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.

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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.

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Introduction

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

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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

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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.

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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.

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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

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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.

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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

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General Chemical Terms And Definitions

• Ionic Bonding
• Covalent Bonding
• Organic Materials
• Inorganic Materials
• Hydrocarbons
• Saturated Hydrocarbons
• Unsaturated Hydrocarbons
• Aromatic Hydrocarbons
• Halogenated Hydrocarbons

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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

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Physical Properties

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

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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.

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Flammability Hazards

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

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Reactivity Hazards

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

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Reactivity Hazards

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

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Corrosivity Hazards

• Corrosivity
• Acids
• Caustics
• Ph
• Strength
• Concentration

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Radioactive Materials

• Radioactivity
• Activity
• Dose
• Dose Rate
• Half-life

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Chemical And Biological Agents/Weapons

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

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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.

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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

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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.

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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.

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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 [phone] 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.

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Other Technical Information Numbers

• CANUTEC (Canadian Transport Emergency Centre) Is
  Operated By Transport Canada And Can Be Contacted
  At [phone]. The General Information Number
  Is [phone].
• 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.

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Technical Information Centers

• U.S. Coast Guard And The Department Of
  Transportation National Response Center (NRC) At
  [phone], Or At [phone] For Those
  Without 800 Access.
• The NRC (National Response Center)
• The Agency For Toxic Substances And Disease
  Registry (ATSDR) At [phone].
• National Animal Poison Control Center (NAPCC) At
  [phone] Or [phone].
• National Pesticide Information Center (NPIC) At
  [phone].

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
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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.

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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.

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Corrosive Monitors

• APPLICATION
• METHODS OF OPERATION
• GENERAL COMMENTS

57
Radiation Survey Monitors

• APPLICATION
• METHODS OF OPERATION
• GENERAL COMMENTS

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Oxygen Monitors

• APPLICATION
• METHODS OF OPERATION
• GENERAL COMMENTS

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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

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Photo-Ionization Detectors (PID)

• APPLICATION
• METHODS OF OPERATION
• GENERAL COMMENTS

63
Flame Ionization Detectors (PID)

• APPLICATION
• METHODS OF OPERATION
• GENERAL COMMENTS

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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.

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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.

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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