Contained In The Guidebooks.
  • Always Rely On The Protective Clothing
    Compatibility Charts Provided By The Clothing
    Manufacturer.
  • Although Reference Guidebooks Contain Data On
    Those Chemicals Most Commonly Encountered During
    Hazmat Incidents, They Are Not A Complete Listing
    Of The Chemicals Found In Your Community.
  • Electronic Versions Of Most Of The Major
    Emergency Response Guidebooks Are Also Available.

35
Technical Information Centers
  • A Number Of Private And Public Sector Hazardous
    Materials Emergency Hotlines Exist.
  • Their Functions Include
  • Providing Immediate Chemical Hazard Information
  • Accessing Secondary Forms Of Expertise For
    Additional Action And Information
  • Acting As A Clearinghouse For Spill
    Notifications. They Include Both Public And
    Subscription-based Systems

36
Technical Information Centers
  • CHEMTREC (Chemical Transportation Emergency
    Center).
  • Operated By The American Chemistry Council (ACC)
    In Arlington, Virginia
  • CHEMTREC Is A Free Public Service That Can Be
    Contacted 24 Hours Daily At (800) 424-9300 From
    Anywhere Within The United States, As Well As
    Puerto Rico, The Virgin Islands, And Canada.

37
Technical Information Centers
  • The CHEMTREC Center Provides A Number Of
    Emergency And Non-emergency Services, Including
    The Following
  • Emergency Response Information.
  • Emergency Communications.
  • Chemical Industry Mutual Aid Network.
  • Participation In Drills And Exercises.

38
Other Technical Information Numbers
  • CANUTEC (Canadian Transport Emergency Centre) Is
    Operated By Transport Canada And Can Be Contacted
    At (613) 996-6666. The General Information Number
    Is (613) 992-4624.
  • SETIQ (Emergency Transportation System For The
    Chemical Industry) Is A Service Of The Mexico
    National Association Of Chemical Industries And
    Can Be Contacted At 01-800-00-214-00 In The
    Mexican Republic.

39
Technical Information Centers
  • U.S. Coast Guard And The Department Of
    Transportation National Response Center (NRC) At
    (800) 424-8802, Or At (202) 267-2675 For Those
    Without 800 Access.
  • The NRC (National Response Center)
  • The Agency For Toxic Substances And Disease
    Registry (ATSDR) At (404) 498-0120.
  • National Animal Poison Control Center (NAPCC) At
    (900) 680-0000 Or (800) 548-2423.
  • National Pesticide Information Center (NPIC) At
    (800) 858-7378.

40
Hazardous Materials Web Sites And Computer
Databases
  • Portable Computers, Personal Desk Assistants
    (PDAs), Smart Phones, CD-Roms, And Internet
    Access Have Literally Revolutionized The Ability
    Of Emergency Responders To Search And Access
    Hazard Information From The Field.
  • Examples Of Some Computer-based And Electronic
    Tools Include
  • CAMEO (Computer Assisted Management Of Emergency
    Operations) Is The Most Widely Used
    Computer-based Software Tool Used By Hazmat
    Responders.

289
41
Hazardous Materials Web Sites And Computer
Databases
  • The CAMEO Database
  • MARPLOT (Mapping Applications For Response,
    Planning, And Local Operational Tasks)
  • ALOHA (Aerial Locations Of Hazardous
    Atmospheres) 
  • The CHEMTREC And EPA Chemical Emergency
    Preparedness And Prevention Office (CEPPO)
  • The NOAA Chemical Reactivity Worksheet Is An
    Excellent Tool That Can Be Downloaded And Used
    For Determining The Effects Of Various Chemical
    Mixtures.
  • The Operation Respond Institutes OREIS?
  • DOT, OSHA, EPA, NRC

42
Hazardous Materials Web Sites And Computer
Databases
  • When Evaluating Electronic-based Information
    Sources, Consider The Following Criteria
  • How Will The Tool Complement Or Improve Your
    Response Operations And Decision Making?
  • Costs, Including Initial Subscription And User
    Fees.
  • Hardware And Software Requirements, Including
    Communications Technology.
  • Communications Security (COMSEC), As Appropriate.
  • Ease Of Use And User Friendliness.
  • Technical Support

43
Technical Information Specialists
  • A Common Source Of Hazard Information Are
    Personnel Who Either Work With The Hazardous
    Material(s) Or Their Processing, Or Who Have Some
    Specialized Knowledge, Such As Container Design,
    Toxicology, Or Chemistry. When Evaluating These
    Product And Container Specialists And The
    Information They Provide, Consider These
    Observations And Lessons Learned
  • Many Individuals Who Are Specialists In A Narrow,
    Specific Technical Area May Not Have An
    Understanding Of The Broad, Multi-disciplined
    Nature Of Hazmat Emergency Response.

44
Technical Information Specialists
  • Each Information Specialist Has Their Own
    Strengths And Limitations.
  • You Will Often Interact With Individuals With
    Whom You Have Had No Previous Contact.
  • When Questioning Outside Information Sources,
    Consider Yourself As Playing The Role Of A
    Detective.
  • Local Responders And Facility Personnel Must Get
    Out Into Their Communities And Establish Personal
    Contacts And Relationships With Your Response
    Partners.
  • Investigate The Existence Of Local And State
    Good Samaritan Legislation That May Cover
    Outside Representatives As They Assist You On The
    Scene.

