Edison Water Quality Laboratory
September 1971
CONTROL OF HAZARDOUS MATERIAL
SPILLS IN THE WATER ENVIRONMENT:
AN OVERVIEW
ENVIRONMENTAL PROTECTION AGENCY • WATER QUALITY OFFICE
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CONTROL OF HAZARDOUS MATERIAL
SPILLS IN THE WATER ENVIRONMENT:
AN OVERVIEW
Ira Wilder and Joseph Lafornara
Hazardous Material Spills Research Section
Environmental Protection Agency
Edison Water Quality Laboratory
Edison, New Jersey
I INTRODUCTION
More than two billion tons of potentially hazardous materials were produced
and handled in the United States during 1968-1969. It is projected that the annual
production quantities of these materials will approximate four billion tons in 1980.
Over 70 percent of these quantities are transported by motor truck, railway, water
barge and pipeline. As long as the tonnage of liquid, solid and gaseous hazardous
chemicals produced, handled, and transported continue to follow the present upward
trend, the accidental spillage of these materials poses a real and growing threat
of pollution to our watercourses.
II EFFECTS
The effects of these materials on watercourses and the plant and animal life
associated with them may vary widely. In general, most chemicals, when present in
the environment above certain critical concentrations, are toxic to biological life
and detrimental to the environment's aesthetic quality. Although many substances
are obviously hazardous to aquatic and marine life due to direct acute toxicity,
other substances are equally detrimental to water ecosystems by virtue of indirect
toxicity resulting from depletion of the dissolved oxygen supply required to support
various life forms. Still others, although originally present at less than toxic
or inhibitory levels, may become concentrated to these levels by residual accumu-
lation through a succession of food chain transfers. In addition to direct effects
of the spilled hazardous materials, there may be other effects of the products of
reaction between the pollutant and water or other materials in the watercourse.
Ill CAUSES
A. General
The accidental entrance of a hazardous material into a watercourse can occur
in a variety of ways. Spills or sudden discharges can result from mechanical mal-
function, collision, fire or human error in connection with rail, highway and
water modes of transportation or with stationary sources such as manufacturing
or storage facilities. The most serious type of spill occurs when a container is
violently ruptured and large quantities of the hazardous material are spilled al-
most instantaneously. In some cases, the material may be discharged directly into
a watercourse, while in others' the spilled material may flow or be washed into
sewers, drainage channels or percolate slowly into ground water supplies.
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B. Transportation Sources
A significant portion of the total problem of hazardous material spills is
caused by transportation accidents. Wnile derailment presents the major potential
for railroad tank car spills, collision and sinking are obvious sources of barge
spills. Spills may also occur at tank truck, tank car and barge loading/unloading
facilities due to defective transfer pump and flange connections, hose failures
and valve packing and seal deficiencies.
C. Stationary Sources
1. One of the largest single sources of pollution incidents in industrial
plants is failure or breakdown of manufacturing or process equipment. These fail-
ures include broken pipelines in chemical plants, leaking tanks, malfunction of
refrigeration equipment, overflowing of chemicals from tanks during manufacture,
faulty pressure gauges and valves, pump breakdown, operational errors, metal failure
due to corrosion in acid transport pipes, explosions and fires. These sources of
pollution incidents are compounded to some degree by the many intentional discharges
of unwanted hazardous materials into our nation's waters.
2. Storage facility spills also contribute to the overall problem. Numerous
fish kills result from leaks from storage tanks and broken lagoon dikes. The leach-
ing action of rain water on open stockpiles of hazardous chemicals stored in the
open at water edge locations has also greatly added to the contamination of our
waterways.
IV CONTROL
A. Prevention
It is generally agreed that the prevention of hazardous material spills con-
stitutes the most desirable method for effective water pollution control. Unfor-
tunately, previous efforts to provide adequate safeguards for handling these
materials and for preventing their release into the aquatic environment have not
been very successful. A recently completed study^', initiated by the Environmen-
tal Protection Agency's Division of Oil and Hazardous Materials, concluded that
there are presently no uniform industry-wide standards in the United States for
spill prevention and, consequently, preventive techniques, equipment and operational
procedures need to be developed to protect the public health and welfare.
B. Countermeasures
1. General
Although prevention remains the first and most important line of defense,
it must be recognized that even with the most comprehensive precautionary tech-
niques, accidents involving the uncontrolled release of detrimental substances to
the environment must be anticipated and appropriate response measures must be de-
veloped to minimize undesirable ecological effects. Existing countermeasure tech-
niques have been developed primarily for continuous discharge waste treatment
systems under controlled conditions. However, because of the rapid response re-
quired in the case of spills, the majority of these available techniques are not
satisfactory for application in the aquatic environment.
Hazardous materials involved in spills which enter a watercourse may be cate-
gorized on the basis of their densities and solubilities in water. The heavier,
insoluble materials such as ethylene dichloride and sulfur will sink to the bottom
of waterways. The removal of these contaminants by physical means, such as suction
or dredge type devices, is a possibility. Less dense water insoluble chemicals
such as decyl alcohol will tend to float. The mechanical separation of these
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materials by confining the spill to a small area by booms and removing the materials
by skimming should be relatively successful. In the case of water soluble materials
such as phenol and acrylonitrile, mechanical means of removal are not possible since
the spilled material will be in solution.
