HAZARD
IDENTIFICATION
Gaston County Emergency Operations Plan
Updated:
April 29, 2008
Wildfire / Forest Fires:
There are three types of
wildfires.
Surface Fire: |
This
type burns slowly along the floor of a forest. This is
the most common type of wild fire. This type of fire can
damage or
even kill trees.
|
Ground Fire: |
Usually occurs from a
lightning strike. This type of fire burns on or below
the forest floor.
|
Crown Fire: |
This fire is quickly
spread by the wind. It tends to jump among the crowns of
trees.
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All
are generally characterized by very thick smoke. |
|
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Earthquake:
An earthquake is a series of vibrations induced in the earth's
crust by the abrupt rupture and rebound of rocks in which
elastic strain has been slowly accumulating. It is caused by a
slip on a fault, which is a thin zone of crushed rock between
two blocks of rock. The fault can be any length, from a few
millimeters to thousands of kilometers. It is a fracture in the
crust of the earth along which rocks on one side have moved
relative to those on the other side. An earthquake occurs when
stresses in the earth's outer layer push the sides of the fault
together. Stress builds up and the rocks slips suddenly,
releasing energy in waves that cause the shaking.
Earthquakes can
cause severe damage to property and extensive loss of life. An
earthquake will not kill by itself. However, an earthquake may
cause extensive structural damage and collapse that could cause
fatalities and injury.
Earthquakes
can occur at any time of the day and are not related to weather
patterns. An earthquake cannot be prevented, although mitigation
measures can be taken, particularly structure measures, to
reduce the impact that an earthquake has on the surface.
The National
Earthquake Information Center records 12,000 to 14,000
earthquakes a year. The majority are very low vibrations and
cannot be felt by people on the surface.
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Flooding:
Flooding occurs from a number of weather and non-weather related
reasons. Floods typically occur from prolonged rainfall, but
they can also occur from snowmelt, ice jams, and dam
failures. Floods also occur in all 50 states, particularly in
low-lying communities, near a water source, or downstream from a
dam.
Flooding can
cause destruction to property and injury and death to
people. Since 1900, 10,000 lives have been lost to flooding. A
1987 study concluded that over 9 million households and $390
billion in property are at risk from the 1 percent annual chance
flood (100 year flood plain).
There are seven types of flooding in the United States: Riverine
Flooding, Flash Floods, Alluvial Fan Floods, Ice Jam Floods, Dam
Break Floods, Local Drainage or High Groundwater Levels and
Fluctuating Lake Levels.
Riverine Flooding: This
is the most common type of flooding and occurs when a river or
stream overflows its banks. In large rivers, it usually occurs
after a serious, large-scale weather event. In streams, this can
occur from more localized weather systems.
Flash Floods: Flash
floods typically encompass a quick rise of high velocity water
and large amounts of debris. Factors that contribute to flash
flooding include the length and intensity of rain and the
steepness of watershed and stream gradients. Other factors
influencing flash floods include the amount of watershed
vegetation, natural and artificial water storage, and the
configuration of the streambed and floodplain. Flash floods not
only occur from weather systems, but also from a dam failure, or
breakup of ice. This type of flood poses the most risk to
property and lives. Because of the rapid rise of the water
levels, a large percentage of flood deaths occur from motorists
who underestimate the depth and velocity of the floodwaters and
attempt to cross flooded areas. This typically occurs when a
weather event quickly drops an extensive amount of water. Walls
of water from this type of event can reach 15 to 20 feet.
Dam Break Floods / Dam Failure:
Results from structural failures of dams.
As of 2002 there were 87 Dams Registered by the Dam Safety
Program, Division of Land Resources, Department of Environmental
and Natural Resources. These Dams are classified as to potential
hazard as: High (H), Intermediate (I), and Low (L) by the North
Carolina Dam Safety Program in the Division of Land Resources,
Department of Environment and Natural Resources.
Additional information regarding dams
in Gaston County can be found in the
Hazard Mitigation Plan.
Local Drainage
or High Groundwater Levels: Heavy
precipitation from local weather events may produce flooding
outside of delineated flood plains. If the local soil cannot
handle precipitation through infiltration and runoff, the water
may accumulate. During winter, frozen ground and accumulated
snow will contribute to this problem. This type of flooding
generally occurs in flat and urban areas. High groundwater
levels may cause leakage in susceptible basements.