45
Hazard Communication And Right-to-know Regulations
  • Numerous State And Local Worker And Community
    Right-to-know Laws Exist Across The Country.
  • While The Scope Of These Regulations May Vary,
    Most Right-to-know Laws Provide Emergency
    Responders With Access To MSDS And Have Specific
    Requirements Mandating The Development Of
    Facility Pre-incident Plans And Community
    Hazardous Materials

46
Hazard Communication And Right-to-know Regulations
  • OSHA Requires That Certain Basic Data And
    Information Be Provided On Each MSDS, Including
    The Following
  • General Information
  • Hazardous Ingredient Statement
  • Physical Data
  • Fire And Explosion Data
  • Health And Reactivity Hazard Data (As Necessary)

47
Hazard Communication And Right-to-know Regulations
  • Spill And Leak Control Procedures
  • Special Protection Information
  • Other Special Precautions (As Necessary).
  • Msdss Have No Uniform Or Consistent Format Or
    Layout.
  • Computer-generated Msdss May Be Difficult To
    Initially Use And Interpret Because Of Their
    Layout.
  • There Are No Regulatory Requirements Concerning
    The Language And Terminology Used.

48
Monitoring Instruments
  • Monitoring And Detection Equipment Are Critical
    Tools For Evaluating Real-time Incident Data To
  • Determine If Anything Is Present.
  • Classify Or Identify Unknown Hazards.
  • Determine The Appropriate Levels Of Personal
    Protective Clothing And Equipment.
  • Determine The Size And Location Of Hazard Zones.
  • Develop Protective Action Recommendations
  • Assess The Potential Health Effects Of Exposure.
  • Determine When The Incident Scene Is Safe So That
    The Public And/Or Facility Personnel May Be
    Allowed To Return.

49
Monitoring Instruments
  • Monitoring Is An Integral Part Of Site Safety
    Operations And A Cornerstone Of A Risk-based
    Emergency Response Philosophy.
  • Hazardous Materials Concentrations Can Be
    Identified, Quantified, And/Or Verified In Two
    Ways
  • On-site Use Of Direct-reading Instruments, Which
    Provide Readings At The Same Time That Monitoring
    Is Being Performed
  • Laboratory Analysis Of Samples Obtained Through
    Several Collection Methods. Both Tools Are
    Discussed In This Section.

50
Selecting Direct-reading Instruments
  • Direct-reading Instruments Provide Information At
    The Time Of Sampling, Thereby Allowing For Rapid,
    On-scene Risk Evaluation And Decision Making.
  • When Evaluating Survey Instruments For Emergency
    Response Use In The Field, Consider The Following
    Criteria
  • Portability And User Friendliness
  • Instrument Response Time
  • Sensitivity And Selectivity
  • Lower Detection Limit (LDL)

51
Selecting Direct-reading Instruments
  • Calibration
  • There Are Four Types Of Calibration
  • Factory Calibration
  • Full Calibration
  • Field Calibration
  • Bump Test
  • Correction Factors (I.E., Relative Response
    Curves)
  • Inherent Safety
  • In Addition To The Previous Criteria, The
    Following Operational, Storage, And Use
    Considerations Should Be Evaluated
  • Where And In What Type Of Storage Container Will
    The Instruments Be Stored?

52
Selecting Direct-reading Instruments
  • Can Field Maintenance Be Easily Performed? For
    Example, Are Field Calibration Kits Available And
    Can Sensors Be Easily Changed In The Field?
  • Can Buttons, Switches, And So On Be Easily
    Manipulated While Wearing Chemical Gloves?
  • How Long Does It Take For The Monitoring
    Instruments To Warm Up Before They Can Be Used
    In The Field?
  • What Types Of Alarms Does The Instrument Have? Is
    There A Glare Problem During Daytime Operations
    And A Lighting Problem For Operations At Night?
  • What Types Of Batteries Are Required For The
    Instrumentoff-the-shelf Batteries Or
    Rechargeable Batteries? How Long Will The Unit
    Operate With A Full Charge?

53
Types Of Direct-reading Instruments
  • All Direct-reading Instruments Have Inherent
    Limitations
  • Many Detect And/Or Measure Only Specific Classes
    Of Chemicals
  • As A General Rule, They Are Not Designed To
    Measure And/Or Detect Airborne Concentrations
    Below 1 ppm
  • Many Direct-reading Instruments Designed To
    Detect One Particular Substance May Detect Other
    Substances (Interference) And Give False Readings

54
Types Of Direct-reading Instruments
  • When Using Direct-reading Instruments, Interpret
    Instrument Readings Conservatively And Consider
    The Following Guidelines
  • Conduct A Daily Check Of Your Instruments, As
    Well As Before Use.
  • Use Chemical Correction Factors When Dealing With
    Known Materials, As Appropriate.
  • Remember That Instrument Readings Have Some
    Limitations When Dealing With Unknown Substances.

55
Types Of Direct-reading Instruments
  • A Reading Of Zero Should Be Reported As No
    Instrument Response Rather Than Clean, Since
    Quantities Of Chemicals May Be Present That
    Cannot Be Detected By That Particular Instrument
    Technology.
  • Remember The Rule Of Threes When Dealing With
    Unknowns And Suspected Criminal Scenarios
    Involving Hazardous Materials Use Several Types
    Of Detection Technologies To Classify Or Identify
    The Hazard.
  • After The Initial Survey, Continue Frequent
    Monitoring Throughout The Incident.