2. Priority Ranking System
Because water soluble chemicals present the greatest threat to the water eco-
system from a countermeasure point of view, a priority ranking system for estimating
the theoretical inherent hazard of these chemicals was prepared as part of an EPA
sponsored state-of-the-art study on hazardous material spills. The ranking sys-
tem is based on (a) the lowest concentration range at which a material impairs any
of the beneficial uses of water, (b) the quantity shipped annually by each mode of
transport and (c) the probability of an accidental spill to surface waters for each
transport mode. Since a material's ranking is then representative of its potential
threat to water quality, it is expected that this system should provide the guide-
lines for determining which chemicals receive the greatest attention relative to the
development of spill countermeasure techniques.
To illustrate this ranking system, the top twenty water soluble substances are
arranged in order of decreasing priority in Table I.
TABLE I
PRIORITY RANKING OF SOLUBLE HAZARDOUS SUBSTANCES
Rank Substance
1 Phenol
2 Methyl Alcohol
3 Cyclic Rodenticides
4 Acrylonitrile
5 Chlorosulfonic Acid
6 Benzene
7 Ammonia
8 Misc. Cyclic Insecticides
9 Phosphorous Pentasulfide
10 Styrene
11 Acetone Cyanohydrin
12 Chlorine
13 Nonyl Phenol
14 DDT
15 Isoprene
16 Xylenes
17 Nitrophenol
18 Aldrin-Toxaphene Group
19 Ammonium Nitrate
20 Aluminum Sulfate
These substances include both organic and inorganic materials and range from solids
to liquids to gases under standard conditions of pressure and temperature.
3. Defensive and Offensive Measures
(2)
The state-of-the-art study also provides a summary of possible measures
that can be employed in responding to hazardous material spills. The counter-
measures are divided into two major classifications: defensive and offensive.
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The defensive measures, which do not counteract the contaminant in the environment,
consist of notifying all downstream water users of the occurrence of a spill and
physically removing all bags, barrels and other containers which may still be leak-
ing into the watercourse. The offensive measures include the following:
(a) Physical Containment - These measures are only applicable to insoluble
hazardous materials which are less dense than water. In most cases the use of pre-
sently available "booming" equipment should be successful when environmental con-
ditions permit.
(b) Physical Removal - This technique offers possibilities for removal of
insoluble materials from watercourses. The use of skimming devices should be rela-
tively effective for removal of materials less dense than water, whereas dredges
and suction devices are potential countermeasures for those chemicals more dense
than water.
(c) Physical Mixing - In the case of spills of certain soluble hazardous
materials which are toxic only at relatively high concentrations, it may be possi-
ble to use agitating devices such as outboard motors to accelerate natural dilution,
and thereby reduce the concentration of the pollutant to a level far below critical
concentrations. It should be emphasized that this method can only be employed for
the small number of materials which are toxic only at high concentration levels and
which can be biologically degraded without detrimental effect to the body of water
involved.
(d) Chemical Removal - For most soluble hazardous materials, chemical methods
of removal show the most promise. There are several possible chemical counter-
measures, all of which require further development before they can be operational.
These include:
(1) Addition of Chelating, Complexing, or Precipitating Agents - These
methods involve the addition of a secondary agent to react with the soluble hazar-
dous polluting substance to form an insoluble product which can be removed from the
watercourse by skimming, dredging or suction pumping. Before these methods can be
accepted, studies must be undertaken to assure that the chelating, complexing or
precipitating agents and the resulting compounds formed by reacting these agents
with the spilled pollutant are considerably less harmful to the water ecosystem
than the pollutant.
(2) Addition of Neutralizing Agents - These methods involve the addition
of acids or bases to neutralize the spilled material and render it harmless to the
environment. The use of neutralizing agents is obviously limited to only those
acidic and basic materials which are considerably less toxic than the spilled
chemical and which, upon reaction with the chemical, generate no deleterious secon-
dary products.
(3) Chemical Removal Using Chemisorption - Potentially, this technique
shows the most promise of any chemical removal method. For several years, adsorp-
tion of trace organics on activated carbon has been used in tertiary sewage or
potable water treatment. The principal limitation of this method is that it is
severely dependent on a significantly large, ready supply of carbon. Consequently,
carbon chemisorption techniques can not be readily utilized at the present time
unless the spill occurs at a location near to where a treatment facility already
exists.
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U. Current Status
It is clear from the above that adequate control, neutralization and treatment
techniques for countering spills of hazardous materials are practically non-existent,
These countermeasures for the most part require technology not presently available.
Nevertheless, it is considered that new and useful techniques can be developed by
intensive experimental programs on spill control and cleanup methods.