Fluctuating Lake Levels: Lake
levels can change over a short period of time, over a season, or
on a long-term basis. Heavy rain or snow can influence
levels. All lakes are susceptible to changes in water level, but
the problem seems to occur most often in lakes that are
landlocked or have inadequate outlets for maintaining a balance
between in and outflow. These type of lakes can fluctuate from 5
to 15 feet over an extended period of time.
Due to the
severe consequences from flooding, local governments should pay
close attention to flood warnings and forecasts. These
mitigation measures decrease property damage by an estimated $1
billion annually.
The National Weather Service
is responsible legally for weather forecasting and warning. NWS
uses the stream gauging stations that the USGS operates and
maintains nationwide, including 98 percent of gauges used for
real-time forecasting.
In the early
1960s it was recognized that there needed to be a standard of
evaluating flood risk throughout the United States. This
resulted in the 100-year or 1-percent-annual chance flood. This
assessment delineates a degree of risk and damage worth
protecting against, but not deemed to be worthy of imposing
stringent requirements or burdens of excessive costs on property
owners. The 100-year flood represents a compromise between minor
floods and major floods.
Computed water
surface elevations are combined with topographic mapping data to
develop the Flood Insurance Rate Maps (FIRM). This is an
important planning tool to determine where development would
reside within flood prone areas. Insurance companies use the
FIRMs to determine flood insurance rates.
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Drought:
A drought is
roughly defined as a condition of abnormally dry weather within
a geographic region where some rain is usually expected. This is
caused by a lack of precipitation in conjunction with wind, high
temperatures, and low humidity. This lack of rain in a region
results in a number of problems. There are varying degrees of
severity in a drought. This severity depends on the demand on
water in a region, duration and intensity. Problems of a drought
can include:
-
Diminished water supplies or reduction of water quality
-
Undernourished livestock and wildlife
- Crop
damage
-
Increased fire hazards
-
Reduced forest productivity
- Damage
to fish and wildlife habitat
Indirect
Impacts:
- Reduced
income for farmers and agribusiness
-
Increased prices for food and lumber
-
Unemployment
- Reduced
tax revenues because of reduced expenditures
-
Increased crime
-
Foreclosures on bank loans to farmers and agribusiness
There are four
types of drought:
-
Meteorological Drought – This is a reduction of
precipitation over time. This definition is regionally
based. In the United States, this is indicated by less then
2.5mm of rainfall in 48 hours. This is the first indication
of a drought.
-
Agricultural Drought – This occurs when soil moisture cannot
meet the demands of a crop. This type of drought happens
after a meteorological drought but before a hydrological
drought.
-
Hydrological Drought – This type refers to reduction in
surface and subsurface water supplies. It is measured
through stream flow and water levels in lakes, reservoirs,
and groundwater.
-
Socioeconomic drought – This occurs when water shortages
affect people, either in terms of water supply or economic
impacts (i.e., loss of crops so price increases).
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Severe Winter
Storms:
The occurrence of large snowstorms, ice
storms, and severe blizzards has a substantial impact on
communities, utilities, and transportation systems, and often
results in loss of life due to accidents or hypothermia. In
addition to the impacts on transportation, power transmission,
communications, agriculture, and people, severe winter storms
can cause extensive coastal flood-erosion and property loss.
Severe winter storms display themselves in a
wide variety of ways including heavy snow, blizzards, freezing
rain, ice pellets, and extreme cold. Severe winter storms are
extra-tropical cyclones fueled by strong temperature gradients
and an active upper-level jet stream. The storms that hit North
Carolina usually form in the Gulf of Mexico or off the southeast
Atlantic Coast. In North Carolina, very few of these result in a
blizzard.
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Hurricanes:
Hurricanes are
devastating natural events on the east coast. More than 36
million people reside in the counties along the Gulf of Mexico
and the Atlantic Ocean. This exposes a large amount of a state’s
population and property to tropical events.
Hurricanes
have a number of conditions necessary to occur. This includes a
pre-existing weather disturbance, warm tropical oceans,
moisture, and relatively light winds aloft. If these all come
together, they can produce a hurricane which can lead to violent
winds, high waves, torrential rains, storm surge, tornadoes, and
floods. Basically, a hurricane is a type of tropical cyclone,
which is a low pressure system that generally forms in the
tropics.
