440/9-75-005-b
FINAL REPORT
VOLUME H - TECHNICAL DOCUMENTATION
DETERMINATION OF HARMFUL QUANTITIES AND
RATES OF PENALTY FOR HAZARDOUS SUBSTANCES
5
W
\
LU
CD
JANUARY 1975
ENVIRONME3NTAL PROTECTION AGENCY • OFFICE OF WATER PLANNING AND STANDARDS
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EPA-440/9-75-005-b
FD L R r
VOLUME II - TECHNICAL DOCUMENTATION
DETERMINATION OF HARMFUL QUANTITIES AND
RATES OF PENALTY FOR HAZARDOUS SUBSTANCES
by
Gaynor W. Dawson
Michael W. Stradley
Alan J. Shuckrow
CONTRACT 68—01—2268
Prolact Officer
C. H h ‘11u eon
OCTOBER 1974
Prepared for
- - cEs CH
OFFICE OF WATER PLANNING AND STANDARDS
U. S. ENVIRONMENTAL PROTECTION AGENCY
WASHINGTON, D. C. 20460
For sale by the Superintendent of Documenta, U.S. Government Printing Office
Washington, D.C. 20402 - Price $10.10 per set 0(4 VoIs. Soki In sets only.
Stock Number 045-001-01028-1
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TABLE OF CONTENTS
I. INTRODUCTION
I I . SUI’4IVIARY . . . . . . . . . . .
GENERAL . .
THE RESOURCE VALUE METHODOLOGY . . . .
THE IMCO METHODOLOGY . . . . . .
THE UNIT OF MEASUREMENT METHODOLOGY .
THE DOHM METHODOLOGY . . . .
III. UNDERLYING CONCEPTS COMMON TO THE DEVELOP-
MENT OF ALL APPROACH METHODOLOGIES . .
GENERAL
THE PRACTICALITY OF IMPLEMENTION AND
ENFORCEMENT OF THE METHODOLOGIES . . .
USEOFPURECOMPOUNDS .... .
DESIGNATION OF UNITS OF MEASUREMENT .
SELECTION CRITERIA FOR ESTABLISHING
CRITICAL CONCENTRATIONS
Typeof Effect . . . . . . . . .
Magnitude of Effects . . . . . . . .
Duration of Effects . . . . . . . .
Receptor Species . . . . . . . .
Other Considerations . . . . . . . .
IV. THE RESOURCE VALUE METHODOLOGY . . . .
BRIEF . • • S
VALUETHRESHOLD .. . .. ...
SELECTION OF THE CRITICAL
VOLUME FORLAKES . . .........
SELECTION OF A CRITICAL
Page
• 11—1
• 11—7
• 11—7
• 11—7
• 11—8
• 11—8
• 11—9
• Il—li
• 1 1—11
• 1 1—11
• 11—12
• 11—12
• 11—14
• 11—20
• 11—22
• 11—23
11—28
11—29
• 11—37
• 11—37
• . 11—37
• • 11—42
VOLUME FOR ESTUARIES . . •
• . . . . . . • 11—46
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TABLE OF CONTENTS (Cont’d.)
SELECTION OF A CRITICAL
VOLUME FOR RIVERS
SELECTION OF CRITICAL VOLUME
FOR COASTAL WATERS
EXAMPLE HARMFUL QUANTITY
CALCULATIONS
INITIAL RATE OF PENALTY
ADJUSTMENT FACTOR .
Intrinsic Factors
Extrinsic Factors
Summary
DETERMINATION OF THE FINAL
RATE OF PENALTY
V. THE MODIFIED IMCO/GESAMP
METHODOLOGY
11—48
11—49
11—51
• . 0 • • • • • . . 11—52
11—52
11—52
• . . I I S I • S • 11—59
11—63
S S I •
• . . 11—63
• . . 11—67
IMCO/GESAMP REPORT ON THE IDENTIFICATION
OF NOXIOUS AND HAZARDOUS SUBSTANCES
General . .
The lMCOSystem .
Applicability of the IMCO System
to Determining Harmful Quantities
and Rates of Penalty for Hazardous
Material Spills
Modification of the IMCO System . .
THE IMCO METHODOLOGY FOR DETERMINING
HARMFUL QUANTITIES AND RATES OF PENALTY
Profiling and Categorization
of Hazardous Materials
Quantifying Differences Between
Hazard Categories and Physical/
Chemical Characteristics . • . . . •
Determining the Harmful Quantity . .
BRIEF 11—67
11—68
11—68
11—70
11—72
11—74
11—74
11—74
11—76
11—79
ii
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TABLE OF CONTENTS (Cont’d.)
Determining the Base
Rate of Penalty
Fine Determination
Sample Calculations
VI. THE UNIT OF MEASUREMENT METHODOLOGY
BRIEF
METHODOLOGY RATIONALE .
UNIT OF MEASUREMENT AND HARM-
FLIL QUANTITY DETERMINATION
COMPUTING THE BASE
RATE OF PENALTY
Fine Determination . .
SAMPLE CALCULATIONS
VII. DORM METHODOLOGY . . . .
BRIEF
HARMFUL QUANTITY DETERMINATION
StreainModel . •. .
Stream Quantity Determination
LakeModel . . . . . .
Estuarine Model
Water Quantity Determination
Ocean Model .
Harmful Quantity Calculation
Locational Factor . . .
RATE OF PENALTY
Cost of Prevention ; .
Stationary Sources . .
Non-Stationary Sources
• . . . 11—81
. • • . . 11—81
11—83
• . . . 11—87
11—94
• • . . • • . • 11—97
• . . . • . • . 11—99
11—99
• S • I I • • I 11—100
I • I 1—100
11—103
• S • I I 11—110
• . • . • • 11—113
11—113
• 11—116
• 11—120
• 11—120
• • • . . . 11—120
• • . • • • 11—122
• . • • • . 11—122
• • • . • . 11—124
11—87
• . I I • I I I 11—87
11—90
• 11—94
Application Factor . • . •
. . . . • . . . . 11—125
iii
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TABLE OF CONTENTS (Cont’d.)
Railroads • • 11—127
Trucking 11—128
Base Rate of Penalty 11-128
Adjustment Factor 11-129
Dispersion - Solubility Factor 11-129
Toxicity Factor . 11—130
Degradability Factor 11—133
iv
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LIST OF FIGURES
Number Page
1 11-1 RELATION BETWEEN LD 50 AND CRITICAL
CONCENTRATION BASED ON HUMAN INGESTION. . . . 11-17
POINTS PLOT ORAL LD 50 VALUE FOR RAT
VS CRITICAL CONCENTRATION BASED ON
AQUATIC TOXICITY • • . . . . 11—18
111-2 SURVIVAL OF R. heteromorpha IN
SOLUTION 11—24
111-3 ACCUMULATED PERCENTAGE OF REPORTED
FISH KILLS VERSUS DURATION 11-26
111-4 SELECTION OF PRIORITY ORDER FOR
RECEPTOR SPECIES 11-31
111-5 THE VARIATION IN AMMONIA LC 50 VALUES
WITH CHANGES IN pH AND ALKALINITY . . 1132
IV-1 FLOW DIAGRAM FOR RESOURCE VALUE
METHODOLOGY 11—38
IV-2 DECISION TREE FACING AGENT WHEN
HARMFUL QUANTITY IS SPILLED AND
THRESHOLD IS SET AT $10,000 11—41
IV-3 UNIT VALUES FOR A GIVEN VOLUME OF
LAKE WATER AS A FUNCTION OF OVERALL
SIZE 11—44
IV-4 PRESENT WORTH OF ESTUARINE SYSTEMS
AS A FUNCTION OF THEIR SIZE 11-47
IV-5 VALUATION CHARTS FOR ASSIGNING ResU
FACTORS TO WATERS OF UNKNOWN VALUE. . . . . . 11-61
V-i FLOW DIAGRAM FOR IMCO METHODOLOGY . . 11-69
VI-1 FLOW DIAGRAM FOR UNIT OF MEASURE-
MENT METHODOLOGY 11-88
VI-2 COMMON HAZARDOUS MATERIAL CONTAINERS. 11-91
Vu-i FLOW DIAGRAM FOR DOHM - COST OF
PREVENTION METHODOLOGY . . 11-101
V
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LIST OF FIGURES (Cont’d.)
VII-2 RELATIONSHIPS BETWEEN HARMFUL
QUANTITY, TIME OF PASSAGE AND
CRITICAL CONCENTRATION 11-104
VII-3 ACCUMULATED PERCENTAGE OF REPORTED
FISH KILLS VERSUS DURATION. . . . . . . . . . 11—106
VII-4 REPRESENTATIVE TIME-DOSE
MORTALITY CURVES . . . . . 11—108
VII-5 PERCENT OF TOTAL FLOW CONTAINED
IN STREAMS OF THE STATED MEDIAN
FLOWRATEORGREATER 11-112
VII-6 TWO DILUTION STREAM SYSTEM . . . . ii-ii7
VII-7 FRACTION OF TOTAL ESTUARINE
INFLOWS DERIVED FROM STREAMS
WITH THE STATED MEDIAN FLOW
OR GREATER 11—119
VII-8 RELATIVE CHANGE IN POTENTIAL SPILL
ZONE WHEN MATERIALS OF EQUAL SOLUBILITY
HAVE GREATLY DIFFERENT CRITICAL
CONCENTRATIONS . . . . 11—131
VII-9 RESPONSE OF TH} DISPERSION-SOLUBILITY
ADJUSTMENT TERM TO CHANGES IN THE
SOL/LC 50 RATIO. . 11—132
Vil-lO RESPONSE OF THE TOXICITY ADJUSTMENT
FACTOR TO CHANGES IN THE 500/LC 50 RATIO . . . 11-134
VIl-il RESPONSE OF THE DEGRADABILITY ADJUSTMENT
TERM TO VARIATION IN THE FRACTIONAL LOSS
CHARACTERISTIC. . . . . . . 11—135
vi
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LIST OF TABLES
Number Page
1 1 1-1 PRIORITY LISTING OF SPECIES FOR
SELECTION OF CRITICAL CONCENTRATIONS
IN ORDER OF PREFERENCE . . 11-30
IV-1 VALUATION OF FRESHWATERS IN U. S.
BY VARIOUS SOURCES...... 11—46
IV-2 SPECIFIC VALUES AND ASSOCIATED CRITICAL
VOLUME WITH A VALUE OF $5,000 FOR THE
FOUR BASIC WATER BODY TYPES. . . • 11-50
IV-3 IMPACT PERIODS ASSIGNED TO MATERIAL
CLASSIFICATIONS FOR USE IN DERIVING
THEAnf FACTOR. . 11—54
IV-4 PRESENT WORTH OF ANNUITY AND Anf FACTORS
ASSOCIATED WITH THE SELECTED IMPACT
DtJRATIONPERIODS 11—56
IV-5 RELATIVE Disp FACTORS FOR VARIOUS
WATERBODYTYPES..... .. 11—58
V-i IMCO CATEGORY CRITICAL CONCENTRATIONS. . . . 11-77
V-2 IMCO METHODOLOGY HARMFUL QUANTITIES. . . . . 11-80
VI-1 CALCULATION OF UNITS OF MEASUREMENT
AND HARMFUL QUANTITIES FOR IMCO
CATEGORIES . 11—93
VI-2 RECOMMENDED HARMFUL QUANTITIES . . . . . . . 11-94
VI-3 BASE RATE OF PENALTY 11-95
Vu-i THE RATIO OF 96 TO 6 HOUR LC 50 FOR
COMMON SPECIES EXPOSED TO DESIGNATED
HAZARDOUS SUBSTANCES 11—109
VII-2 HARMFUL QUANTITY EQUATIONS . . . 11-121
VII-3 EXAMPLE HARMFUL QUANTITY CALCULATIONS. . . . 11-121
VII-4 BASE PENALTY FOR VARIOUS SOURCES . 11-128
VII-5 EFFECT OF THE SUBSTANCE’S CHARAC-
TERISTICS UPON THE ADJUSTMENT FACTOR . . . . 11-136
vii
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LIST OF TABLES (Cont’d.)
