OF HAZARDOUS MATERIALS
|A good working definition
of a hazardous material is provided by the California Office of Emergency
Services (1982) in the State Hazardous Materials Contingency Plan:
A hazardous material
is a substance or combination of substances which, because of quantity,
concentration, physical, chemical or infectious characteristics may either:
- cause, or significantly
contribute to an increase in deaths or serious illness; or
- pose a substantial present
or potential hazard to humans or the environment.
More specifically, hazardous
materials have one or more of the following properties:
||corrosive or irritant;
||thermally unstable or
||poisonous (including carcinogens,
mutagens, and teratogens).
MATERIALS ARE EVEN LOCATED IN RETAIL AND COMMERCIAL AREAS!
While hazardous materials are
commonly associated with manufacturing and industrial areas, they are
also associated with retail and commercial businesses.
||Gas stations have gasoline,
oils, and cleaning solvents.
||Retail stores sell automotive
products, pesticides, cleaning supplies, paints, and swimming pool
||Warehouses and transfer
facilities may temporarily or commonly handle hazardous materials.
||Plating, printing shops,
dry cleaners all have specialty chemicals necessary for their operations.
have refrigeration facilities that may contain hazardous materials.
||Even something as innocuous
as a florist has helium to fill balloons.
a number of different effects.
- Almost all hazardous
materials incidents result from ground shaking. One depiction of
the ground shaking hazard are ABAG's ground
shaking hazard maps. However, the number and severity of hazardous
materials incidents depends not only on the severity of shaking, but
also on the design of facilities. For example, unreinforced masonry
and poorly engineered tilt-up concrete and concrete frame buildings
can be quite susceptible to catastrophic structural damage. In addition,
the shaking damage to contents increases higher up in buildings, particularly
in flexible steel-frame buildings.
- Fault rupture, or surface
rupture, commonly occurs during earthquakes in California because
the earthquakes originate relatively near the earth's surface. The ground
surface ruptures, or breaks, as the ground on one side moves relative
to the ground on the other side. The displacement can be vertical, horizontal,
or a combination of both and may be only a few inches or several feet.
Any buildings or pipelines built across the fault trace will almost
certainly be deformed or destroyed. While California's Alquist-Priolo
Fault Special Studies Zones Act prevents buildings for human occupancy
from being constructed across an active fault, buildings built prior
to the Act's passage in the early 1970s, as well as pipelines, rail
lines, or roads, are exempt. These infrastructure lifelines must cross
faults in California or our principal urban areas would not function.
- Liquefaction is a process
in which loose water-saturated sands and other granular materials suddenly
lose strength when shaken. The lurching and sliding that occurs can
cause severe damage to structures built upon, or pipelines constructed
within, those deposits. This problem occurred in the Lake Merced area
during the Daly City earthquake of 1957, as well as the Oakland approach
to the Bay Bridge and the Marina District of San Francisco during the
Loma Prieta earthquake of 1989. The susceptibility of materials to liquefaction,
as well as the hazard posed by these materials when shaken (particularly
to infrastructure) are discussed and mapped in the liquefaction
section of this web site.
- Earthquake-triggered landslides
can occur in hillside areas. Because few businesses are located in these
areas, the principal impact of these slides will be on roads and pipelines.
- Tsunamis (great waves often
called "tidal" waves that originate in the ocean and have
nothing to do with the tides) and seiches (waves that originate in closed
or semi-closed bodies of water such as reservoirs) are a potential threat
to low-lying waterfront areas, particularly facing the Pacific Ocean
rather than in San Francisco Bay. Seaside shopping areas, marinas, and
port areas are the most vulnerable. More information on this hazard
is contained in the tsunami
section of this web site.
|San Andreas Fault|
photo courtesy of USGS
The types of failures which cause
hazardous materials releases during earthquakes include:
|Photo courtesy of
- building structural failures.
- dislodging of asbestos
or encapsulated asbestos.
- underground pipeline breaks
due to soil movement.
- above-ground pipeline breaks
- breaks in short connector
pipes due to differential movement between pipes and structures.
- impact from other structures
- damage from failing
- cylindrical storage tank
failures due to "elephant's foot"
buckling, weakening from corrosion, or sloshing of contents.
- toppling of elevated tanks.
- shifting and overturning
of horizontal tanks;
- sloshing from open-topped
- industrial equipment problems
due to sliding or overturning,
or internal failures.
- falling containers and
shelves, particularly in:
- hospital, school or
business laboratories; or
- liquor, drug or grocery
factors that can complicate the ability to respond to these releases, include:
- breakdowns in utilities,
including communications, water, and power.
- people not following established
procedures or not using restraining devices.
- malfunctions of control
or alarm systems.
- shortages of emergency
and clean-up personnel.
- disruptions of transportation
- indirect impacts due to
damage to raw material suppliers or equipment suppliers.
summary highlights the findings of a research project described in an ABAG
Hazardous Materials Problems
During Earthquakes: A Guide to Their Cause and Mitigation.
The research on which the
Guide is based included an examination of records of hazardous
materials problems collected by others, as well as ABAG staff interviews
with a number of local governments and private businesses with first-hand
experiences in the Coalinga, Livermore, Loma Prieta, and Whittier earthquakes
A companion document subtitled
Background Materials contains checklists and guidelines,
general articles by other researchers, samples of company and local government
programs, liability and regulatory background information, and extensive
lists of other references. In addition, a database of known hazardous
material releases in 29 past earthquakes is available.
The principal objective
of this ABAG project was to help those responsible for business and government
programs relating to hazardous materials or earthquakes do a better job
of mitigating some of these joint problems. We can learn from the past
and we can learn from each other. The project was initiated before the
Loma Prieta earthquake in October 1989. That earthquake confirmed earlier
conclusions, yet provided additional information on what types of mitigation
measures tend to work, and what types tend to be nothing but "false friends."