Hurricane eyes
move around 10 - 15 mph. Hurricanes typically move westward at
first and become stronger as time goes on. Hurricanes then
typically turn from the equator and pick up speed. Most
hurricanes turn east after they reach temperate latitudes. Many
end up as weak storm centers over cool oceans.
If a hurricane
continues to move west and encounters land, strong winds and
heavy rain can hit an area for many hours. As the ‘eye’ of the
hurricane hits an area, the high winds and rain stop. Less then
an hour later, the eye passes and the damaging winds and rains
continue. Hurricanes tend to weaken after reaching land because
they are not receiving energy from the evaporation of warm
seas. The wind also encounters friction from the rougher land
surface. Winds die down first, while heavy rains continue.
When a
hurricane is initially formed, a number of agencies and
departments keep track of its progress. A multitude of
information is collected, including pressure, temperature and
wind speeds. This information is very important to formulate
predictions on landfall and severity, so communities in its path
can be warned.
Housing is very
susceptible to damage from hurricanes. The greatest wind forces
on houses occur on their sides. Since hurricane force winds push
for extended periods of time, it can push a frame out of
alignment or lift it off its foundation. It seeks out weak
points such as windows and doors. The wind can also pick up
heavy debris and smash it against residences. When a wind blows
against a house, it puts pressure on the side it is blowing
against. The opposite side of the house experiences low
pressure. Therefore, if the wind enters the house from the
blowing side (i.e., blowing out a window, etc), the sudden
pressure buildup in the house can cause doors, windows, and
other weak places to pop out. If the wind doesn’t destroy a
house, then residents need to worry about the heavy rain
producing enough floodwaters to enter the house. A typical
hurricane drops 6 – 12 inches of water on the area it
crosses. Tornadoes often form on the fringes of the storm.
Each year
about 10 tropical storms develop. Many of these remain over the
ocean, but approximately 6 become hurricanes each
year. Hurricane strength is defined by the
Saffir/Simpson
Hurricane scale.
The Saffir/Simpson
Hurricane Scale
Category |
Definition-Effects
|
1 |
Winds
: 74-95 mph (64-82 kt)
No real damage to building structures. Damage
primarily to unanchored mobile homes, shrubbery, and
trees. Also, some coastal flooding and minor pier
damage.
|
2 |
Winds
: 96-110 mph (83-95 kt)
Some roofing material, door, and window damage.
Considerable damage to vegetation, mobile homes,
etc. Flooding damages piers and small craft in
unprotected moorings may break their moorings.
|
3 |
Winds
: 111-130 mph (96-113 kt)
Some structural damage to small residences and
utility buildings, with a minor amount of curtain
wall failures. Mobile homes are destroyed. Flooding
near the coast destroys smaller structures with
larger structures damaged by floating debris.
Terrain may be flooded well inland.
|
4 |
Winds
: 131-155 mph (114-135 kt)
More extensive curtain wall failures with some
complete roof structure failure on small residences.
Major erosion of beach areas. Terrain may be flooded
well inland.
|
5 |
Winds
: 155+ mph (135+ kt)
Complete roof failure on many residences and
industrial buildings. Some complete building
failures with small utility buildings blown over or
away. Flooding causes major damage to lower floors
of all structures near the shoreline. Massive
evacuation of residential areas may be required. |
Hurricanes are given names by an
international committee. This reduces confusion when two or more
tropical cyclones occur at the same time. The list repeats
itself every three years, but if a hurricane is especially
damaging, the name is retired.
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Severe
Thunderstorms:
Thunderstorms
are underrated in the damage, injury, and death they can bring.
Lightning precedes thunder because lightning causes thunder. As
lightning moves through the atmosphere, it can generate
temperatures up to 54,000 degrees Fahrenheit. This intense
heating generates shockwaves which turn into sound waves, thus
generating thunder.
Warm, humid
conditions encourage thunderstorms as the warm, wet air updrafts
into the storm. As warm, moisture rich air rises, it forms
cumulus nimbus clouds, thunderstorm clouds, usually with a
flattened top or an anvil shape, reaching to 40,000 feet or
more. If this air is unstable, the conditions are then there to
cause hail, damaging winds and tornadoes.