VI1-6 EXAMPLE CALCULATIONS OF FINAL RATES OF
PENALTY FOR SPILLS IN FRESHWATER. . . . . . 11-138
viii
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This report was initiated by the Environmental Protection Agency
to gather additional information and to complete several con-
cepts developed by the technical staff of the Agency. This
report is one of the series dealing with hazardous materials
and the prevention and/or removal of spills of these materials
into or upon the navigable waters of the United SLates. The
rnet1 odoloc3ies were determined to be necessary to provide a
technical basis for the development of regulations under
Section 311 of Water Pollution Control Act as amended in 1972
(PL 92 - 500) . This :i:eport is a result of several man years of
work by the Government, industry, and the contractor. It
should be understood that the methodologies explained here may
be used in some modified form in regulations to he developed
and/or revised as appropriate to implement Section 311.
This document should be regarded as a technical reference docu-
ment which may be used as appropriate by this Agency and others
prri manly in the dove lopinent of the regulatory control program
for hazardous substance spills. The principal regulations for
which these methodologies were developed are required to be
promu 1 .gatcd under Section 311(h) (2) (B) (iv) and Section 311(b) (4)
which require that penalty rates for nonremovable hazardous
substances shall be prescribed and that quantities determined
to be harmful to public ha.1.Lh and welfare be identified. The
other regulations as rocjui.recl by Section 3.11 dealing with
hazardo s substancc.: 5 involve: the designation and dotermiflatlon
of removabilit : the determination of removal and mitigating
methods; the ermination of prcccduros and equipment for
spill p:ra.’ention; the determination of small facility spill
c aan’-up liabilities; the determination of nonharrnful quantities;
a ,id appropriate revision to the National Oil and Hazardous
Sub :Lence Polli 1:ion Contingency Plan. This information is
thought to be of use of assessing the environmental benefits
and potential economiC impacts in the development of regulations
dealing with me h ds for removal and mitigation of hazardous
substances and procedures and equipment for prevention of
hazardous substance spills from transportation, production and
use facilities.
At the time the project was conceived the Agency had participated
in international hazardous material control negotiations and
had gained considerable experience working with industry in the
production, distribution and use of materials which may be
designated as hazardous substances. Late in 1972 and early in
1973, it became the concern of this Agency that several alter-
native methods should be examined in detail to allow equitable
regulatory development. This concern was keyed to be pending
designation regulation which would list elements and compounds
as hazardous substances.
ix
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It is anticipated that the information that has been gathered
during this study which involved the National Hazardous Materials
Conference in San Francisco, August 1974, and the Regulation
Symposium in Washington, DC in October 1974 will be utilized
in part in the development of regulations to be published in
the Federal Register . Once the regulations are promulgated,
going through the process of Advance Notice of Rule Making,
Proposed Rule Making, and Final Promulgation, the program
will be implemented nationwide. This program implementation
is anticipated to be in conjunction with the United States
Coast Guard and to be implemented at the EPA Region and Coast
Guard District Level. It is further anticipated that areas
for the Administrator’s discretion in evaluating penalties may
be established as appropriate through EPA Guidelines and/or
Enforcement Regulations formulated by this Agency.
Particular thanks should be expressed to the primary authors
of this Report with special emphasis to acknowledge the coop-
eration provided by the chemical manufacturing industry, the
chemical transporting industry and others who supplied basic
information upon which this sti 3y is built. An individual
appreciation is expressed to Dr. Allen L. Jennings of the
Hazardous arid Toxic Substanccs Branch for his technical
participation and enthusiasm is seeing this job completed.
Others who helped in the review and editing for EPA included
Dr. Gregory Kew, Messrs. Robert Sanford, James Cating, and
Charles Gentry. It should be recognized that this project
was possible due to the foresight in planning, funding, and
the staff assistance of Messrs. Waiter Miguez, Robert Suzuki,
John Cox, and others of the Division of Oil and Special
Materials, without whose help this project would have been
impossible.
Dr. C. Hugh Thompson
Chief
Environmental Protection Agency
x
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I. INTRODUCTION
Pollution resulting from the spillage of oil and hazardous
materials has emerged as a major national problem. It is
presently estimated that some fifteen thousand such spills
occur annually in the naviqable waters of the United States, 1
of which more than three thousand involve non-oil materials. 2
These spills range in size from small quantities to millions of
gallons 3 and threaten many important waterways.
Recognizing this, the Congress has declared in Section
311 (b) (1) of the Federal Water Pollution Control Act
Amendments of 1972, that:
“.... it is the policy of the United States that there
should be no discharges of oil or hazardous substances
into or upon the navigable waters of the United States,
adjoining shorelines, or into or upon the waters of the
contiguous zone.”
Pursuant to this policy, Section 311 requires the formulation
of seven distinct regulations:
1) The designation of elements and compounds as
hazardous substances (Section 311 (b) (2) (A) I in
order to establish the list of materials other than
oil which will be subject to the remaining six
regulations;
2) The determination of removability of hazardous
substances [ Section 311(b) (2) (i)] in order to
group designated hazardous substances into removable
and non-removable categories for the purpose of
subsequent penalty determinations;
‘Thompson, C. H. and P. R. Heitzenrater. “The Environmental
Protection Agency’s Hazardous Material Spill Program,” pre-
sented at the American Institute of Chemical Engineers Work-
shop, Charleston, WV, October 27—29, 1971.
2 Wilder, I. and J. Lafornara. “Control of Hazardous Material
Spills in the Water Environment,” Water and Sewage Works ,
119: 1: 82, 1972.
3 Thompson C. H. and K. E. Biglane. “Oil and Hazardous
Materials--The Chemical Industry’s Liability or Asset?”,
presented to Chemical Markets Research Association in Chicago,
IL, February 24, 1971.
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3) The establishment of rates of penalty for SPillage
of hazardous substances [ Section 311 (b) (2) (B) (iv)]
in order to prescribe the penalties to be assessed for
spillage of non—removable hazardous substances;
4) The designation of harmful quantities [ Section 311
(b) (4)] in order to specify a quantity such that
spillage exceeding that amount must be reported by the
responsible agent to avoid crirflLnal prosecution for
failure to notify;
5) The establishment of small facilities liability
limits [ Section 311 (f) (2) 3 in order to provide
for the designation of certain small facilities
as low hazard potential spill sites eligible for
commensurately lower liability rates;
6) The specification of methods and procedures for
removing spilled hazardous substances [ Section
311(J) (1) (A)] in order to identify methods and
procedures to be employed in removing spilled
materials consistent with maritime safety and
navigation laws; and
7) The specification of spill prevention measures
[ Section 311(J) (1) (C)} in order to identify
procedures, methods, equipment, and other require-
ments pursuant to preventing discharges of
hazardous materials.
Each of these elements addresses a facet of the overall
hazardous substance spill problem in an attempt to stimulate
and encourage spill prevention measures. Indeed, prevention
has been clearly identified as the primary defense against
damages resulting from hazardous substance spills. It
is recognized, however, that spills can and will continue
to occur’ and therefore provision must be made to minimize
impacts in the event of these occurrences. This area of
regulation also serves as a part of the preventive posture
in that the financial resources required to remove hazardous
substances after spills constitute an economic incentive
to improve preventive measures.
Although none of the above regulations have been finalized,
many preliminary steps in the formulation process have
been taken. On major step has been the sponsorship of a
Dawson, G. W., A. 3. ShuckrOW and W. H. Swift. “Control of
Spillage of Hazardous polluting Substances,” U.S. Environmental
Protection Agency, FOZ 15090, October 1970.
11—2
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continuing interchange of ideas between responsible
officials in the Environmental Protection Agency (EPA) and
interested parties in the private sector in both a formal
and informal context. Exchanges have also been maintained
with other maritime nations through the Inter—Governmental
Maritime Consultative Organization (IMCO). Supportive
technical work has been provided by the EPA Office of
Research and Development and has been directed primarily
toward defining the scope of the problem, developing
means for spill prevention, and the removal of spilled
materials.
Two of the required regulations have been published
in the Federal Register 5 as advanced notices of proposed
rule making. These are the regulations dealing with the
designation of hazardous materials and the categorization
of those materials into removable and non-removable groupings.
The technical documentation required for two additional
regulations, those dealing with the designation of rates
of penalty and harmful quantities is the subject of the
research program reported herein. The objective of the
program was to develop at least three separate approaches
which could be used to derive harmful quantities and rates
of penalty for any given non—removable hazardous substance.
Four such methodologies were developed.
Each methodology is characterized by three distinct features:
1) the definition of substantial harm upon which the harmful
quantity is based, 2) the economic rationale for the base
rate of penalty 1 and 3) a means for varying rates of penalty
based on the physical—chemical and toxicological properties
of the material.
The first approach, the Resource Value Methodology, defines
substantial harm as $5,000 worth of environmental damage.
That is, harm is substantial when water with a recreational
and social value in excess of $5,000 is degraded to levels
impairing its value for those uses. Base rates of penalty
are set at the value of the damage potentially resulting
from a spill of a given material. Penalties are varied on
the basis of the probable duration of adverse impacts and
the physical-chemical properties which enhance or restrict
movement of the material in the environment.
The second approach, the IMCO Methodology, employs the
same basic definition of substantial harm and rationale for
5 Federal Register, Vol. 39, No. 164, Part IV, August 22, 1974.
11—3
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base rates of penalty as the Resource Value Methodology, but
focuses on four groups of hazardous materials rather than
individual materials. Each of the four categories is defined
in accordance with the Inter-Governmental Maritime Consult-
ative Organization (IMCO) system for hazardous cargo
classification. Toxicological data representative of the
category as a whole is employed to derive harmful quantities.
Penalties are varied over one order of magnitude through
use of adjustment factors designed to reflect the ability of
a material to spread in the environment and exert its hazard
potential.
The third approach offered, the Unit of Measurement Methodology,
defines substantial harm for an IMCO grouping of materials
indirectly through selection of a unit of measurement, suf—
ficiently large to be associated with probable harm in the
event of a spill. Similar quantities are selected for the
remaining groups of materials through comparison of their
relative toxicities. Penalties are varied on the basis of
the persistence, volatility, solubility, and specific
gravity of individual materials.
The final approach, the DOHM Methodolgy, defines substantial
harm in a statistical manner by developing an idealized plug
flow stream model and employing a flow rate selected from
statistical data on stream flow in the United States. The
base rate of penalty is equated to the estimated cost of
prevention (the expenditure per gallon spilled which would
have prevented the spill from occurring). Quantitative
operators are employed to vary the rate of penalty by a
factor of two as a function of the toxicity, degradability,
and toxicity-to-solubility ratio.
The development work reported here was undertaken with four
major boundary conditions specified. First, the resulting
methodologies were to cover only the technical aspects of
approaches to formulating the required regulations with the
structure provided by Section 311. No attempt was made
to modify the legislative mandate or explore policy and
enforcement options. Second, Congress has specified the use
of a civil penalty and, in so doing, has chosen a rationale
of encouraging spill prevention practices rather than one of
punitive damages. Indeed, it is acknowledged that a civil
penalty is best designed to deprive an offender of economic
advantage which noncompliance would otherwise have given him. 6
Hence, penalties must be substantial enough to counter
6 Grad, F. “A Treatise on Environmental Law,” §2.03,
pp. 2—1.66, 1973.
11—4
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existing economic incentives, but should not be excessively
high merely for the purposes of punishment.