56
Corrosive Monitors
  • APPLICATION
  • METHODS OF OPERATION
  • GENERAL COMMENTS

57
Radiation Survey Monitors
  • APPLICATION
  • METHODS OF OPERATION
  • GENERAL COMMENTS

58
Oxygen Monitors
  • APPLICATION
  • METHODS OF OPERATION
  • GENERAL COMMENTS

59
Combustible Gas Indicators (LEL Meters)
  • APPLICATION
  • METHODS OF OPERATION
  • GENERAL COMMENTS

60
Colorimetric Indicator Tubes (Detector Tubes)
  • APPLICATION
  • METHODS OF OPERATION
  • GENERAL COMMENTS

61
Toxic Gas Sensors
  • APPLICATION
  • METHODS OF OPERATION
  • GENERAL COMMENTS

62
Photo-Ionization Detectors (PID)
  • APPLICATION
  • METHODS OF OPERATION
  • GENERAL COMMENTS

63
Flame Ionization Detectors (PID)
  • APPLICATION
  • METHODS OF OPERATION
  • GENERAL COMMENTS

64
Fourier-Transorm Infared Spectometry (FT-IR)
  • APPLICATION
  • METHODS OF OPERATION
  • GENERAL COMMENTS

65
Miscellaneous Detection Devices
  • APPLICATION
  • METHODS OF OPERATION
  • GENERAL COMMENTS

Haz Cat Kit
Test Strips
Mercury Tester
66
Types Of Direct-reading Instruments
  • Always Remember These Basic Safety
    Considerations
  • Air Monitoring Personnel Have The Greatest Risk
    Of Exposure
  • The Air Monitoring Team Should Consist Of At
    Least Two Personnel, With A Back-up Team Wearing
    An Equal Level Of Protection.
  • Protect The Instruments As Appropriate.
  • Approach The Hazard Area From Upwind Whenever
    Possible.
  • Priority Areas Should Include Confined Spaces,
    Low-lying Areas, And Behind Natural Or Artificial
    Barriers (E.G., Hills, Structures, Etc.), Where
    Heavier- Than- Air Vapors Can Accumulate.

306
67
Monitoring Strategies
  • Establish Monitoring Priorities Based On Whether
    The Incident Is In Open Air Or In An Enclosed Or
    Confined Space Environment.
  • Always Use The Appropriate Monitoring
    Instrument(s) Based On Dealing With Known Or
    Unknown Materials.
  • Monitoring Personnel Should Have A Good Idea Of
    What Readings To Expect.
  • The Absence Of A Positive Response Or Reading
    Does Not Necessarily Mean That Contaminants Are
    Not Present.

68
Monitoring Strategies
  • Never Assume That Only One Hazard Is Present.
  • Remember The Rule Of Threes
  • Interpret The Instrument Readings In More Than
    One Manner (I.E., Always Play Devils Advocate).
  • Establish Action Levels Based On Instrument
    Readings.

69
Monitoring for Terrorism Agents
  • PHOTO-IONIZATION DETECTOR
  • Hazard Monitored
  • General Comments

70
Monitoring for Terrorism Agents
  • ION-MOBILITY SPECTROMERTY (IMS)
  • Hazard Monitored
  • General Comments

71
Monitoring for Terrorism Agents
  • FLAME SPECTRO-PHOTOMERTY
  • Hazard Monitored
  • General Comments

72
Monitoring for Terrorism Agents
  • COLORIMETRIC DETECTOR AND COLOR CHANGE CHEMISTRY
  • Hazard Monitored
  • General Comments

73
Monitoring for Terrorism Agents
  • SURFACE ACOUSTIC WAVE (SAW)
  • Hazard Monitored
  • General Comments

74
Monitoring for Terrorism Agents
  • INFARED SECTROMETRY (FT-IR)
  • Hazard Monitored
  • General Comments

75
Monitoring for Terrorism Agents
  • HAND-HELD IMMUNOASSAYS (HHA)
  • Hazard Monitored
  • General Comments

76
Monitoring for Terrorism Agents
  • POLYMERASE CHAIN REACTION (PCR) TECHNOLOGY
  • Hazard Monitored
  • General Comments

77
Monitoring Results Should Be Documented As
Follows
  • Instrument
  • Location
  • Time
  • Level
  • Reading
  • Monitoring Priorities Will Be Dependent On
    Whether Responders Have Identified The Hazmat(s)
    Involved.

78
Monitoring Results Should Be Documented As
Follows
  • Unknowns Will Create The Greatest Challenge For
    Responders.
  • The Following Monitoring Priority Is Used By Many
    Hazmat Responders When Dealing With Scenarios
    Involving Unknown Substances In An Open-air
    Environments.
  • Radiation
  • Flammability
  • Oxygen
  • Toxicity
  • Indicator Papers, Such As Ph Paper, And M-8 / M-9
    Tape

79
Monitoring Results Should Be Documented As
Follows
  • Toxicity
  • Specific Or Combination Air Monitors, Which
    Detect Toxic Gases Such As Hydrogen Sulfide Or
    Carbon Monoxide.
  • Colorimetric Detector Tubes Can Be Used For Both
    Known And Unknown Substances.
  • Survey Instruments, Such As Flame Ionization
    Detectors (FID) And Photo-ionization Detectors
    (PID).