As a
thunderstorm grows, electrical charges build up within the
clouds. Oppositely charged particles exist at the ground
level. These forces become so strong that the air’s resistance
to electrical flow is overcome. The particles from both top and
bottom then race towards each other to complete a
circuit. Charge from the ground then surges upward at nearly one
third the speed of light to produce lightning.
Each year
lightning kills about 50 – 100 people, mostly during the
spring/summer season. Typical thunderstorms last anywhere from ½
to 1 hour. Most lightning strikes occur in the afternoon. 70%
occur between noon and 6:00pm. This is because as air
temperatures warm, evaporation increases. Sundays have 24% more
deaths from lightning than any other day, followed by
Wednesday. Lightning reports reach their peak in July.
Men are hit by
lightning four times more often then women. Men account for 84%
of lightning fatalities and 82% of injuries. However, the actual
number of deaths and injuries due to lightning have decreased
over the last 35 years. This is attributed to improved forecasts
and warnings, better lightning awareness, more substantial
buildings, socioeconomic changes, and improved medical care.
In the United
States, the
National Weather Service has recorded thousands of deaths
and injuries due to lightning strikes. Only 20% of lightning
strikes cause immediate death. 70% of lightning strike victims
that survive experience residual effects, most commonly
affecting the brain (neuropsychiatric, visual, and auditory).
These effects can develop slowly. Lightning strike
victims have typically been walking in an open field or swimming
before they are struck. Other lightning victims have been
holding metal or composite objects such as golf clubs, fishing
poles, hay forks, or umbrellas.
Damage to
property from direct or indirect lightning can take the form of
an explosion, a burn, or destruction. Damage to property has
increased over the last 35 years. This is probably due to
increased population. The National Weather Service recorded
19,814 incidents of property damage between 1959 and
1994. Yearly losses are estimated at $35 million by the National
Weather Service. This amount is compiled from newspaper reports,
but many strikes are not reported. The
National Lightning Safety Institute estimates damages at $4
to $5 billion. This information is compiled from insurance
reports and other sources that keep track of weather damages.
Thunderstorm winds also cause
widespread damage and death. Thunderstorm ‘straight line’ wind
occurs when rain-cooled air descends with accompanying
precipitation. A thunderstorm is considered severe when winds
exceed 57.5mph. At the very extreme, winds of 160mph have been
recorded. These winds can smash buildings and uproot and snap
trees, and are often mistaken for tornadoes.
‘Downbursts’ can occur during a
thunderstorm. This is an excessive burst of wind that is
sometimes confused with tornadoes. These are defined as a surface
wind in excess of 125 mph caused by a small scale downdraft from
the base of a convective cloud. A downburst occurs when
rain-cooled air within a convective cloud becomes heavier than
its surroundings. Since cool air is heavier than warm air, it
rushes toward the ground with a destructive force, exactly what
triggers the sudden down rush is still unknown.
A downburst appears to strike at a
central point and blow outwards. (Picture a bucket of water
dashed against grass. If it hits straight on, the grass will be
flattened in a circular pattern. If it hits at an angle, the
grass will be flattened in a teardrop pattern.) Downbursts have
resulted in almost 300 deaths in the last ten years.
Downbursts can be further
classified into two categories:
-
Microburst:
Less than 2 1/2 miles wide at the surface, duration less
than 5 minutes and winds up to 146 miles per hour.
-
Macroburst: Greater than 2 1/2 miles wide at the
surface, duration of 5-30 minutes with winds up to 117 miles
per hour.
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Tornadoes:
Tornadoes are
produced during severe thunderstorms, which are created near the
junction between warm, moist air and cold, dry air. Tornadoes
derive their energy from the heat contained in warm, moist air
masses. Tornadoes do not form during every thunderstorm. They
occur when the moist, warm air is trapped beneath a stable layer
of cold dry air by an intervening layer of warm dry air. This is
called an inversion. If this is disturbed, the moist air will
push through the stable air that is holding it down. This warm
air will then condense as the latent heat it holds is released.
This air will then spiral upwards. With the help of different
types of winds, this spiral gains speed, producing a tornado.
A tornado path
is generally less then .6 miles wide. The length of the path
ranges from a few hundred meters to dozens of kilometers. A
tornado will rarely last longer than 30 minutes. The combination
of conditions that cause tornadoes are common across the southern
U.S. in early spring, especially in April and May. Tornadoes have
been recorded as lifting and moving objects weighing more then
300 tons up to 30 feet. They can also lift homes off of their
foundations and move them 300 feet. They collect an incredible
amount of debris which they can whirl out of their winds at
high velocities. Tornadoes are usually accompanied by heavy rain.