Third, it was assumed that harmful quantities are best
defined in terms of mass or volume of a material spilled
rather than resulting concentration levels in receiving
waters. Since substantial harm in the aquatic environment
results from the presence of an excessive level of hazardous
material, the determination of harmful quantity in these
units requires the designation of both a critical volume
of water, and a critical concentration of material defined
as the threshold of harm. Each methodology offers a unique
approach to selecting the former while a common rationale
was employed to derive the latter. The details of these
selection processes are presented in the following
sections.
Finally, it was determined that while any single methodology
is composed of distinct parts, each part should be designed
as a discrete module that could stand alone or in combination
with modules developed for other approaches. Therefore,
while the results of the study are presented as four separate
approaches, a much broader field of options is available to
the regulatory agency through modular rearrangement of
individual approach facets such as the base rate of penalty
rationale, the adjustment mechanism for varying rates of
penalty, and locational variables designed for post-spill
penalty adjustment.
The text begins with a summary of the research effort. This
is followed by a discu gjo of underlying concepts common
to the development of approaches arid then the discussion of
each approach. Supporting work, input data on the physical-
chemical and toxicological properties of designated non-
removable hazardous substances, 5 and harmful quantities and
rates of penalty resulting from application of each methodology
to these substances are appended in a separately bound volume.
11—5
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REFERENCES
1. Thompson, C. H. and P. R. Heitzenrater. “The Environmental
Protection Agency’s Hazardous Material Spill Program,”
presented at the American Institute of Chemical Engineers
Workshop, Charleston, WV, October 27-29, 1971.
2. Wilder, I. and J. Lafornara. “Control of Hazardous
Material Spills in the Water Environment,”
Sewage Works , 119: 1: 82, 1972.
3. Thompson, C. H. and K. E. Biglane. “Oil and Hazardous
Materials—-The Chemical Industry’s Liability or Asset?”,
Chicago, IL, February 24, 1971.
4. Dawson, G. W., A. J. Shuckrow, and W. H. Swift. “Control
of Spillage of Hazardous Polluting Substances,” u.s.
Environmental Protection Agency, FOZ 15090, October 1970.
5. Federal Register, Vol. 39, No. 164, Part IV, August 22, 1974.
6. Grad, F. “A Treatise on nvironmenta1 Law,” §2.03,
pp. 2—166, 1973.
11—6
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II. SUMMARY
GENERAL
Section 311 of Public Law 92-500 requires among other things
the formulation of regulations designating specific elements
and compounds as hazardous substances and the subsequent
delineation of harmful quantities for these substances.
In addition, penalty rates are to be established for non-
removable hazardous substances to motivate greater efforts
in the area of spill prevention.
The objective of the subject study was to examine several of
the technical alternatives available for developing harmful
quantity and penalty rate regulations. A minimum of three
distinct methodologies was to be developed for defining
harmful quantities of designated hazardous substances and for
extablishing penalty rates.
For all methodologies, substances were characterized toxico-
logically on the basis of a critical concentration repre-
sentative of the hazard posed by the substance when spilled
into the aquatic environment. When possible, the selection
of critical concentrations was based on 96 hour LC5O data
for bluegill and fathead minnows. This course of action was
taken to ensure that potential harm resulting from release of
harmful quantities would be substantial and that data input
requirements would be tailored to available information.
Using the critical concentration as a starting point, four
individual methodologies were developed. Each has three
identifiable segments: 1) a mechanism for deriving harmful
quantities, 2) a rationale for the base rate of penalty, and
3) a scaling function to vary rates of penalty on the basis
of the physical, chemical, and toxicological properties of
individual materials. Additionally, two approaches offer
locational variables which further refine penalty assess-
ments based on the actual water uses and dispersive capacity
of the receiving body. Each of these segments has been
designed in modular fashion to allow the intermixing of
preferred segments to form cohesive hybrid methodologies.
THE RESOURCE VALUE METHODOLOGY
The first approach focuses on the value of water resources
potentially damaged by spills. A value of $10,000 is employed as
a threshold for defining substantial harm. Spilled quantities
capable of producing damage in excess of that amount are
defined as greater than harmful quantities. To quantify harm-
ful quantities thus derived, various types of water bodies
11—7
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are associated with per unit economic values based on those
uses affected by spills. A harmful quantity is thereby
set as the quantity capable of contaminating $5,000 worth
of environment to the critical concentration.
Rates of penalty are established which approximate the loss
of the water resource. Therefore, initial rates are $5,000
per harmful quantity. These rates are subsequently modified
by coefficients formulated to reflect persistence and
physical-chemical differences between materials which enhance
or inhibit movement in the environment. Locational variables
are also derived to account for resource values significantly
different than the base averages employed and for the variable
dispersive capacity of individual water bodies.
THE IMCO METHODOLOGY
The second approach illustrates the use of categorization by
grouping hazardous materials into four basic hazard categor-
ies. This diminishes the number of calculations required
in establishing harmful quantities and rates of penalty,
and lends itself to coded labeling of shipment containers for
more rapid recognition of hazard levels and regulatory
requirements.
The categorization scheme itself is one developed by the
joint Group of Experts on the Scientific Aspects of Marine
Pollution (GESAMP) under the aegis of the Inter-Governmental
Maritime Consultative Organization (IMCO).
Harmful quantities and rates of penalty are derived in the
same manner as under the Resource Value Methodology; however,
the critical concentration employed is that for the hazard
group rather than for each individual material. Rates of
penalty are adjusted with factors derived through a
Dc 1phi query intended to reflect the effect of a material’s
pt jsical/chemical properties on its ability to exert its full
hazard potential in the aquatic environment.
THE UNIT OF MEASUREMENT METHODOLOGY
The Unit of Measurement approach was designed to demonstrate
use of a unit of measurement independently derived. The
spectrum of liquid and dry shipping containers was reviewed
and divided at the break between bulk containers and individ-
ual package units. The smallest bulk unit is defined as the
harmful quantity for the least noxious hazardous materials
as classified in the IMCO groupings. Harmful quantities
for the remaining groups of materials are designated on the
basis of their toxicities relative to the least hazardous
I I —8
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grouping and then rounded to the nearest actual container
size.
Base rates of penalty are set at the statutory limit of
$1,000 per unit of measurement and modified downward through
the use of the IMCO Methodology adjustment factors for
individual materials.
THE DOHM METHODOLOGY
The DOHM approach focuses on the use of a plug flow model
for derivation of harmful quantities. The model employs a
statistically derived stream flow rate (95 percent of all
U.S. stream waters flow in streams of this median flow rate
or greater) to determine the quantity of a material required
to produce a plug, contaminated to critical concentration
which would take 96 hours to pass a stationary point.
An application factor is derived modifying the model to apply
to spills of short duration by compressing the plug.
Similarly estuarine systems were characterized by their
freshwater inflow. Harmful quantities for rivers were equated
to those for lakes while harmful quantities for coastal
waters were equated to those for estuaries.
Base rates of penalty are set equal to the cost of
reasonable spill prevention measures and thus should provide
the appropriate incentive for spill reduction. Rates
established are based on industrial cost estimates and
historical spill experience. Quantitative operators are
developed to vary rates of penalty up to twice the base
rate as a function of the dispersion potential, toxicity,
and degradability of individual hazardous materials as
required by Section 311. A means of modifying the plug
flow model to determine site specific harmful quantities
is also developed.
11—9
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III. UNDERLYING CONCEPTS COMMON TO THE DEVELOPMENT
OF ALL APPROACH METHODOLOGIES
GENERAL
Although the intent of the work reported herein has been the
development of diverse methodologies for defining harmful
quantities of hazardous materials and setting penalty rates,
many underlying concepts are common to all the developed method-
ologies. Therefore, it is important to describe the overall
framework within which methodologies were created before
presenting detailed discussions on the technical development
of each. In general, there are four broad areas which require
review: 1) the practicality of implementation and enforcement
of the methodologies; 2) the use of pure compound data and the
subsequent need for adjustment when spills involve solutions
or mixtures; 3) the manner of dealing with units of measurement;
and 4) the selection criteria employed for assigning critical
concentrations. Each of these considerations is discussed in
detail in the subsequent sections of this chapter.
THE PRACTICALITY OF IMPLEMENTATION AND
ENFORCEMENT OF THE METHODOLOGIES
Inherent in any regulatory mechanism is a tradeoff between the
ease of implementing and enforcing the regulation and the degree of
resolution that can be attained. That is, simplification of
the self-reporting and penalty assessment aspects of a regulation
necessarily results in a sacrifice in the degree of specificity
afforded individual circumstances and incidences. Thus, an
evaluation by the regulatory agency is required to balance the
benefits and costs of the two extremes so that a near optimal
blend of the two can be achieved. With respect to hazardous
material spills, the most easily enforced approach would be
the establishment of a single harmful quantity standard and a
single rate of p nalty. The approach with the greatest resolu-
tion would entail a complete post spill investigation of each
incident with subsequent establishment of an equitable penalty.
Neither option is appropriate at the present time. The first
would be inequitable in its treatment of discharges and would
not comply with the law since it ignores the statutory require-
ment to consider “...suc h times, locations, circumstances, and
conditions (which) will be harmful to the public health or
welfare of the United States” (Section 311(b)(4)]. The second
option is excessively burdensome in its demand for manpower, time,
and finances and would not comply with the law since harmful
quantities and rates of penalty must be developed a priori.
It has been concluded by the authors that the best approaches
‘I—li
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for setting harmful quantities and rates of penalty will be
those which favor ease of implementation and workability on
the part of both the regulating agency and those being regulated.
For example, the extremely large number of potentially threatened
waters in the United States have been condensed into four group-
ings based upon similar hydrodynaniic characteristics: lakes,
rivers, estuaries, and coastal zones.
USE OF PURE COMPOUNDS
Section 311(b) (2) (A) is very specific in its instruction to
designate elements and compounds as hazardous substances.
Additionally, most available data is pure compound oriented.
This has led to the development of methodologies for defining
harmful quantities and rates of penalty based on pure compound
characteristics. It is recognized, however, that spills are not
necessarily restricted to pure substances and all of the developed
methodologies can be applied to mixtures; some more readily than
others.
DESIGNATION OF UNITS OF MEASUREMENT
An integral part of the penalty structure outlined in Section 311
is the designation of a unit of measurement. Rates of penalty
are then bounded in the range of $lOO-$1000 per unit of measurement.
On the surface, this framework simplifies the task of selecting
a unit of measurement common to each hazardous substance. However,
for the vast majority of hazardous substances, there is no common
unit of measurement. Materials are shipped in a variety of con-
tainers which span a wide range of sizes. Moreover, no sizes
are standard with respect to stationary sources in that a plant
operator may construct reactors, storage tanks, and other vessels
of any desired size.
In the absence of an easily defined unit of measurement, it has
been suggested that one can be derived at least for transpor-
tation spill sources by determining the average shipment size,
or the average container size, based on annual shipping patterns.
It is apparent, however, that a unit of measurement thus derived
would be subject to yearly fluctuations as a result of changing
market patterns. More important, however, is the fact that for
most substances bulk shipments represent the vast majority of the
total volume shipped. In many cases, the ability to ship in
bulk and the size of bulk vessels is approved by Department of
Transportation regulations and related exemptions. Changes in
these policies could, therefore, abruptly alter the size and
sometimes the order of magnitude of a statistically derived unit
of measurement. Recent action concerning the bulk shipment of
parathion serves as a prime example of such an abrupt change.
Up until recently, guidelines restricted parathion shipments to
small individually packaged units. The statistically derived unit
11—12
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of measurement would have approximated a 208 liter (55 gallon)
barrel. An exemption has been instituted, however, which now
allows shipment in 45,420 liter (12,000 gallon) tank trucks.