80
Evaluating Monitoring Results Actions Levels
And Guidelines
  • Initial Air Monitoring Efforts Should Be Directed
    Toward Determining If IDLH Concentrations Are
    Present.
  • Radioactivity Any Positive Reading Twice Above
    Background Levels Or Alpha And/Or Beta Particles
    That Are 200 To 300 Counts Per Minute (CPM) Above
    Background Would Confirm The Existence Of A
    Radiation Hazard And Should Be Used As The Basis
    For Initial Actions.
  • Flammability the IDLH Action Level Is 10 Of The
    Lower Explosive Limit (Lel).
  • Oxygen an IDLH Oxygen-deficient Atmosphere Is
    19.5 Oxygen Or Lower, While An Oxygen-enriched
    Atmosphere Contains 23.5 Oxygen Or Higher.

81
Evaluating Monitoring Results Actions Levels
And Guidelines
  • ToxicityUnless A Published Action Level Or
    Similar Guideline (E.G., ERPG-2) Is Available,
    The STEL Or IDLH Values Should Initially Be Used.
    If There Is No Published IDLH Value, Responders
    May Consider Using An Estimated IDLH Of Ten Times
    The TLV/TWA.
  • Hot Zonemonitoring Readings Above STEL Or IDLH
    Exposure Values.
  • Warm ZoneMonitoring Readings Equal To Or Greater
    Than TLV/TWA Or PEL Exposure Values.
  • Cold ZoneMonitoring Readings Less Than TLV/TWA
    Or PEL Exposure Values.

82
Sampling
  • If Air Monitoring Provides No Information On The
    Identity Or Hazard Class Of The Unknown,
    Responders May Collect A Sample To Conduct Field
    Tests Of The Material
  • Or Send The Sample To A Lab For Further Analysis
  • These Are Usually Solid Or Liquids But Gases Can
    Be Collected

83
Sampling
  • Examples Of Instruments And Systems Used By
    Responders For Analyzing Samples Include The
    Following
  • Locally Developed And Commercial Chemical
    Identification Kits (E.G., Hazcat Chemical
    Identification System).
  • Fourier-transform Infrared Spectrometry (FT-IR).
  • Biological Detection Systems Currently Used In
    The Field Rely On Responders Acquiring A Sample
    And Then Subjecting The Sample To Some Testing
    Process

84
Sampling Considerations
  • Responders Are Often Required To Respond To
    Incidents Involving Abandoned Drums, As Well As
    Clandestine Laboratory Operations.
  • The Following Are Some Basic Considerations That
    Are Applicable At Most Scenarios Where Samples
    May Be Collected
  • Personal Safety And Avoiding Contamination Of
    Samples Are Key Principles In Any Sampling
    Operation.
  • Collect The Samples From An Upwind Position.
  • Wide Mouth Containers Should Be Used When
    Collecting Liquid Samples, As Possible.

85
Sampling Considerations
  • Once The Sample Is Properly Collected, Take It To
    A Safe Testing Location In The Warm Zone.
  • Any Materials And Equipment Used For Evidence
    Collection Must Be Certified Clean, Kept
    Sealed, And Only Used One Time To Collect Each
    Sample.
  • If A Sample May Become Part Of A Criminal Or
    Regulatory Investigation, Chain Of Custody
    Procedures Must Be Followed And Documented.
  • When Collecting Evidence Samples, Additional
    Concerns Include The Following
  • A Sampling Plan Should Initially Be Established
    That Clearly
  • Sampling Tools And Gloves Must Only Be Used One
    Time For Each Sample.

86
Sampling Considerations
  • Collected Samples Should Be Transported Or Stored
    Away From Unused Tools, Equipment And Other
    Chemicals To Avoid The Potential Of
    Cross-contamination.
  • All Sample Containers Should Be Clearly Labeled
    With The Appropriate Identifying Information.
  • Control Blanks Should Be Provided As Part Of The
    Sampling Process To Later Assess
    Cross-contamination And Systematic Contamination
    Issues.
  • Sample Containers That Are Certified As Clean
    Will Have A Letter Stating That They Are Cleaned
    To Some Specification.

87
Sampling Considerations
  • All Sample Collection Should Be Incorporated Into
    The Overall Evidence Collection Process
  • Protect Evidence Samples Form Heat And Direct
    Sunlight, And Keep As Cool As Possible.
  • Before Any Evidence Is Shipped Or Transported To
    A Lab, Ensure That It Has Been Screened For Fire,
    Corrosive, Toxic, And Radioactive Hazards.
  • Chain Of- Custody Must Be Maintained Throughout
    The Course Of The Event..

88
Sampling Equipment
  • The Following General Supplies And Equipment Are
    Commonly Used For Collecting Samples
  • Nonsparking Bung Wrench.
  • Glass Tube Or Disposable Polypropylene/Pvc
    Bailer.
  • Coliwasa Waste Samplers
  • Nonsparking Sample Pole, Extendible To 10 Feet.
  • Glass And Plastic Sample Cups And Bottles.
  • Plastic Bagspositive Seal Is Preferred With
    Evidence Tamper Proof Bags.
  • Bomb Sampler Or Weighted Bottle Sampler.

89
Sampling Equipment
  • In Addition, The Following Tools And Equipment
    Are Likely To Be Used When Collecting Specific
    Forms Of Materials
  • Liquid Samplingtransfer Pipettes, Syringe, And
    Tubing.
  • Solid Samplingstainless Steel Spoons, Scoops,
    Scalpels, And Spatulas.
  • Wipe Sampling For Residuesnylon Or Dacron Swabs,
    Transfer Swabs, Cotton Or Synthetic Gauze And
    Forceps Are Used To Collect The Sample.