Tornadoes can
cause large amounts of property damage, injury, and death.
Although more twisters hit the states that run from Texas up
through Oklahoma, Kansas and into Nebraska, more people are
killed by the tornadoes that land in the Southeast. The reasons
given for the disparity include the different housing, geography
and population density and the greater tendency of tornadoes in
the Southeast to strike at night. Between 1950 and 1997, the
Tornado Alley states of Texas, Oklahoma, Kansas, Nebraska and
Missouri had 13,808 tornadoes, according to data compiled by the
National Storm Prediction Center. In those storms, 1,132 people
died. In Alabama, Arkansas, Louisiana, Mississippi, Georgia,
Florida, Tennessee, North Carolina and South Carolina, there
were 9,178 tornadoes and 1,648 deaths.
The National
Weather Service issues a tornado watch for a specific location
when the conditions are ripe for tornadoes and they are expected
within a few hours. A tornado warning is issued when a tornado
has actually been sighted or indicated by weather radar.
Fujita Tornado Scale:
Category |
Maximum Wind Speeds |
Equivalent Saffir-Simpson
Scale |
Typical Effects |
F0 |
40 – 72mph |
NA |
Gale
Tornado. Light Damage: Some damage to chimneys; breaks
twigs and branches off trees; pushes over shallow-rooted
trees; damages signboards; some windows broken;
hurricane wind speed begins at 73mph. |
F1 |
73 – 112 mph |
Cat 1/2/3 |
Moderate
Tornado. Moderate damage; Peels surfaces off roofs;
mobile homes pushed off foundations or overturned;
outbuildings demolished; moving autos pushed off the
roads; trees snapped or broken. |
F2 |
113 – 157
mph |
Cat 3/4/5 |
Significant
Tornado. Considerable damage: Roofs torn off frame
houses; mobile homes demolished; frame houses with weak
foundations lifted and moved; boxcars pushed over, large
trees snapped or uprooted; light-object missiles
generated. |
F3 |
158 – 206
mph |
Cat 5 |
Severe
Tornado. Severe damage: Roofs and some walls torn off
well-constructed houses; trains overturned; most trees
in forests uprooted; heavy cars lifted off the ground
and thrown; weak pavement blown off roads. |
F4 |
207 – 260
mph |
Cat 5 |
Devastating
Tornado. Devastating damage: Well constructed homes
leveled; structures with weak foundations blown off some
distance; cars thrown and disintegrated; large missiles
generated; trees in forest uprooted and carried some
distance away. |
F5 |
261 – 318
mph |
NA |
Incredible
Tornado. Incredible damage: strong frame houses lifted
off foundations and carried considerable distance to
disintegrate; automobile-sized missiles fly through the
air in excess of 200 ft; trees debarked; incredible
phenomena will occur. |
F6 – F12 |
Greater then
319 mph. |
NA |
The maximum
wind speeds of tornadoes are not expected to reach the F6
wind speeds.
|
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Hazardous Materials:
Any area that manufactures hazardous
materials, or contains transportation routes (roads, rail) that
transport hazardous materials are at risk for a hazardous
material event. Approximately 6,774
HAZMAT (hazardous materials) events occur each year
nationwide. On the average 991 will be railway events. Trucks
are responsible for most of the remainder of events. The average
distance for trip lengths for gasoline transport is 28
miles, 260 miles is the average length for chemical trucks.
Even though trucks account for most accidents, it is railway
transport that has the greatest potential for concern in many
areas. Collisions and derailments can cause very large spills as
it is rare that a single car will be damaged.
Extremely hazardous substances, as defined by the EPA, can
pose as serious threat, whether by rail or other ground
transportation.
An average of 280 HAZMAT spills occur at
fixed sites each year. Natural disasters, such as floods and
earthquakes can cause HAZMAT releases or disturb old HAZMAT
release sites (Superfund sites). These same disasters can make
it difficult to contain these events once they occur. Also,
natural disasters can limit access to the spill, waterlines for
fire suppression may be broken and response personnel and
resources may be limited. Flooding and high winds can quickly
spread the contaminant, threatening agriculture, water supply
and air.