Though the material remained the same throughout the period
of interest, the unit of measurement would have changed more
than two orders of magnitude in response to a single regulatory
policy shift. The rate of penalty would therefore drop in
a commensurate manner on a per unit volume basis, and hence
rates of penalty would become a function of transportation
regulations which may not consider the environmental implications
of hazardous substances. This would severely limit the ability
of the law to scale penalties on the basis of the “...toxicity,
degradability, and dispersal characteristics...” of a material.
Finally, the use of independently derived units of measurement
inhibits any attempt to scale rates of penalty to levels with
an economic significance, e.g., to exceed the cost of prevention
and thus provide strong economic incentive to take steps to
eliminate spills, or to repay society at a level commensurate
with the value of the damaged resource. This leaves to chance
the possibility that penalties will further the stated goals
of Section 311 and in some way strike a balance between the
costs to society of allowing spills to continue and those
associated with strict prevention.
This last point is considered very important. Indeed, three of
the four methodologies developed in this study attempt to define
an appropriate level for penalties and thereby set units of
measurement by a scaling procedure such that the penalties fall
in the $100-$1000/unit of measurement range. In order to clarify
the acceptability of such an approach within the framework of
Section 311, an interpretation was sought from Mr. Leon Billings,
Counsel for the Senate Committee on Public Works. His response 1
verified the validity of a dependent designation of units of
measurement. Consequently, for the purpose of all but the Unit
of Measurement Methodology, “units of measurement common to the
trade” have been interpreted as any unit of measurement which
one might employ in quoting prices or specifying quantities.
Thus, units of measurement are multiples of common English units
such as gallons, pounds, and tons.
For the most part, units of weight or mass were deemed the most
appropriate for use. This is primarily due to the fact that mass
units are common to all substances regardless of physical state,
while volume units are arbitrary in dealing with solids. It is
also common practice in the chemical industry to quote prices
1 personal communication, Mr. Leon Billings, Counsel for the
Senate Committee on Public Works, letter dated March 25, 1974.
11—13
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on a per—unit-of-weight basis. 2 Only the Unit of Measurement
Methodology differs from this standardization. This was
instituted to reflect the fact that shipment containers for
liquids are sized on a volume basis.
SELECTION CRITERIA FOR ESTABLISHING CRITICAL CONCENTRATIONS
There is no clear threshold such that spillage of more than a
given amount of a contaminant constitutes harm at all locations
and at all times while lesser amounts of the contaminant are
totally harmless at all locations and at all times. Rather, the
harm produced by the introduction of any pollutant to water is a
continuous function dependent upon receiving water characteristics
and measured in degrees of severity. Therefore, a key task in
determining harmful quantities pursuant to the legal mandate of
Section 311(b) (4) is the definition of when harm is severe enough
to be considered substantial. This requires an evaluation of
probabilistic damage or harm to representative water bodies,
recognizing that the potential for variations in water quality
and other factors to mitigate the effects of a spill limit the
practicality of assessing damage a priori in any but relative
terms.
Historically, the severity of harm resulting from the discharge
of materials to water has been associated with the resulting
concentration level of that material in the receiving body.
For the purposes of the work reported here, the concentration
where probable harm is considered substantial has been defined
as the critical concentration. Naturally, this critical con-
centration varies with the chemical of interest and with the
hazard type of concern. In order to establish critical concen-
trations for the development of the methodologies presented
here, it was necessary for the authors to limit the hazard types
and related concentrations that would be considered. Consequently,
it was assumed that the best value to be employed was the 96 hr
LC 50 for a median aquatic receptor. This assumption was based
on the considerations presented in the following discussion.
The damage a substance can produce when present in water is
closely associated with the uses of that segment of the water
body and the effects the substances produces which may alter
the water’s value for that use. Therefore, damage can be separated
into that associated with either withdrawal uses, or nonwith-
drawal uses. Common uses in the first category include potable
water supply, irrigation, and industrial water supply which may
be damaged by substances characterized by oral toxicity to humans
and livestock, taste and odor, phytotoxicity, corrosivity, and
2 0i1 Paint and Drug Reporter , September 1974.
11—14
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flammability. Uses common to the second category including
navigation, recreation, commercial and sport fishing, and
aesthetics are threatened by substances which are characterized
by toxicity to aquatic life; susceptibility to bioconcentration
or the ability to taint fish flesh; toxicity via skin absorption;
propensity to cause skin and eye irritation; exertion of biochemical
oxygen demand; biostimulation; and odor, color, or other properties
which lead to a reduction in amenities. The concentration levels
at which these effects become significant are therefore the
respective thresholds from which harmful quantities can be deter-
mined. While it is recognized that the final intended uses of
water are all important, the thresholds associated with each may
differ greatly for a single material, and hence one must be
selected as the critical concentration upon which regulation will
be based. That is, only a single framework can be employed for
establishing a set of consistent standards. Factors bearing on
the selection of a single framework include:
• The greater availability of data on levels of harm
for nonwithdrawl uses vs that available for with-
drawal uses (i.e., while aquatic toxicity data has
been published for many substances, acute human
toxicity and acute phytotoxicity information are
not available. The limited data available on
human and plant toxicity is directed to chronic
exposure);
• The higher degree of protection afforded withdrawal
uses as a result of various levels of pretreatment
and water quality monitoring such as water treatment
plants for municipal and industrial supplies;
• The fact that present civil law is better suited for
recovery of damages to withdrawl use waters than to
nonwithdrawal uses because of the greater ease of
demonstrating damages (e.g., damage to crops from
spills can be recovered directly by civil suit since
the injured party is easily identified. Similarly,
injuries resulting from consumption of poisoned
municipal water can be settled in court.* Analyses
to the aquatic environment are not so well protected
against because of difficulties in quantification
and identification of injured parties); and
• The added difficulty in assessing probable harm to
withdrawal uses a priori as a result of additional
probabilistic factors (e.g., location of intake,
degree of pretreatment).
*A case in point is a settlement issued in Mississippi when a
spill of sewage contaminated water withdrawn to raise minnows
commercially. Judgement allowed recovery of income lost during
the period of impact, $30,000.
3 Records of Court Proceedin9s, State of Mississippi.
11—15
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All of these points suggest the use of the nonwithdrawal frame-
work for setting standards. Further, the authors recognize that
harmful quantities are a self-reporting mechanism designed to
aid in the reporting of spills which might otherwise go undetected.
Spills impairing withdrawal uses are much more likely to be
reported in the absence of such a mechanism than are spills
impairing nonwithdrawal uses. For these reasons, the authors
conclude that the major candidates for critical concentrations
should be selected from the thresholds for substantial harm to
nonwithdrawal uses.
It is further postulated that harmful quantities based on aquatic
toxicity data will be lower than those derived from existing acute
oral toxicity data for mammals. To verify this, a scenario must
be developed to transform oral LD 50 values to acute aquatic con-
centrations. Existing drinking water limits are not appropriate,
since they are designed to protect against chronic ingestion of
toxins and do not reflect much higher exposures which can be
safely endured over short time periods such as those associated
with spill events. The scenario used here is based on a 70 Kg
man consuming 2.5 liters of water a day. Thus, a material with
a characteristic LD 50 of 5 mg/Kg body weight would be assigned
a threshold concentration of
5 mg/Kg x 70 Kg 2.5 liters = 140 mg/i (1.4 mg/i with a
100 fold safety factor applied)
The relation is disployed graphically in Figure Ill-i for a wide
range of LID 50 values. Points on graph illustrate the relation
between characteristic LID 50 and critical concentration based on
fish toxicity data for representative substances. Clearly, for
the vast majority (90 percent) of the randomly selected substances,
the critical concentration selected as a result of aquatic toxicity
is more restrictive than that for acute oral ingestion even after
application of a 100 fold safety factor. For the four
substances, the critical concentration derived from aquatic
toxicity is more restrictive than that for acute oral ingestion
with a 10 fold safety factor, but not a factor of 100. Con-
sequently, the aquatic nonwithdrawal use framework is the more
restrictive one within which to derive harmful quantities and
rates of penalty. Data employed in this analysis can be found
in Appendix A under the categories “Mammalian Toxicity” and
“Freshwater Critical Concentration.”
The effects which can impair nonwithdrawal uses differ greatly
in significance and in the levels at which resulting harm is
substantial. Color and odor may occur at low levels, but the
reduction in amenities which may result is typically brief in
duration and not easily defined as substantial harm in the
context of nonwithdrawal use. Toxicity via skin abosrption
11—16
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10, 000
.1 . 1.0 JO 100 1, OflO
FIGURE Ill-i.
RELATION BETWEEN LD 50 AND CRITICAL
CONCENTRATION BASED ON HUMAN INGESTION
1,000
100
10
1.0
0.1
.01
LD 50 In Mg/Kg Body Weight
10,000
11—17
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POINTS PLOT ORAL LD 50 VALUE FOR RAT VS CRITICAL
CONCENTRATION BASED ON AQUATIC TOXICITY
1. Acetaldehyde 21. Butyric Acid
2. Acetic Acid 22. Cadmium Chloride
3. Acrolein 23. Calcium Arsenate
4. Acrylonitrile 24. Calcium Cyanide
5. Aidrin 25. Calcium Hydroxide
6. Allyl Chloride 26. Catechol
7. Ammonium Bichromate 27. Chlorobenzene
8. Ammonium Formate 28. Chloroform
9. Arnmonium Molybdate 29. Cobaltous Chloride
10. Ammonium Persulfate 30. Coumaphos
11. Animoniuln Sulfamate 31. Cresol
12. Ammonium Sulfate 32. Cupric Chloride
13. Aniline 33. 2,4—D Acid
14. Antimony Pentachioride 34. Diazinon
15. Arsenic Pentoxide 35. Dicamba
16. Benzene 36. Dinitrophenol
17. Benzoic Acid 37. Disulfoton
18. Beryllium Chloride 38. Ethion
19. Butyl Acetate 39. Guthion
20. Butyl Amine 40. Methyl Parathion
11—18
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and propensity to cause skin and eye irritation can lead to
substantial harm; however, little quantitative data are avail-
able on the threshold levels at which these effects occur and,
hence, critical concentrations cannot be identified for most
substances. Further, these effects are usually the result of
direct contact of neat solutions rather than contact with aqueous
solution.
Bioconcentration is a hazard associated with a limited number of
relatively persistent materials. Damage resulting from biocon-
centration has been noted in only a few instances, and these
were related to continuous discharges. Because it would require
a heavy diet of aquatic life by a limited population in a
restricted area over a prolonged period to initiate harm through
bioaccumulation, the probability of this occurring as a result
of an acute spill is quite low. At the same time, there are
forces working to eliminate the materials from the affected
organisms. Bioconcentration is reversible if given sufficient
time.” The use of critical concentrations derived from such an
improbable event would at best be difficult to support and
therefore such an approach has not been used. Rather, biocon-
centrative properties are evaluated separately and used in adjusting
rates of penalty to provide added incentive against spillage of
these materials.
Exertion of biochemical oxygen demand (BOD) and biostimulation
are also associated largely with chronic or continuous discharges
but can conceivably result from acute spills. The critical BOD
level will largely be a function of the site of the spill since
dispersive characteristics, nutrients, normal dissolved oxygen
levels, and the ability of a water body to reaerate are key
factors in determining the development of DO related problems.
Similarly, acute stress arising from the release of biostimulants
will depend on the existing nutrient balance in the receiving
water and other site specific variables. Any attempt to fore-
cast harm for water bodies in general resulting from spills of
materials posing these hazards would necessarily be excessively
probabilistic in nature.
With respect to aquatic toxicity, data on the effects of various
pollutant levels to aquatic life have been collected for a variety
of substances and are reported in terms of the TLm or LC 50 . (The
median tolerance limit, TLm, is that concentration capable of
inducing a given effect in 50 percent of the sample population in
“Battelle Memorial Institute. “Program for the Management of
Hazardous Wastes,” U. S. Environmental Protection Agency, Contract
No. 68—01—0762, Vol. I, NTIS No. PB 233—630 and Vol. II, NTIS
No. PB 233—631, July 1973.