90
Sampling Methods And Procedures
  • Accepted Methods For Collecting Samples For
    Various Scenarios Include The Following
  • Drums
  • When Opening A Drum To Collect A Sample, Use A
    Nonsparking Bung Wrench. Manual Drum Opening
    Operations Should Be Performed Only With
    Structurally Sound Drums.
  • When Dealing With Flammable Liquids, Bung Caps
    Should Be Unscrewed Very Slowly, At Approximately
    .25 Inches Per Movement.

91
Sampling Methods And Procedures
  • Sumps And Wells
  • Puddles
  • Slick On Top Of Water
  • Heavier Than Water Unknowns (From Underwater)
  • Deep Holes
  • Dry Piles Of Solids

92
Managing Hazard Information
  • In The Process Of Evaluating Risks, Response
    Personnel Will Be Gathering And Updating Data And
    Information From Various Sources.
  • To Minimize These Problems And Concerns,
    Responders Should Prioritize Their Information
    Requirementswhat Do I Need To Know Right Now, In
    1 Hour, And In 8 Hours?
  • Many Responders Rely On Printed Data Forms And
    Checklists To Ensure That All Information
    Requirements Have Been Prioritized And Addressed.

93
Evaluating Risks
  • Risk Evaluation Is The Most Critical Task
    Performed By Emergency Responders.
  • To Understand The Risk Evaluation Process At A
    Hazmat Incident, Think Of It From A Systems
    Perspective. The Input Factors That Must Be
    Considered At A Hazmat Incident Include
  • Hazardous Material(s) Involved
  • Type Of Container And Its Integrity
  • Environment Or Location Where The Incident
    Occurs And
  • Resources And Capabilities Of Emergency
    Responders.

94
Evaluating Risks
  • Basic Principles
  • All Emergencies Consist Of A Series Of Events
    That Occur In Some Logical Sequence
  • The Overall Objective Of Emergency Responders At
    Any Emergency Is To Favorably Change Or Influence
    The Outcome.
  • To Determine Whether Or Not To Intervene,
    Responders Must First Estimate The Likely Harm
    That Will Occur Without Intervention. Simply,
    What Will Happen If You Do Nothing?
  • Visualize The Likely Behavior Of The Hazardous
    Material And/Or Its Container, Along With The
    Likely Harm Associated With That Behavior
  • Describe The Outcome Of That Behavior.

95
Evaluating Risks
  • To Visualize Likely Behavior, Five Basic
    Questions Must Be Addressed
  • Where
  • How
  • Why
  • What Harm
  • When

96
Evaluating Risks
  • The Factors That Will Affect Hazmat Behavior,
    Including The Following
  • Inherent Properties And Quantities Of The
    Materials Involved
  • Built-in Design And Construction Features Of The
    Container
  • Natural Laws Of Physics And Chemistry, As These
    Will Influence Dispersion Patterns And Where The
    Product Will Go Once It Is Released From Its
    Container
  • Pertinent Environmental Factors - Terrain,
    Weather And Atmospheric Conditions, Wind
    Direction And Speed

97
Behavior Of Hazmats And Containers
  • All Hazmat Releases Will Follow A Logical
    Sequence Of Events, Regardless Of The Hazard
    Class Involved.
  • Events Analysis Is Defined As The Process Of
    Breaking Down Complex Actions Into Smaller, More
    Easily Understood Parts.
  • It Helps Responders
  • To Understand, Track, And Predict A Given
    Sequence Of Events
  • Decide When And How To Change That Sequence.

98
Behavior Of Hazmats And Containers
  • An Easy Way To Visualize Hazmat Behavior Is By
    Using The General Hazardous Materials Behavior
    Model Or GHBMO, Pronounced Gebmo.
  • Originally Developed And Published By Ludwig
    Benner Of The National Transportation Safety
    Board (NTSB) And Published In 1978
  • The GHBMO Is An Excellent Tool For Understanding
    And Predicting The Behavior Of The Container And
    Its Contents At A Hazmat Incident.

99
General Hazardous Materials Behavior Model
100
Stress Event
  • Stress Is Defined As An Applied Force Or System
    Of Forces That Tend To Either Strain Or Deform A
    Container (External Action) Or Trigger A Change
    In The Condition Of The Contents (Internal
    Action).
  • Three Types Of Stress
  • Thermal Stress
  • Mechanical Stress
  • Chemical Stress

101
Breach Event
  • If A Container Is Able To Adapt To The Stress,
    The Incident Will Be Stabilized At That Point.
  • When The Container Is Stressed Beyond Its Limits
    Of Recovery It Will Open Up Or Breach.
  • Different Containers Breach In Different Ways
  • Glass Bottles Shatter
  • Bags Tear
  • Pressure Cylinders Split
  • Drums Tear

102
Breach Event
  • There Are Five Basic Types Of Breach Behaviors
  • Disintegration
  • Runaway Cracking
  • Failure Of Container Attachments
  • Container Punctures
  • Container Splits Or Tears

103
Release Event
  • Once A Container Is Breached, The Hazardous
    Material Is Free To Escape In The Form Of Energy,
    Matter, Or A Combination Of Both.
  • There Are Four Types Of Release
  • Detonation
  • Violent Rupture
  • Rapid Relief
  • Spills Or Leak.

104
Engulfing Event
  • Once The Hazardous Material And/Or Energy Is
    Released, It Is Free To Travel Or Disperse,
    Subsequently Engulfing An Area.
  • To Visualize The Area The Hazmat And/Or Energy Is
    Likely To Engulf, Consider The Following
    Questions
  • What Is Jumping Out At You?
  • What Form Is It In?
  • What Is Making It Move?
  • What Path Will It Follow?
  • What Dispersion Pattern Will It Create?