HAZMAT releases pose short and long term
threats to people, wildlife, vegetation and the
environment. HAZMAT materials can be absorbed through
inhalation, ingestion or direct contact with the skin.
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Aircraft Accidents:
An occurrence associated with the operation of an aircraft which
takes place between the time a person boards the aircraft with
the intention of flight, until such time as all such persons
have disembarked, and in which any person suffers a fatal injury
or serious injury as a result of being in or upon the aircraft
or by direct contact with the aircraft or anything attached to
the aircraft, or an occurrence in which the aircraft receives
substantial damage.
The
NTSB (National Transportation Safety Board) is an
independent federal agency charged by Congress with
investigating every civil aviation accident in the US and
significant accidents in other modes of transportation and
issuing safety recommendations aimed at preventing future
accidents.
Aviation
Accident groups are:
-
Large
Airlines
(air carriers) in scheduled and non-scheduled service
operating aircraft with a seating capacity of more than 30
seats or a maximum payload capacity of more than 7,500
pounds carrying passengers or cargo for hire or
compensation.
-
Commuter
carriers
in scheduled service operating small aircraft (30 seats or
less) carrying passengers for hire or compensation
performing at least five scheduled round trips per week or
caries cargo or mail.
-
"On-demand" air taxis
in unscheduled service operating small aircraft (30 seats or
less) carrying passengers or cargo for hire or compensation
excluding commuter air carriers.
-
General
aviation
is all other civil aircraft.
|
Railway Accident / Incident:
Railway accidents / incidents may involve mass causality events,
hazardous materials events and explosive hazard events. Because
many accidents may occur in remote areas, this will hamper
rescue or recovery efforts as well as containment of hazardous
materials. Emergency response equipment may not have accessible
areas in which to stage personnel or equipment.
In Gaston County
Southern Railway runs through the middle of Gaston
County to include the municipalities of Gastonia,
Cramerton, Bessemer City, Belmont, McAdenville, Lowell
and Ranlo.
CSX Railroad runs through northern Gaston County to
include the municipalities of Stanley, Mount Holly, and
Cherryville.
The Federal Railroad Administration of the Department of
Transportation classifies railway accidents involving passenger
trains, freight trains and subway trains. In 2004, the latest
year that data are available, the freight railroad industry
produced over 1.66 trillion ton-miles that generated revenue of
$42.2 billion. Seven major railroad systems accounted for 93
percent of the industry's total revenue even though the rail
industry is composed of over 500 carriers. The Surface
Transportation Board (the federal agency with jurisdiction over
the economic regulation of railroads) classified seven railroads
as meeting the Class I threshold with revenues greater than or
equal to $289.4 million in 2004. In addition, according to the
Association of American Railroads, there were 31 regional
railroads and over 500 local (shortline or switching and
terminal) railroads. The industry originated over 34 million
carloads on a network consisting of nearly 141,000 miles of
road. The industry employed 177,000 employees.
Many railway spurs run throughout the county serving
business and industry.
The NC Department of Transportation has a rail system
that is not routinely used, however is available for use
as an alternative transportation route.
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Terrorist Activity:
Terrorism is
the use of force or violence against persons or property in
violation of the criminal laws of the United States for purposes
of intimidation, coercion or ransom. Terrorists often use
threats to create fear among the public, to try to convince
citizens that their government is powerless to prevent terrorism
and to get immediate publicity for their causes. The act of
terrorism is a crime. The results of a terrorist act may be
catastrophic.
The
Federal Bureau of Investigation (FBI) categorizes terrorism
in the United States as one of two types-domestic terrorism or
international terrorism.
Domestic terrorism involves groups
or individuals whose terrorist activities are directed at
elements of our government or population without foreign
direction.
International terrorism involves
groups or individuals whose terrorist activities are
foreign-based and/or directed by countries or groups outside the
United States or whose activities transcend national boundaries.
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Fixed Nuclear Facility:
(Also see the
Emergency Plan for Nuclear Power Stations.)