11—19
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the time specified. The LC 50 represents the median lethal concen-
tration.) At the same time, fish kills and other signs of distress
in the aquatic community have been the most frequently observed
environmental impact noted for chemical spills. 5 For these
reasons, toxicity to aquatic life has been selected as the best
hazard potential upon which to base critical concentrations.
Selection of aquatic toxicity as the major property of interest
is only a beginning. There are numerous parameters which must
be characterized before a standardized threshold level is defined.
Parameters of primary importance are type of effect, magnitude
of effect, time span, and species. A discussion of the options
available and the selection made for each parameter is given
below.
Type of Effect
Stephan and Mount 6 categorize potential hazardous effects on fish
into three groupings:
1. Direct effects - effects involving direct toxic action on the
receptor species.
2. Indirect effects - effects resulting from toxic action on
other species which in turn have an effect on the species
of concern, e.g., distructiOn of fish food organisms leaving
the fish species of concern with a diminished food supply.
3. Induced effects - effects which occur as a result of the
presence of a second toxic material which, when accompanied
by the first, becomes a hazard at normal non-hazardous levels,
e.g., synergism.
It is clear that direct toxic effects should be a major factor in
selecting critical concentrations. There is a great deal of
controversy, however, over similar use of indirect and induced
effect thresholds. Induced effects, since they require the
presence of a second toxic agent, are probabilistic in nature.
It is difficult, if not impossible, to predict the occurrence
of induced effects without focusing on a specific water at a
given time when water quality parameters are well defined. In
this respect, the use of induced effects would be similar to
attempting to use BOD or biostimulation for developing critical
concentrations. consequently, induced effects should not be a
primary concern.
5 Dawson, G. w., A. J. Shuckrow and W. H. Swift. “Control of
Spillage of Hazardous Polluting Substances,” FWPCA, F0215090,
October 1970.
6 Stephan, C. E. and D. I. Mount. “Use of Toxicity Tests with
Fish in Water Pollution Control,” Biological Methods for the
Assessment of Water Quality , ASTM, Philadelphia, PA, June 1973.
11—20
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The question of use of indirect effects from acute spills is not
so easily resolved for a number of reasons. Food fish organisms
may represent a variety of trophic levels including algae,
macrophytes, zooplankton, and macroinvertebrates. Individual
species’ sensitivities to toxic agents vary considerably such
that any one species may be harmed at considerably lower concen-
trations than those at which direct effects occur. This then
would suggest that the critical concentration should be the
lowest concentration at which direct effects on any organism
in the food chain occur. Clearly, this value will not be known
for most substances. Indeed, in many areas the identity of the
entire food web may not be established. Toxicity data for
species other than fish are scattered, and certainly have not
been generated systematically for the various food webs pertinent
to important aquatic ecosystems. Testing is complicated by
factors inherent in conducting bioassays and a lack of technique
standardization. The task would be simplified if representative
species were selected as indicator organisms. For instance,
Daphnia magna are often studied as the standard freshwater
macroinvertebrate. This simplification, however, works counter
to the rationale for being concerned with indirect effects, since
it is the weak link that determines the nature of the total resultant
harm, and not the most commonly studied link. The Daphnia them-
selves may be the victims of indirect effects.
There is an even deeper problem than the latter, however, and
that is the question of whether or not indirect effects will
lead to substantial harm when they result from a discrete dis-
charge. An acute change in species diversity may or may not
be noticeable in the lower forms of aquatic life. Since
hazardous material spills are relatively brief in duration, the
arguments against changes in species diversity of any kind used
in discussing continuous discharges may not be as valid.
Organisms in lower trophic levels often have relatively rapid
reproduction rates. Hence: the stress placed on the fish affected
is often one of having to alter feeding patterns for a brief
time only. In many ecosystems, alternative food sources may
be available. Consequently, predicting substantial harm based
on indirect effects to fish was not employed since it would have
been highly probabilistic in much the same manner as the use of
induced effects discussed earlier. Rather, the major source for
critical concentrations employed in this study was toxicity data
on direct effects to selected species of fish and shellfish with
direct recreational and/or commercial value; or data indicating
effects throughout an entire trophic level.
Similarly, lethality should be recognized as the toxic effect
of interest as opposed to sublethal responses. The death of an
important organism is clearly substantial harm, while sublethal
effects arising from an acute discharge may or may not be sub-
stantial, depending upon their level and duration. Whereas
11—21
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sublethal effects are of great concern in situations of continuous
discharge, in acute spill situations it is much more difficultt
to assess their transient importance. Additionally, sublethal
effects have been studied f or only a few substances and standard
testing procedures have not been developed. Data pertinent to
setting critical concentrations on the basis of sublethal effects
would be insufficient for most of the designated hazardous sub-
stances.
Magnitude of Effects
Having concluded that attention is best focused on direct
lethality to fish or shellfish, it is necessary to specify the
magnitude at which the effects become substantial. That is,
the critical concentration is defined only after one specifies the
percent of the affected population to which the substance is lethal.
This specification is necessitated by the fact that individuals
within a given species will differ in their ability to with-
stand toxic agents. Wuhrmann 1 characterizes the variance in toxic
response as one of normal distribution about a median response
level. This means that the death of the first fish in a given
population may not signal impending expiration for the remain-
ing individuals. In fact, significant factors on the order of
2-3 have been reported between the concentrations where first
and last death occurred in a fish population employed for
toxicological research. 8 While several points are generated
during the bioassay analysis (10—100 percent mortality levels)
only the 50 percent mortality level--LC 50 --is typically reported
in the literature. Indeed, the American Public Health Association
notes in Standard Methods 9 that the LC 50 is thE standard measure
of toxicity and must always be determined in bioassay work.
Therefore, reliance on anything other than the median toxic
limit would necessitate the use of data not frequently reported
in the open literature and would lack the value carried by an
accepted standard for measuring relative toxicity. Warren’ 0
discusses the fact that natural populations typically oscillate
as a result of interactive forces in the environment. It is
uncertain that contamination to the LC 0 or LC 20 levels would
produce fluctuations with any greater impact than these natural
oscillations whereas there is little doubt in the mind of most
7 Wuhrmann, K. “Concerning Some Principles of the Toxicology of
Fish,” Bull. Cent. Gelge Dacuiu. Eaux , No. 15, p. 49, 1952
(Fisheries Research Board of Canada Translation Series No. 243).
Personal communication, Dr. Thomas Thatcher, Aquatic Biologist,
Battelle—Northwest Laboratories, Richiand, WA, 1974.
9 Standard Methods for the Examination of Water and Wastewater ,
American Public Health Association, 12th ed., New York, 1969.
iDwarren, C. E. Biology and Water Pollution Control , W. B. Saun-
ders Company, Philadelphia, PA, 1971.
11—22
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individuals that a 50 percent loss would be substantial. It is
also important to note that laboratory bioassay results may not
be directly proportional to effects in the field. The potential
for variances in water quality and other factors to lessen the
effects of a spill reemphasizes the fact that damage cannot be
assessed in any but relative terms. Consequently, the best measure
of potential damage is a widely acceptable relative index of toxi-
city such as the LC 50 .
Duration of Effects
In addition to specifying the magnitude of effects, it is
necessary to specify the time period over which the effects are
exerted before a critical concentration can be selected. The
concentration at which the LC5O occurs varies with the time of
exposure. In fact, time-dose mortality curves resemble equilateral
hyperbolas when charted on arithmetical axes. 11 Consequently,
comparative data for individual compounds must be associated
with a set time of exposure before they have any meaning.
Investigators commonly use 24, 48, and 96—hour periods in
reporting bioassay results. The four—day, or 96—hour, period
has been widely accepted as the most meaningful test duration
when considering acute effects. Spragu&’’surnmarizes current
research results with the statement that acute toxicity to fish
generally occurs within the first 96-100 hours of exposure. The
96-hour LC5O can then be considered as the lower end of acute
effect concentrations. This becomes apparent from the time-dose
mortality relations referred to above. For most substances, the
96-hour LC 50 concentration occurs after the shoulder of the
curve and into tI .e zone where the curve approaches the asymptote
as illustrated in Figure 111-2. This property has led to the use
of 96 hour data to predict acceptable levels for chronic exposure
through introduction of a numerical application factor ranging
from 0.1 to 0.01.12
Application factors, however, are not considered appropriate for
use here. Section 311(b) (4) states that
“The President shall by regulation, to be issued as
soon as possible after the date of enactment of this
paragraph, determine for the purposes of this section,
those quantities of oil and any hazardous substance
the discharge of which, at such times, locations,
circumstances, and conditions, will be harmful to
the public health or welfare of the United States...”
Burdick, G. E. “A Graphical Method for Deriving Threshold
Values of Toxicity and the Equation of the Toxicity Curve,”
New York Fish and Game Journal , Vol. 4, No. 1, January 1957.
12 Sprague, J. B. “Measurement of Pollutant Toxicity to Fish,
I. Bioassay Methods for Acute Toxicity,” Water Research ,
Vol. 3, 1969.
11—23
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CONCENTRATION OF PHENOL IN PARTS PER MILLION BY WEIGHT
(LOG SCALE)
FIGURE 111-2. SURVIVAL OF R. heterornorpha IN PHENOL
SOLUTION (logarithmic time scale) 31
31 Abram, F. S. F l. “An Application of }Iarrnonics to
Fish Toxicology,” International J. Air/Water Pollu-
tion , Vol. 8, pp. 325—338, 1964.
100,000
60,000
40,000
20,000
10,000
6000
4000
2000
1000
600
400
200
1 00
60
40
20
w
-J
L)
f)
-J
L J
If )
I . —
- J
I-u
L)
1 10 100
11—24
-------
Application factors, on the other hand, modify levels known to
be harmful to “safe” levels. 13 Therefore, application factors
are applied when chronic exposure is anticipated and water
quality is to be maintained at a level safe to the exposed
population. As noted earlier, spills are acute events and there-
fore should not be dealt with in the same manner as continuous
discharges which pose a chronic threat. For a more detailed
discussion of acute vs chronic effects and application factors,
see Sprague. 12
Acute toxicity, 96—hour LC 50 , data appear very appropriate as a
baseline for use in studying the effects of hazardous material
spills. Spills are an acute phenomenon, and as such are well
represented by acute toxicity relationships. Since 96 hours
has been widely accepted as the threshold of acute exposure
times, 96 hour bioassays are most appropriate for work directed
to acute spills. Stephan and Mount 6 note that acute mortality
tests can indeed provide important information relative to the
probable effects relative to spills of chemical compounds.
Supporting data reflecting the distribution of spills by duration,
however, are not presently available.
Although spill duration data are not available, fish kill
duration data have been reported by the Department of the Interior
and the U. S. Environmental Protection Agency and can be utilized
as an estimate of the duration of fish exposure to the spill.
Two assumptions have been made in considering the applicability
of the data. The first is related tc the spill source. It IS
not known what fraction of the reported kills represent kills
due to non—spill related sources, e.g., runoff or leachate.
Therefore, it must be assumed that the distribution pattern
characteristic of all the reported kills is similar to that for
kills resulting from acute spills. The second assumption bears
on the relation between fish kill times and exposure times. It
is assumed that there is a relationship between deaths and
appearances of dead fish. Although the two time periods may be
out of phase with respect to each other, it is assumed that the
durations are essentially the same.
Figure 111-3 graphically displays the data available for the
duration of all pollution caused fish kills as reported in the
period 1960—1970. 1k 23 It can be observed from the plot that
13 water Quality Criteria , National Academy of Sciences, EPA-
R3-73-033, Environmental Protection Agency, (Advance Copy
1972)
“Pol1ution-Caused Fish Kills in 1960,” U. S. Department of
Health, Education, and Welfare, Public Health Service, 1960.