105
Engulfing Event
  • These Answers Will Help Responders To Predict And
    Define (Visualize) Where The Hazardous Material
    And/Or Its Container Will Go When Released.
  • Responders Can Then Determine The Primary Danger
    Zone And Their Exposures.

106
Engulfing Event
  • First Responders Routinely Use The Emergency
    Response Guidebook Table Of Initial Isolation
    And Protective Action Distances To Initially
    Estimate The Area Potentially Impacted By A
    Hazmat Release
  • Common Plume Dispersion Models Include
  • ALOHA (Part Of The CAMEO System)
  • CHARM (Complex Hazardous Air Release Model
    Software).

107
Impingement (Contact) Event
  • As The Hazardous Material And/Or Its Container
    Engulf An Area, They Will Impinge On Or Come In
    Contact With Exposures.
  • Impinged Exposures May Or May Not Suffer Any
    Harm.
  • Impingements Are Categorized Based On Their
    Duration.

108
Impingement (Contact) Event
  • Short-term Impingements (I.E., A Transient Vapor
    Cloud) Have Durations Of Minutes To Hours.
  • Medium-term Impingements May Extend Over A Period
    Of Days, Weeks, And Even Months.
  • Examples Include Lingering Pesticide Residues
    Resulting From Fires Or Spills, And Asbestos
    Remediation Following A Process Unit Fire Or
    Explosion.
  • Long-term Impingements Extend Over Years And
    Perhaps Even Generations.
  • Examples Include The Contamination Of Groundwater
    Supplies, And Radioactive Material Clean-up
    Operations At Three Mile Island And Chernobyl.

109
Impingement (Contact) Event
  • Estimating Impingements Within An Engulfed Area
    Must Include Consideration Of All Of The
    Following Factors
  • Harmful Characteristics Of The Material Released
    (E.G., Flammable, Toxic, Reactive, Etc.)
  • Concentration Of The Hazardous Material
  • Duration Of The Impingement
  • Characteristics Of The Exposure (I.E.,
    Vulnerability)

110
Harm Event
  • Before Responders Can Favorably Influence The
    Outcome Of A Hazmat Incident, They Must First
    Understand What Harm Is Likely To Occur Within
    The Engulfed Area If They Do Not Intervene.
  • Harm Types
  • Thermal
  • Toxicity / Poisons
  • Radiation
  • Asphyxiation
  • Corrosivity
  • Etiologic
  • Mechanical

111
Harm Event
  • Three Factors Directly Influence The Level Of
    Harm
  • The Timing Of The Release (Speed Of Escape And
    Travel, Length Of Exposure)
  • The Size Of The Dispersion Pattern And The Area
    Covered
  • The Lethality Of The Chemicals Involved
    (Concentration Of The Chemical Or Dosage
    Received).

112
Estimating Outcomes
  • Responders Should Initially Determine Exactly
    Where, In The Sequence Of Events, This Particular
    Incident Is.
  • In A Complex Incident, Such As A Major Train
    Derailment Or A Major Fire In A Petrochemical
    Process Area, Multiple Containers May Be At
    Different Stages Of The Hazmat Behavior Sequence
    Simultaneously.
  • The GHMBO Provides Responders With The Mental
    Framework To Assess Incident Potential And
    Estimate Outcomes Within The Engulfed Areas.

113
Estimating Outcomes
  • Key Factors That Should Be Evaluated To Estimate
    Outcomes In The Engulfed Area Will Include
  • The Size And Dimension Of The Engulfed Area.
  • The Number Of Exposures Within The Engulfed Area,
    Including People, Property, And Critical Systems.
  • The Concentration Of Bad Stuff Within The
    Engulfed Area.
  • The Extent Of Physical, Health And Safety Hazards
    Within The Engulfed Area.
  • Areas Of Potential Harm.

114
Developing The Incident Action Plan
  • The Incident Action Plan Is Developed Based Upon
    The IC's Assessment Of
  • Incident Potential (I.E., Visualizing Hazardous
    Materials Behavior And Estimating The Outcome Of
    That Behavior),
  • The Initial Operational Strategy.
  • Strategic Goals Are The Broad Game Plan Developed
    To Meet The Incident Priorities
  • Life Safety
  • Incident Stabilization
  • Environmental
  • Property Conservation

115
Developing The Incident Action Plan
  • Several Strategic Goals May Be Pursued
    Simultaneously During An Incident. Examples Of
    Common Strategic Goals At Hazmat Incidents
    Include The Following
  • Rescue
  • Public Protective Actions
  • Spill Control (Confinement)
  • Leak Control (Containment)
  • Fire Control
  • Recovery

116
Developing The Incident Action Plan
  • Tactical Objectives Are Specific And Measurable
    Processes Implemented To Achieve The Strategic
    Goals.
  • Tactical Response Objectives To Control And
    Mitigate The Hazmat Problem May Be Implemented In
    Either An Offensive, Defensive Or Nonintervention
    Mode.
  • Offensive Mode
  • Defensive Mode
  • Nonintervention Mode

117
Developing The Incident Action Plan
  • Offensive Mode. These Are Aggressive Leak,
    Spill, And Fire Control Tactics Designed To
    Quickly Control Or Mitigate The Emergency.
  • Defensive Mode. These Are Less Aggressive Spill
    And Fire Control Tactics Where Certain Areas May
    Be Conceded To The Emergency, With Response
    Efforts Directed Toward Limiting The Overall Size
    Or Spread Of The Problem.
  • Nonintervention Mode. Nonintervention Is
    Essentially "No Action." Essentially, The Risks
    Of Intervening Are Unacceptable When Compared To
    The Risks Of Allowing The Incident To Follow A
    Natural Outcome, Such As Scenarios With A High
    BLEVE Or Explosion Potential.