Inasmuch as the Water Quality Improvement Act of 1970^) requires the designa-
tion of appropriate methods and means of removal of spilled hazardous materials,
the Environmental Protection Agency's Division of Applied Science and Technology
initiated a number of programs for the development of methods to treat and control
spills of selected high priority hazardous materials. These programs cover a wide
range of countermeasures for: containing spills before they reach surface waters;
for containing contaminated water after a spill; and for decontaminating polluted
water areas to return the water to a restored condition of quality. Specifically,
some of the proposed countermeasures under investigation are:
(a) development of devices to contain spilled hazardous materials on land
by use of rapidly formed in place plastic dams or foamed dikes.
(b) development of foamed plastic devices for stopping leaks of hazardous
materials from ruptured containers both on land and underwater.
(c) development of methods to polymerize and remove spilled hazardous mater-
ials on land and to prevent percolation of the materials into the ground.
(d) development of rapidly deployable physical barriers which extend from
above the surface of the water to the bottom of the waterway for the purpose of
containing spilled hazardous materials in watercourses.
(e) development of a decontamination system using floatable mass transfer
media (e.g., ion exchange resins and carbon sorption media modified to result in
specific gravities less than 1) for: subsurface introduction into waterways;
treatment of contaminants; and collection of spent media at the water's surface.
(f) development of a continuous flow through thin film aerator to which
chemicals can be added to neutralize, oxidize, precipitate or adsorb spilled
hazardous materials from watercourses, and to develop a static sealed centrifuge
to remove gases, precipitates, carbon slurries, and other solids from the effluent
of the aerator device.
(g) development of a modular transportable treatment system incorporating
various unit processes such as neutralization, flocculation, precipitation, filtra-
tion and carbon adsorption, for the purpose of on-site removal and treatment of
spilled hazardous materials in waterways.
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V RESEARCH NEEDS
The Environmental Protection Agency will continue to place substantial emphasis
on research and development programs (in which contracts and grants will be awarded)
to develop new concepts for coping with the hazardous material spill problem. In
this regard, it is essential that the best available research capabilities be util-
ized to develop the technology required to protect the water ecosystem. Some of the
EPA's research needs in this area are briefly outlined below.
A. Prevention
Because of the chemical and physical nature of hazardous substances and the
inherent difficulty of their removal from watercourses,'. preventive techniques are
viewed as a primary means of mitigating damage to the aquatic environment. To de-
velop the technology to prevent spills, the need exists to define the critical areas
of maximum spill probability. For this purpose, potential high frequency spill
sources, such as production sites, terminal and storage facilities and the various
transportation modes, should be explored.
B. Reporting and Information System
To insure prompt response to a spill, there is a need for the development of a
spill reporting and information retrieval system. This system should have the cap-
ability of storing chemical, physical and biological data, past spill information
and control techniques for a continuously expanding library of high priority haz-
ardous materials. The system would rapidly communicate this information and data
during a spill incident so that the best possible countermeasure devices could be
dispatched to cope with the incident.
C. Detection, Identification and Monitoring
The rapid and effective deployment and use of hazardous material spill control
techniques requires the immediate knowledge of the identity and concentration of the
polluting substance, as well as the extent of the spill at any given time. Accord-
ingly, the need exists for the development of readily available field equipment and
devices to rapidly detect, characterize and monitor spilled contaminants in the
water environment.
D. Restoration and Damage Assessment
Severe damages to the aquatic environment may result from spills of hazardous
substances because of failure of preventive techniques or unavailability of ef-
fective, rapid countermeasures. Consequently, there is a need for the development
of restoration procedures, such as reseeding techniques, for rebuilding damaged
ecological systems. To fulfill this need, procedures should also be developed for
assessing the nature and extent of damage to the environment resulting from such
spills.
E. Fate and Effects
In order to comprehensively evaluate and assess the ecological damage result-
ing from hazardous chemical spills and to better identify the high priority
materials requiring more detailed prevention methodology, a study is needed to
determine the fate and long term effects of these materials on the environment.
In this respect, information is needed on the persistence of the materials and
their synergistic and antagonistic effects on watercourses.
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F. Ultimate Disposal
Methods to contain and/or treat spilled hazardous materials will result in
varying volumes and concentrations of liquids and sludges which must be disposed
of in such a manner as to prevent subsequent hazards to the environment. Need
exists, therefore, to review and evaluate existing disposal technology that may
be applicable for spill incidents and to develop new, more effective methods where
necessary.
VI REFERENCES
1. "Spill Prevention Techniques for Hazardous Polluting Substances", Arthur D.
Little, Inc., Report No. OHM 7102001, prepared under Contract 14-12-927 for
the Environmental Protection Agency, February 1971.
2. "Control of Spillage of Hazardous Polluting Substances", Battelle Memorial
Institute, Pacific Northwest Laboratories, Report No. 15090 FOZ, prepared
under Control 14-12-866 for the Federal Water (Duality Administration,
November 1970.
3. Public Law 91-224, 91st Congress, H. R. 4148, "Water Quality Improvement Act",
April 3, 1970.
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