15 ”Pollution-Caused Fish Kills January-September 1961,” U. S.
Department of Health, Education, and welfare, Public Health
Service, November 1961.
11—25
-------
uJct)
L J
v)
LU
t- JuJ
i-I
LLJ
100
80
60
40
20
0
5 10 15 20 25
96 HR
DURATION OF FISH KILLS IN DAYS
ACCUMULATIVE PROBABILiTY OF FISH KILLS
LASTING EQUAL TO OR LESS THAN THE
INDICATED NUMBER OF DAYS
FIGURE 111—3.
ACCUMULATED PERCENTAGE OF REPORTED FISH KILLS VERSUS DURATION
-------
95 percent of the kills were of a duration of nine days or less
and that 85 percent of the fish kills had a duration of exposure
equal to or less than 96 hours. As illustrated in Figure 111—i,
there is little difference expected between the 96-hour TL5O
and the 216-hour TL 50 . Hence, the 96 hour exposure time can be
considered as a relative measure ot the longest period over
which most acute spills will pose a substantial threat to
aquatic life. This does not imply that all spills have a 96
hour duration. Rather, it contends that most will last 96 hours
or less. Therefore, basing harmful quantities on an exposure
period of 96 hours or less will be applicable to most spills.
One must also distinguish between the time duration for emptying
the vessel, and the time required for the spilled material
to pass the receptor. It is the latter which is pertinent to
the time span for which fish are exposed to a toxicant. The latter
is typically greater than the former since the dispersive forces
of the receiving water enlarge the contaminant plume with time.
Hence, a spill that occurs over a four—hour period may extend
to a longer duration plume as it travels downstream. As discussed
above, the present fish kill data suggest that 96 hours is a
reasonable upper boundary in most cases and it is to this time
span that attention is directed.
In conclusion, the prevalence of 96-hour LC5O data and the apparent
significance of 96-hour toxicity levels with respect to fish kill
plume time of passage indicate that the 96 hour LC 50 value for
materials will constitute the most representative critical concen-
tration. The test species, however, must still be designated to
assure comparable analysis for determination of harmful quantity
and rate of penalty for the various substances.
‘ 6 ”Pollution-CauSed Fish Kills in 1963,” U. S. Department of
Health, Education, and Welfare, Public Health Service, 1963.
17 ”Pollution-Caused Fish Kills in 1964,” U. S. Department of
Health, Education, and Welfare, Public Health Service, 1964.
18 ”Pollution-Caused Fish Kills in 1965,” U. S. Department of
Health, Education, and Welfare, Public Health Service, 1965.
L 9 1Fish Kills by Pollution in 1966,” U. S. Department of the
Interior, Federal Water Pollution Control Administration,
Washington, DC, 1966.
20 ”Pollution-CaUSed Fish Kills in 1967,” U. S. Department of
the Interior, Federal Water Pollution Control Administration,
Washington, DC, 1967.
21 ”pollution-Caused Fish Kills in 1968,” U. S. Department of
the Interior, Federal Water Pollution Control Administration,
Washington, DC, 1968.
2z 1969 Fish Kills Caused by Pollution,” Federal Water Quality
Administration, USGPO, Washington, DC, 1970.
23 ”Fish Kills Caused by Pollution in 1970,” U. S. Environmental
Protection Agency, USGPO, Washington, DC, 1972.
11—27
-------
Receptor Species
The selection of a given species for a priority listing of
preferred species is necessitated by the variance in sensitivity
displayed among species of the same trophic level, genus, or
family. Several investigators 2 27 have found 3—4 fold
differences in response between species when tested under identical
conditions with the same toxicant. Other data suggest order of
magnitude differences for some substances. 28 The relative order
of sensitivity between species also differs with the substance
tested. Wuhrmann 6 concludes that for each toxicant there is a
particular order of sensitivity for fish species. Therefore,
selection of a standard reference species can be a difficult
task.
Doudoroff, et al., 29 suggest that due to their abundance and relative
importance, freshwater species should be selected from the following
families. Centrarchidae (sunfishes, basses, crappies); Salmonidae
(trouts, chars, salmons); Cyprinidae (true minnows) excluding carp
and goldfish; and Catostomidae (suckers). The obvious choice for
any given situation would be the species common to the water body
of interest. Unfortunately, there is no species common to all
waters of the United States. Consequently, it was determined that
a median sensitive species should be employed to be representative
of the important species found in different environments throughout
the country.
Work to date on water quality criteria 12 has focused on the most
sensitive species as the receptor of concern, reflecting continuous
discharge and chronic exposure circumstances. This is not appro-
priate for spill regulations since harmful quantities are asso-
ciated with concentrations that “...will be harmful...” and the
presence of the most sensitive species and the significance of
that species in the affected waters are matters of conjecture.
Use of a median receptor leads to concentrations likely to produce
harm under median or most probable circumstances. The authors
2 Thatcher, T. 0. “The Comparative Lethal Toxicity of a Mixture
of Hard ABS Detergent Products to Eleven Species of Fishes,”
Air and Water Pollution International Journal , Vol. 10, 1966.
25 Pickering, Q. H. and C. Henderson. “The Acute Toxicity of
Some Heavy Metals to Different Species of Warm Water Fishes,”
Proceedings of the 19th Industrial Waste Conference, Purdue
University.
26 Bunting, D. L., II. “The Relative Resistances of Seventeen
Species of Fish to Petroleum Refinery Effluents and a Com-
parison of Some Possible Methods of Ranking Resistances,”
Thesis submitted at Oklahoma State University, August 1963.
27 Katz, M. and G. G. Chadwick. “The Toxicity of an Endrin For-
mulation to Some Pacific Northwest Fishes,” Robert A. Taft
Sanitary Engineering Center, Public Health Service.
11—28
-------
believe that this approach is better suited to the intent of the
law. This does not imply that water quality can be allowed to
slip to the levels associated with median receptor data. Rather,
it implies that in a spill situation contamination can reach
these levels before harm is likely.
With this in mind, bioassay data from McKee and Wolfe 28 were reviewed
to establish a priority list of freshwater species. Input data
for critical concentrations can then be selected giving preference
to the high priority species. These rankings are presented in
order of preference in Table 111-1. On the basis of this review,
Lepomis macrochirus (bluegill sunfish) was selected as the
priority freshwater species. These members of the Centrachidae
family typically display a median level of sensitivity. They
are widespread throughout the United States and are important
both for their recreational fishing value and as a food source
for larger, predatory sport fishes. Bluegills are easily kept
and reared and therefore are commonly used in laboratory work.
Consequently, bioassay data on this species are prevalent. Lower
priority species were ranked according to their prevalence in the
United States, and the availability of bioassay data. When only
limited data were available, acute toxicity levels for other
species were accepted. Selection of the order of preference
following bluegill is illustrated in Figure 111-4.
Fewer options are available when selecting critical concentrations
for marine waters.. Bioassay data on marine organisms are quite
limited. Oysters and other economically important species are
given top priority for marine waters. Abundance and importance
in estuarine systems are the primary criteria here rather than
sensitivity since a lack of data does not permit selection of a
median sensitive receptor.
Other Considerations
It is known that critical concentrations may also change with
other parameters such as temperature, pH, dissolved oxygen (DO),
and general water quality conditions. 29 Therefore, an attempt
has been made tc select bioassay data obtained under similar
conditions to ensure comparability. Selection is necessary
because water quality varies considerably among water bodies
in the United States and investigators often employ different
test conditions to match those of interest, or do not report
test conditions at all.
28 McKee, J. E. and H. W. Wolf. “Water Quality Criteria,” U. S.
Public Health Service/HEW, The Resources Agency of California,
State Water Resources Control Board, Publication 3-A, April 1971.
29 Doudoroff, P., et al. “ io-Assay Methods for the Evaluation of
Acute Toxicity of Industrial Wastes to Fish,” Sewage and
Industrial Wastes , Vol. 23, No. 11, November 1951.
11—29
-------
TABLE 111—1
PRIORITY LISTING OF SPECIES FOR SELECTION
OF CRITICAL CONCENTRATIONS IN ORDER OF PREFERENCE
Freshwater Species
Lepomis macrochirus (Bluegill)
(Other Varieties of Sunfish)
Lepomis (Pumpkinseed, Orange spotted, etc.)
Pimephales promelas (Fathead minnow)
Micropterus (Bass)
Ictalurus (Catfish)
Gambusia affinis (Mosquitofish)
(Other Important Species)
Morone saxatilis (Striped bass)
Salmo or Salvelinus (Trout)
Gasterosteus aculeatus (Threespine stickieback)
Carassius auratus (Goldfish)
Lebistes reticulatus (Guppy)
Oncorhyncus (Salmon)
Saltwater Species
Crassostrea virginica or Ostrea spp (Oysters)
Mercenia mercenia or Mya spp (Clams)
Peneaus (Shrimp)
Callinectes or Carcinus (Crabs)
Fundulus (Killifish)
Cyprinodon variegatus (Sheepshead minnows)
(Other Important Species)
Morone saxatilis (Striped bass)
The effect of variations in test conditions differs with the
substance of interest. For most industrial organic compounds
potential differences can arise from variations in temperature,
turbidity, and DO among other things. Wuhrinann 6 reports an
increase in median time to the LC 50 concentration of 20 to 50
minutes when DO changed from 4 to 8 ppm, respectively, for trout
exposed to cresol. For inorganic materials such as cyanide and
ammonia, pH and alkalinity can be especially important. Figure
111-5 illustrates the change in the LC 50 value to trout for
ammonia with variations in pH and alkalinity as summarized by
Sprague. 30 With heavy metals, dissolved solids, hardness,
30 Sprague, J. B. “Measurement of Pollutant Toxicity to Fish,
II. Utilizing and Applying Bioassay Results,” Water Research ,
Vol. 4, 1970.
11—30
-------
organic chelates and complexants, and pH become extremely
important because of the potential precipitation and subsequent
removal from solution of the toxic agent. In studies with
fathead minnows, Pickering and Henderson 23 found of water TLm
values for copper, cadmium, zinc and other metals from 50 to
100 times as great as those for hard water. Because the
variations in water quality are site specific, a middle ground
was necessary to indicate when the potential harm would be
substantial for most natural waters. This was achieved by
establishing a set of preferences whenever multiple data points
were available for use. When data were available on species
with similar sensitivity, highest priority was given to test
results in waters similar to conditions existing in most natural
waters. The pH range favored was 6.5—8.0 while hard water was
given priority over soft water. In most cases, no other specifi-
cations were necessary since use of the 96-hour TLm for bluegill
or fathead minnows severely limited the number of alternative
data points.
iiq
r4
‘.1
0
Low
Sen si ti vi ty
Magiia
FIGURE 111—4.
SELECTION OF PRIORITY ORDER FOR RECEPTOR SPECIES
Blu
Mo sq
Shiners
B
I sh
Stick Leback
T r u t
S
Low Median RLceptor High
11—31
-------
pH VALUE
FIGURE 111-5.
THE VARIATION IN AMMONIA LC VALUES
WITH CHANGES IN pH AND ALKA 2 NITY25
(The nunibers associated with each
of the curves are alkalinity expressed
as mg/9 CaCO 3 )
400
300
200
1 50
1 00
80
60
50
40
30
20
15
10
5
v-)
cL
U .-
Q
-J
UJ
-4
-4
6.5
7.0
7.5 8.0
8.5
9.0
11—32
-------
REFERENCES
1. Personal communication, Mr. Leon Billings, Counsel for the
Senate Committee on Public Works, letter dated March 25, 1974.
2. Oil Paint and Drug Reporter , September 1974.
3. Records of Court Proceedings, State of Mississippi.
4. Battelle Memorial Institute. “Program for the Management of
Hazardous Wastes,” U. S. Environmental Protection Agency,
Contract No. 68-01-0762, Vol. I, NTIS No. PB 233-630 and
Vol. II, NTIS No. PB 233—631, July 1973.