118
Developing The Incident Action Plan
  • Most Operations Will Begin From A Defensive Point
    Of View. The Most Important Question The IC
    Should Ask Is, "What Happens If I Do Nothing?"
  • Defensive Tactics Are Always Preferable Over
    Offensive Tactics If They Can Accomplish The Same
    Objectives In A Timely Manner.

119
Evaluating Risks Special Problems
  • Three Special Situations That Responders Commonly
    Deal With Are
  • Damage Assessment Of Pressurized Bulk Transport
    Containers
  • The Behavior Of Chemicals And Petroleum Products
    When Released Underground
  • The Behavior Of Hazmats In Sewer Collection
    Systems.

120
Damage Assessment Of Pressurized Containers
  • Bulk Transport Pressurized Containers Regularly
    Sustain Extensive Mechanical Stress And Damage In
    Rollovers And Accidents Without Releasing Their
    Contents.
  • Responders Can Be Confronted With A Variety Of
    Pressurized Containers, Including Cylinders,
    Cargo Tank Trucks (Mc-331), And Railroad Tank
    Cars (E.G., DOT-105, 112, And 114 Tank Cars).

121
Damage Assessment Of Pressurized Containers
  • The Violent Rupture Of Pressurized Containers Can
    Be Triggered By Two Related Conditions
  • The Presence Of A Crack In The Container Shell
    Associated With Dents And Rail Burns
  • The Thinning Of The Tank Shell As A Result Of
    Scores, Gouges, And Thermal Stress.

Score
Gouge
122
Damage Assessment Of Pressurized Containers
  • Key Factors That Affect Tank Damage Severity Are
    As Follows
  • Specification Of The Steel
  • Internal Pressure
  • Damage Affecting The Heat-affected Zone Of The
    Weld
  • Cold Work
  • Rate Of Application

Heat Affected Zone
Weld
Crown
Tank Metal
Inside
123
Damage Assessment Of Pressurized Containers
  • Gather Information Concerning The Type Of
    Container (E.G., DOT Specification Number),
    Material Of Construction (E.G., Aluminum, Steel),
    And Internal Pressure.
  • Using Pressure Gauges, Attached To Sample Lines,
    Gauging Device, Fittings, And So On.
  • Use Of Temperature Gauges With Vapor
    Pressure/Temperature Conversion Charts.

124
Damage Assessment Of Pressurized Containers
  • Using Ambient Temperature, Recognizing That The
    Temperature Of The Tanks Contents May Lag
    Ambient Temperatures Up To 6 Hours.
  • Determine The Amount Of Material In The
    Container.
  • Determine The Type Of Stress Applied To The
    Container
  • Thermal
  • Mechanical
  • Combination

125
Damage Assessment Of Pressurized Containers
  • Evaluate The Stability Of The Container.
  • Examine All Accessible Surfaces Of The Container,
    Paying Attention To The Types Of Damage And The
    Radius (I.E., Sharpness) Of All Dents.

126
Damage Assessment Of Pressurized Containers
  • Experience Shows That The Most Dangerous
    Situations Will Include The Following
  • Cracks In The Base Metal Of A Tank Or Cracks In
    Conjunction With A Dent, Score, Or Gouge.
  • Sharply Curved Dents Or Abrupt Dents In The
    Cylindrical Shell Section That Are Parallel To
    The Long Axis Of The Container.
  • Dents Accompanied With Scores And Gouges.
  • Scores And Gouges Across A Containers Seam Weld
    Or In The Heat Affected Zone Of The Weld.

127
Movement And Behavior Of Hazmats Underground
  • When Petroleum Products Or Chemicals Are Released
    Into The Ground, Their Behavior Will Depend On
    Their
  • Physical And Chemical Properties (E.G., Liquid
    Versus Gas, Hydrocarbon Versus Polar Solvent)
  • The Type Of Soil (E.G., Clay Versus Gravel Versus
    Sand),
  • The Underground Water Conditions (E.G., Location
    And Movement Of The Water Table).

128
Movement And Behavior Of Hazmats Underground
  • As With Hazmat Containers And Their Behavior,
    Responders Should Have A Basic Understanding Of
    Geology, Groundwater, And Groundwater Movement To
    Evaluate The Underground Dispersion Of Hazmat
    Releases And Potential Exposures And To Determine
    Potential Outcomes.

129
Geology And Groundwater
  • Generally, Rocks And Soils Consist Of Small
    Fragments Or Sand Grains. When Compressed
    Together, They May Form Small Voids Or Pores.
    Rock Almost Never Has Large Voids, But Sandstone
    And Limestone Have Voids That Are Similar To A
    Fine Sand.
  • In Most Areas, Water Exists At Some Depth In The
    Ground
  • In Most Areas, Groundwater Moves Extremely Slowly

130
Groundwater System
PUMPING WELL
STREAM (OUT FLOW)
WATER TABLE
SEA LAKE
SPRING
SOIL
UNCONFINED AQUIFER
(AQUICLUDE)
CONFINED AQUIFER
BEDROCK
CLAY
131
Behavior Of Hazmats In Soil And Groundwater
  • Hazardous Materials May Be Absorbed Into The Soil
    Through Either Surface Spills Or Leaks From
    Underground Pipelines Or Storage Tanks
  • Flammable And Toxic Gases, Such As Natural Gas,
    Propane, Or Hydrogen Sulfide, Can Also Accumulate
    In Underground Pockets Or Confined Areas