Gaston
County falls within the Emergency Planning Zone (EPZ) of
the Duke Energy, McGuire Nuclear Station and Catawba
Nuclear Station. This area has a radius of about 10
miles around the nuclear facility. The 50-mile radius of
the ingestion exposure (IPZ) is based on a number of
considerations. One of those considerations is that the
downwind range, potentially threatened by contamination,
would generally be limited to about 10-miles or less
from the power plant because of wind shifts, wind speed
during the release, and radioactive decay. Another is
that the particulate material from a radioactive plume
would have been deposited on the ground within 50 miles
of the facility. Considerable information regarding
nuclear facilities can be found in the emergency
operations plan and in emergency response procedures for
these nuclear stations.
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Power Failure:
A major
electrical power failure is defined as a failure of the
electrical distribution system that will exceed twenty-four
hours in duration and affect greater than 33% of the
geographical area of the county. Electrical distribution systems
can be interrupted for a number of reasons, but those that have
historically been the main cause are high winds (tornadoes,
hurricanes and severe
thunderstorms) and
severe winter storms, such as ice. A prolonged major
electrical distribution system failure during the middle of
winter accompanied with very cold temperatures can have dramatic
effects on a population.
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Mass Casualty:
Defined as any occurrence in which
twenty (20) or more persons are killed or sustain injury.
Mass casualty incidents are rare but are most likely to occur in
transportation accidents. While mass casualty incidents are
possible in severe weather, they are also rare.
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Large Structural
Fires:
Generally a
large structure is defined as any structure exceeding 25,000
square feet. Large structural fires therefore would include
fully involved structures of this size or greater. Hospitals,
government centers, manufacturing facilities, warehouses, barns,
etc. Multiple stories may be involved as well and constitute
square footage.
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Landfill fires:
Landfill
fires are not restricted to publicly owned landfill operations.
Private landfills, Construction and Demolition landfills are
also included. Landfill fires are perhaps some of the most
difficult fires to fight because they are often deep beneath
tons of debris or other such materials. Landfill fires can be
fueled by methane gas trapped in pockets or by wood and paper
debris. Effective methods of fighting such fires have been
developed by Gaston County and landfill operators.
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Civil
Disorder:
Civil
disorder is most commonly thought of as racial tension, racial
unrest or other connotations and implications regarding race.
Civil disorder is defined however, as unlawful actions by a
civilian population with the intent to demonstrate unlawfully
against the peace and welfare of the government. Also known as
rioting, it is further defined by law as "...a public
disturbance involving an assemblage of three or more persons;
which by disorderly and violent conduct, or the imminent threat
of disorderly or violent conduct, results in injury or damage to
persons or property or creates a clear and present danger of
injury or damage to persons or property."
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Pipeline break /
natural gas disruption:
A gas
pipeline break or rupture is defined as any unintentional break
in the natural gas lines serving the county. Gaston County
natural gas customers are most often served by Piedmont Natural
Gas. LP or liquid propane customers are served by several
smaller companies.
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Other or unknown hazards
(biologics, disease, etc.) :
This particular
threat is perhaps one of the most troubling and causes planners
considerable concern because they are unknown. There are over
60,000 known chemicals as well as hundreds of diseases that
affect human populations as well as livestock and there are
naturally occurring biological concerns. A fire at a plastics
recycling center, for example, may cause a significant local
environmental impact from smoke and water runoff, smoke may be
toxic and cause death or injury to the human population as well
as local livestock. Water runoff may kill aquatic life and
contaminate drinking water supplies.
Additional hazards from smoke may be as minor as traffic
congestion and accidents in the immediate area to long term
breathing difficulty in exposed populations. This one example is
an indicator of an unknown where the original product (plastics)
present little concern, but when burned cause numerous hazards.
Other concerns such as anthrax and foot-and-mouth disease are
often classed as unknowns until laboratory results have been
examined. This can sometimes take days or weeks.
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Waste or Waste water
spills:
The accidental discharge or
release of untreated human and livestock waste into drinking
water reservoirs or water supplies can affect large areas of the
population. Human waste is normally treated by waste water
facilities either municipally owned or privately owned. Strict
standards for water quality exist prior to the release of water
back into creeks, streams or other waterways. Containments and
facilities, through the breakdown of equipment or by accident
can be breached and untreated material can be released causing
potential contamination. On a smaller scale, community septic
systems can overflow causing possible contamination of local
groundwater. In North Carolina the Division of Water Quality,
Department of Environment and Natural Resources is responsible
for monitoring waste water facilities.
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*** End Hazard Identification ***
Last updated: April 29, 2008 | |