5. Dawson, G. W., A. J. Shuckrow and W. H. Swift. “Control
of Spillage of Hazardous Polluting Substances,” FWPCA,
F0215090, October 1970.
6. Stephan, C. E. and D. I. Mount. “Use of Toxicity Tests
with Fish in Water Pollution Control,” Biological Methods
for the Assessment of Water Quality , ASTM, Philadelphia,
PA, June 1973.
7. Wuhrmann, K. “Concerning Some Principles of the Toxicology
of Fish,” Bull. Cent. Gelge Dacum . Eaux, No. 15, p. 49, 1952
(Fisheries Research Board of Canada Translation Series No. 243).
8. Personal communication, Dr. Thomas Thatcher, Aquatic Biologist,
Battelle—Northwest Laboratories, 1974.
9. Standard Methods for the Examination of Water and Wastewater ,
American Public Health Association, 12th ed., New York, 1969.
10. Warren, C. E. Biology and Water Pollution Control , W. B. Saunders
Company, Philadelphia, PA, 1971.
11. Burdick, G. E. “A Graphical Method for Deriving Threshold
Values of Toxicity and the Equation of the Toxicity Curve,”
New York Fish and Game Journal , Vol. 4, No. 1, January 1957.
12. Sprague, J. B. “Measurement of Pollutant Toxicity to Fish,
I. Bioassay Methods for Acute Toxicity,” Water Research ,
Vol. 3, 1969.
13. Water Quality Criteria , National Adademy of Sciences, EPA-
R3-73-033, Environmental Protection Agency, (Advance Copy
1972).
11—33
-------
14. “pollution-Caused Fish Kills in 1960,” U. S. Department of
Health, Education, and Welfare, Public Health Service,
Washington, DC, 1960.
15. “pollution-Caused Fish Kills January—September 1961,” U. S.
Department of Health, Education, and Welfare, Public Health
Service, Washington, DC, November 1961.
16. “Pollution-Caused Fish Kills in 1963,” U. S. Department of
Health, Education, and Welfare, Public Health Service,
Washington, DC, 1963.
17. “Pollution-Caused Fish Kills in 1964,” U. S. Department of
Health, Education, and Welfare, Public Health Service,
Washington, DC, 1964.
18. “Pollution-Caused Fish Kills in 1965,” U. S. Department of
the Interior, Federal Water Pollution Control Administration,
Washington, DC, 1965.
19. “Fish Kills by Pollution in 1966,” U. S. Department of the
Interior, Federal Water Pollution Control Administration,
Washington, DC, 1966.
20. “Pollution-Caused Fish Kills in 1967,” U. S. Department of
the Interior, Federal Water Pollution Control Administration,
Washington, DC, 1967.
21. “Pollution-Caused Fish Kills in 1968,” U. S. Department of
the Interior, Federal Water Pollution Control Administration
Washington, DC, 1968.
22. “1969 Fish Kills Caused by Pollution,” Federal Water Quality
Administration, USGPO, Washington, DC, 1970.
23. “Fish Kills Caused by Pollution in 1970,” U. S. Environmental
Prcte.ction Agency, USGPO, Washington, DC, 1972.
24. Thatcher, T. 0. “The Comparative Lethal Toxicity of a
Mixture of Hard ABS Detergent Products to Eleven Species
of Fishes,” Air and Water Pollution International Journal ,
Vol. 10, 1966.
25. Thatcher, Q. H. and C. Henderson. “The Acute Toxicity of
Some Heavy Metals to Different Species of Warm Water Fishes,”
Proceedings of the 19th Industrial Waste Conference, Purdue
University.
26. Bunting, D. L., II. “The Relative Resistances of Seventeen
Species of Fish to Petroleum Refinery Effluents and a Com-
parison of Some Possible Methods of Ranking Resistances,”
Thesis submitted at Oklahoma State University, August 1963.
11—34
-------
27. Katz, M. and G. G. Chadwick. “The Toxicity of an Endrin
Formulation to Some Pacific Northwest Fishes,” Robert A.
Taft Sanitary Engineering Center, Public Health Service.
28. McKee, J. E. and H. W. Wolf. “Water Quality Criteria,”
U. S. Public Health Service/HEW, The Resource Agency
of California, State Water Resources Control Board,
Publication 3-A, April 1971.
29. Doudoroff, P., et al. “Bio—Assay Methods for the Evaluation
of Acute Toxicity of Industrial Wastes to Fish,” Sewage
and Industrial Wastes , Vol. 23, No. 11, November 1951.
30. Sprague, J. B. “Measurement of Pollutant Toxicity to Fish,
II. Utilizing and Applying Bioassay Results,” Water Research ,
Vol. 4, 1970.
31. Abram, F. S. H. “An Application of Harmonics to Fish Toxi-
cology,” International J. Air/Water Pollution , Vol. 8,
pp. 325—338, 1964.
11—35
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IV. THE RESOURCE VALUE METHODOLOGY
BRIEF
The methodology developed in the following discussion directs
attention to the economic value of environmental resources and
their potential loss as a result of the spillage of hazardous
materials. Harm is defined as a threshold dollar value such
that damage ir. excess of that amount is considered substantial.
The threshold itself is selected through a decision analysis
process with the intent of keeping the threshold in a reasonable
range without encouraging the discharger to gamble by failing
to report spills of quantities equal to or greater than the
harmful quantity.
Rates of penalty are derived to be commensurate with the value
of resources damaged. This provides for the internalization
of the costs to society of individual spills. Whereas past
spill site-specific damage assessment studies generally are
deemed unnecessarily expensive, adjustment factors are developed
which may be used to modify penalties on the basis of key
environmental parameters in the area of the spill. The infor-
mation flow required for the Resource Value Methodology is
illustrated in Figure IV-l.
VALUE THRESHOLD
The Resource Value Methodology approach was designed to directly
define a threshold at which harm becomes substantial. Implicit
in the selection of a harmful quantity is the assumption that
some given amount of damage can be viewed as too small to
warrant reporting to, and followup action by, the federal govern-
ment. This implies that there is some amount of harm that
society is willing to accept. Potential harm in excess of that
amount is substantial and therefore should be reported.
Two alternative methods fcr selecting the dividing line between
acceptable and substantial harm were examined in this work:
1) designation of some minimum volume of water for which potential
contamination is deemed significant, and 2) selection of a damage
value level which, if exceeded, defines substantial harm. The
former approach proved to be fruitless.
Neither legal precedence nor practical divisions, such as those
employed for stocking fish and game, were found to provide
sufficient uniformity to be of use. For instance, the Bureau
of Sports Fisheries and Wildlife, Department of the Interior.
typically will not plant lakes of a size less than 202 surface
hectares (500 surface acres). Similarly, the Environmental
11—37
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SELECT A DOLLAR
VALUE THRESHOLD
- ($10 000)
POST SPILL EVALUATION
OF RECEIVING WATER
CHARACTERISTICS (rk ext)
DETERMINE PRESENT
WORTH OF WATER
BODY TYPES (PW)
I
JDERIVE BASE RATES OF
‘1 (ROFPB)=(R OFP 0 )x
4
PENALTY
(rk int)
DERIVE FINAL RATES OF
PENALTY (ROF
(R OFPF)=(R OFPB)X
(rk ext)
FIGURE IV-1.
FLOW DIAGRAM FOR RESOURCE VALUE METHODOLOGY
3
DERIVE HARMFUL
QUANTITY
(HQ = ( 10,000 ) x (cc)
PW
CHARACTER I ZE MATER I ALS
BY PHYSICAL-CHEMICAL
PROPERTIES (rk int) AND
CRITICAL CONCENTRATION (cc)
‘I
DERIVE RATES OF
PENALTY R OF P 0 =
($10,0 0 0IHQ)
11—38
-------
Protection Agency lake rehabilitation program will not direct
efforts to lakes with less than 40 surface hectares (100 surface
acres).’ Some state agencies, on the other hand, maintain that
they will plant any body of water with recreation potential
regardless of size. Hence, the water body size becomes a function
of the species to be planted and the location where planting is
anticipated.
Due to the lack of uniformity among practices and the absence of
definition of some critical volume of water in legal precedence,
this approach was deemed unsatisfactory. The selection of any
single threshold would be arbitrary and, hence, subject to a
great deal of criticism. Economic thresholds, however, were
found to hold greater promise.
The economic threshold approach strives to establish a damage
value level which, when exceeded, represents a significant
enough potential loss to society that reporting and subsequent
federal action are warranted. There is precedence for such an
approach in previous regulations. Section 20.403 of Title 10
of the Code of Federal Regulations calls for notification of
incidents involving radioactive materials when damage to
property is in excess of $1000. Similarly, the Department of
Transportation requires reporting on all incidents involving
hazardous materials where property damage exceeds $50,000.
Section 311 of the Federal Water Pollution Control Act Amend-
ments of 1972 includes several economic values which appear
to be considered significant in the eyes of Congress. Monetary
amounts specified in Section 311 range from $500 to $5,000,000.
Congress has set $10,000 (and a one year jail sentence) as the
maximum criminal penalty for failure to report a spill of a
hazardous substance in excess of the harmful quantity. If the
rate of penalty for spillage is to be based on the value of
potential damage to the environment and the harmful quantity is
selected from a maximum acceptable damage level, then reporting
a spill of exactly a harmful quantity will automatically entail
a fine equivalent to the threshold selected and up to an
additional $5000 for spilling an amount in excess of the harmful
quantity [ Section 311(b) (6) 1. This suggests that the threshold
should not exceed $10,000. The reason for this is that at the
margin (i.e., when just a harmful quantity is spilled) the
responsible agent will weigh the merits of reporting the spill
and not reporting based on the penalties involved. If reporting
will obligate a spiller to a fine in excess of $10,000, he may
be willing to take the risk of not reporting, thus becoming
liable for both the civil penalty and the $10,000 criminal
penalty. The non—removable penalty will always be assessed. The
‘personal communication, Thomas Maloney, EPA/NERC, Corvallis,
OR, February 13, 1974.
11—39
-------
$5,000 harmful quantity penalty, however, can vary from 0 up to
$5000 and thus may not be assessed at all. On the other hand,
if the fine is less than or equal to $10,000, he is more likely
to report the spill and thus bring about the desired result.
Setting the damage threshold no higher than $10,000 should achieve
the latter result since the difference between a criminal and a
civil penalty and the possibility of imprisonment favor reporting
the spill.
When spills significantly exceed the harmful quantity, the
likelihood of their going unnoticed diminishes rapidly, and the
responsible agent is clearly motivated to report. Thus, setting
the damage threshold level no higher than $10,000 should provide
adequate incentive for reporting all spills of harmful quantities or
more. The tradeoff analysis described above is presented in a
decision tree form in Figure IV-2. Assuming no harmful quantity
penalty is assessed, reporting would cost the spiller $10,000,
while failure to report would have an average cost of $20,000 x (m)
in the long run, where m is the probability of the spill being
detected. Clearly, if m is 0.5 or greater, a report should be
filed. The additional threat of imprisonment reduces the level
of m necessary for reaching the equi—cost point. Assuming the
maximum harmful quantity spill penalty of $5000 is also assessed,
the equi-cost probability, m, rises to 0.6. Therefore, the
potential of an additional $0—$5000 penalty for reporting the
spill varies the equi-cost probability from 0.5 to 0.6 if the
$10,000 threshold is not exceeded. Since harmful quantities are
to be selected such that a high probability of damage exists,
it is reasonable to expect that m will exceed this equi—cost
range (0.5-0.6). That is, spillage of a harmful quantity
should cause sufficient harm to be readily observed, and
third party detection is likely to occur.