132
Behavior Of Hazmats In Soil And Groundwater
  • The Underground Movement Of Hazmats Follows The
    Most Permeable, Least Resistant Path. For
    Example, The Backfill In Trenches Carrying
    Utility Conduits, Sewers, Or Other Piping Is
    Often Much More Permeable Than The Undisturbed
    Native Soil. Identifying These Conduits Is
    Critical In Identifying Potential Exposures.
  • Liquid Hazmats Which Are Spilled Into Soil Will
    Tend To Flow Downward With Some Lateral Spreading

133
Behavior Of Hazmats In Soil And Groundwater
  • Hazmats That Are Absorbed By The Soil May Move
    Again At Some Later Time As The Water Table Is
    Elevated.
  • Although Combustible Gas Indicators (CGIs) Are
    Excellent Tools For Evaluating Flammable
    Atmospheres, They May Not Be Very Effective For
    Assessing Low-level Flammable Concentrations Such
    As Found With Subsurface And Sewer Spills.

134
Behavior Of Hazmats In Soil And Groundwater
  • Hazmats That Encounter An Impermeable Layer Will
    Spread Laterally Until Becoming Immobile Or Until
    The Hazmat Comes To The Surface Where The
    Impermeable Layer Outcrops.
  • Hydrocarbon Liquids Will Not Mix With Water And
    Will Simply Float On The Surface Of The Water
    Table.

135
Spills Into Sewer Collection Systems
  • Sewers, Manholes, Electrical Vaults, French
    Drains, And Other Similar Underground Structures
    And Conduits Can Be Critical Exposures In The
    Event Of A Hazmat Spill.
  • Most Sewer Emergencies Involve Flammable And
    Combustible Liquids. The Probability Of An
    Explosion Within An Underground Space Will Depend
    On Two Factors
  • That A Flammable Atmosphere Exists
  • That An Ignition Source Is Present.

136
Types Of Sewer Systems
  • Sanitary Sewers. This Is A Closed System That
    Carries Liquids And Water-carried Wastes From
    Residences, Commercial Buildings, Industrial
    Plants And Institutions, As Well As Minor
    Quantities Of Storm Water, Surface Water, And
    Groundwater That Are Not Admitted Intentionally

137
Types Of Sewer Systems
  • Storm Sewers. This Is An Open System That
    Collects Storm Water, Surface Water, And Street
    Wash And Other Drainage From Throughout A
    Community But Excludes Domestic Wastewater And
    Industrial Wastes.
  • Combined Sewers. Carries Domestic And Industrial
    Wastewater, As Well As Storm Or Surface Water.

138
Wastewater System Operations
  • There Are Four Primary Elements Of A Wastewater
    System
  • Collection And Pumping
  • Filtering Systems
  • Liquid Treatment Systems
  • Solid Treatment Systems.
  • Wastewater, Storm Water, And Surface Water
    Initially Enter The Collection And Pumping System
    Through A Series Of Collectors And Branch Lines
    That Tie Together Small Geographic Areas.

139
Wastewater System Operations
  • Where The Terrain Is Flat, The Collection System
    May Consist Solely Of Gravity Piping. However, In
    Most Areas The Collection System Will Require
    Pumping Or Lift Stations. Most Pumping Stations
    Will Have Two Parts A Wet Well And A Dry Well.
  • Depending On The Type Of Sewer System And The
    Specific Location, Most Areas Are Classified By
    The National Electrical Code As Class I, Division
    2 Areas.

140
Primary Hazards And Concerns
  • There Are Two Basic Scenarios Involving Releases
    Into A Sewer Collection System.
  • An Aboveground Release Where A Spill Flows Into
    The Sewer Collection System Through Catch Basins,
    Manholes, And So On.
  • Underground Tank And Pipeline Leaks Where The
    Product Migrates Through The Subsurface Structure
    Into The Sewer Collection System.
  • With The Subsurface Scenario, Responders Will
    Often Receive A Report Of Hydrocarbon Or Gasoline
    Vapors In An Area, With The Source Of The Odor
    Being Unknown.

141
Primary Hazards And Concerns
  • Some Rules Of Thumb For Evaluating Monitoring
    Readings Are As Follows
  • If Readings Are High And Then Drop Off Or
    Dissipate In A Relatively Short Period Of Time,
    The Source Of The Problem Is Often A Spill Or
    Dumping Directly Into The Sewer Collection
    System.
  • If Readings Are Consistent Over A Period Of Time,
    The Source Of The Problem Is Often A Subsurface
    Release, Such As An Underground Storage Tank Or
    Pipeline.
  • Spills And Releases Into The Sewer Collection
    System Will Create Both Fire And Environmental
    Concerns.
  • Fire Concerns
  • Environmental Concerns

142
Coordination With Sewer Department
  • Preplanning With The Sewer Department Is
    Critical. Responders Should Identify Areas Where
    There Is A Probability Of Hazmats Entering The
    Sewer Collection System And Discuss Procedures
    And Tactical Options For Handling Such An
    Emergency
  • When An Emergency Occurs, A Sewer Department
    Representative Should Be Requested On Scene As
    Soon As Possible.
  • Effective Use Of Sewer Maps Will Require A Sewer
    Department Representative Who Is Familiar With
    The Unique Aspects Of The Local System
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