As the quantity spilled increases, m rapidly approaches one.
At the same time, the cost of not reporting and being caught
always exceeds the cost of reporting by $10,000. Hence, reporting
shoulL continue to be the alternative of least cost.
It is clear that without a quantitative estimate of the probability
m, the optimal level for the threshold cannot be selected. The
use of $10,000, however, appears to be sufficient to gain the
desired end. At the same time, there is reason to believe that
$10,000 should be considered as substantial, since Congress has
selected that level as the maximum for criminal penalties which,
by definition, are established to punish undesirable activity. 2
Therefore, the threshold should not exceed $10,000. It could,
however, be set lower. Congress has suggested in Section 311(b) (2)
(B) (iii) (aa) that amounts as little as $500-$5000 may be adequate
2 Grad, F. A Treatise on Environmental Law , §2.03, 2-166, 1973.
11—40
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SPILL UNDETECTED -COST = 0
y
NO REPORT MA DE/
FIGURE IV-2.
SPILL DETECTED -COST =
$10,000 CIVIL PENALTY
$10,000 CRIMINAL PENALTY
1 YR IMPRISONMENT
0-$5,000 CIVIL PENALTY
(FOR SPILL IN EXCESS
OF HQ)
$10,000 CIVIL PENALTY
0-$5, 000 CIVIL PENALTY
(FOR SPILL IN EXCESS
OF HQ)
REPORT MADE - COST =
DECISION TREE FACING AGENT WHEN HARMFUL QUANTITY
IS SPILLED AND THRESHOLD IS SET AT $10,000
SPILL OCCURS
H
H
-------
penalties on a per spill basis. The U. S. Coast Guard has also
been given the authority to assign penalties of up to $5000 on
a per spill basis. Consequently, one can assume that these
levels would be considered substantial within the context of
the law. These levels are low, however, when compared to
potential costs for responding to reports and enacting enforce-
ment. Indeed, response costs are likely to exceed the $2,000
per spill estimated expenditures for enforcing the present oil
spill regulations. 3 It would seem irrational to report spills
with damage levels below the cost of processing the report
itself. Therefore, $2,000-$l0,000 appears to be the most
reasonable range for a threshold value within the present frame-
work.
The harmful quantity penalty (up to $5000) directed by the Coast
Guard, can play an important role here. If the value threshold
is set at the same $5000 level, then a spill of a harmful quantity
will lead to an option baserrate of penalty of $5,000. This would
equal the maximum penalty for a spill of a harmful quantity pre-
scribed by Congress. Subsequent adjustment factors would scale
this down, but in essence, Congressional intent would be met, in
that the penalty for a spill of a harmful quantity would not
exceed $5000. Further, since $2000 may be a low estimate of the
cost of responding to spills, this penalty level would be likely
to represent values in excess of costs for response. Finally,
$5,000 falls between the desired $2000 to $10,000 range and
therefore satisfies all considerations. For the above reasons,
$5,000 has been selected as the dollar threshold distinguishing
the point at which potential damage becomes substantial.
SELECTION OF THE CRITICAL VOLUME FOR LAKES
The selection of an economic damage level threshold in the range
required to provide incentive for reporting still requires the
association of dollar values with quantities of water (i.e.,
cubic meters of lake water), so that a critical volume can be
associated with the $5000 level. This is necessary since
substantial harm is defined in terms of concentration and harm-
ful quantities are to specified in units of mass. Once a
critical volume has been established, one can convert between
the two sets of units. In order to provide such an association,
data were collected on the size and value of various water bodies
throughout the country. Valuation processes included bond levels
approved for restoring lakes, industrial development, income
foregone to preserve aesthetic qualities, purchase price, and
the present worth of annual recreation and commercial based
income. It is apparent, from the data, that a given volume of
natural water is subject to varying marginal costs or values as are
3 personal communication, Dr. A. L. Jennings, EPA/Division of Oil
and Hazardous Materials, Washington, DC, July 24, 1974.
11—42
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most economic goods; that is, as a lake becomes larger, the
incremental value of an additional unit volume of water becomes
smaller.
When the freshwater data were plotted on a scatter diagram, the
points demonstrated too great a spread to form a single relation.
Consequently, the individual points were segregated according to
the valuation method employed to obtain them. It is clear that most
valuation procedures establish a relatively sn oth relation
illustrating diminishing marginal values with increasing size.
The curves also form an envelope indicating a range of values
as a function of the specific valuation procedures. These pro-
cedures in turn can be correlated with specific water uses and
values, some of which will not necessarily be affected by a
spill. Therefore, one must select the valuation method which
reflects uses directly impaired by spills and employ that method
as the basis of assessing environmental harm.
Five basic valuation methods were employed in constructing
Figure IV—3.
1. Cost of Constructing and Operating Treatment Facilities
to Maintain or Improve Quality in the Receiving Water -
These values should be considered as minimum ones since
it is implied that the water quality is worth at least
that much to society or the’ facilities would not have
been built.
2. The Recreational Benefits Derived from the Water Body -
These values are typically derived on a user—day basis
with dollar values established for the average recreation
day. Most values include sport fishing, boating, and
swimming activities.
3. The Purchase Price — These values represent the sale of
the lake in question. These may be overvalued since land
is included in the purchase to varying degrees and cannot
be separated out on a fractional cost basis.
4. The Cost of Constructing and Maintaining an Artificial
Lake - These values relate the experience of state agencies
and private developers in creating new lakes.
5. The Value Foregone with Loss of the Lake - This methodology
includes values billed as the “total social” worth of a
lake and the use values attributed to lakes with exceptionally
high use rates, such as small water bodies in highly urban-
ized areas.
11—43
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1,000,000,000
10,000,000
1,000,000
100,000
10,000
10
0 100 200 300 400 500 600 700
UNIT VALUE IN $/ACRE—FEET
FIGURE IV-3.
UI’ IT VALUES FOR A GIVEN VOLUME OF LAKE WATER AS
A FUNCTION OF OVERALL LAKE SIZE (NUMBERS ARE
KEYED TO DESCRIPTIVE MATERIAL CONCERNING VALUA-
TION METHOD AND REFERENCES WHICH ARE GIVEN IN
APPENDIX B)
100,000,000
z
1-4
N
I - I
(I
a
1,000
100
11—44
-------
Specific derivations for each of the points in Figure IV-3 are
listed in the notes contained in Appendix B.
Of the evaluation methods employed, only the second deals with
uses directly affected by hazardous material spills (i.e., sports
fishing and water contact recreation). The first method merely
sets a minimum value level while the third method includes
additional land and other considerations which cannot be segre-
gated. The fourth and fifth methods also include other use
considerations such as property value considerations, aesthetics,
and flood control which will not be totally lost as a result of
a spill. The best fit relation illustrated is that for the
second valuation method, recreational benefits, which is defined
as the pertinent value system for this analysis. It is readily
apparent that the pertinent marginal values vary with the
size of the lake. The weighted average present wcrth was
found to be $63.47/acre-foot or $3.20/acre-foot/year.
(weighting was based on volume.)
This compares quite favorably with the $3-5/acre-foor/year by
the National Water Commission for recreational waters. It is
law, however, when compared with estimates by the Council on
Environmental Qualtiy as to the expenditures required to meet
present water quality goals for 1982 ($18.2 billion/year) 5 as
allocated to average annual runoff (2 x acre—feet/year) :6
$9/acre-foot/year. It is also low compared to values developed
by the U. S. Water Resources Council and the U. S. Fish and Wild-
life Service for recreational expenditures for sport fishing.
These and other values are compared and evaluated in Table IV-l.
Considering the comments in Table IV-l, it would appear that the
$9 figure of expenditures required is a maximum value. That is,
allocations and actual compliance with 1982 goals may fall short
of the required amounts. At the same time, the relative size of
this value and the admitted conservative nature of the Colorado
State University work suggests that the high end of the $3—S/acre-
feet/year range is most appropriate. With this in mind, $5/acre-
feet/year has been selected as the value of lake waters. This
corresponds with an annual value of $0.0042 per cubic meter and
a present worth of $0.067 per cubic meter ($83 per acre-foot).
Therefore, for the purposes of this methodology, the critical
volume for lakes has been selected as 74,277 cubic meters (60.24
acre-feet).
L+uWater Policies for the Future,” final report to Congress
of the National Water Commission, USGPO, June 1973.
5 ”Environmental Quality - 1974,” Fifth Annual Report of
the Council on Environmental Quality, Washington, DC,
USGPO, December 1974.
6 Todd, D. K. The Water Encyclopedia, the Maple Press
Company for the Water Information Center, 1970.
11—45
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TABLE IV-1
VALUATION OF FRESHWATERS IN U. S. BY VARIOUS SOURCES
Value
( S/Acre Feet/yr) Method Employed Comments
$3—S5 Colorado State University & Conservative Valuation Method
National Water Commission Employed
Estimates
$.38 Average of Recreational Values Limited Data on Lakes only -
Derived by Authors Some Admittedly Undervalued
$2—$4/acre-feet Cost of Rehabilitating Fish Duration of Effectiveness is
Lakes in Oregon Variable
51.50—529/acre— Cost of Rehabilitating Fish Duration of Effectiveness is
feet Lakes in New York Variable
$2—$l2 Cost of Constructing Recre- Highly Dependent on Local
ational Lakes in Colorado Variables
$9 Cost of Meeting 1982 Stand— Assumes most cleanup will
ards allocated to Anual Runoff Effect Rivers
$12 Expenditures for Sport Fishing Assumes three Spent Per
Recreation Day and only
Values Waters used for
Fishing
SELECTION OF A CRITICAL VOLUME FOR ESTUARIES
Estuarine values were collected on the basis of revenues for sport
and commercial catches. In this case, the values were found to be
more closely grouped. In turn, estuarine values were found to
have little scatter when total present worth was plotted against
total acreage, as in Figure IV—4. The typical evaluation method
involved determination of the dollar value of annual commercial
and sport fishing activities. The individual quantities employed
are given in the notes in Appendix B. Little change in marginal
values was found with increased size. This is reasonable since
the average productivity does not change directly with size.
The value for the nation, however, is larger, $1273/acre, than
the average for the ten estuaries studies, $712/acre. Both
values are much lower than the value of $4280/acre derived
by sport fishing interests. ’
This latter figure is high because only the productive estuarine
systems were considered. Given these considerations, the national
average, value No. 1 in Figure fll-4 was selected as the pertinent
value. If an average depth of 3.0 meters (10 feet) is assumed,
this corresponds to a present worth of $0.1016 per cubic meters
($127/acre—feet) and a critical volume of 49,212 cubic meters
(39 acre’feet).
7 Sullivan, C. R. “Economic and Social Significances of Sport
Fishing,” National Conference on Complete Water Reuse,
AICHE-EPA Technology Transfer Series, April 23-27, 1973.
11—46
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POINT NO. ACRES
1
30, 000, 000
VALUE($)
38, 200,000,000
/ACRE
(1273)
2
3
4
5
6
7
8
9
10
11
2,815
70,000
132,000
550, 000
3,000
4,600,000
51,900
1,648,000
476,000
70,000
46,400,000
232,000,000
260,000,000
404,000,000
5,990,000
2,850,000,000
174,000,000
383, 000, 000
369,000,000
695,000,000
(16,483)
(3, 314)
(1,969)
(735)
(1,997)
(620)
(3, 353)
(232)
(775)
(9,929)
H
10
e— 11
©
io,cxjo
‘
1 oQo,oOo
1o,ooO. o
PRESENT WORTH VAWE $)
Joo, xJ i,c J o
1o,oOO,oOO,O J 1OO, 3O,OOO,OOO
FIGURE IV-4. PRESENT WORTH OF ESTUARINE SYSTEMS AS A FUNCTION OF THEIR SIZE
-------
SELECTION OF A CRITICAL VOLUME FOR RIVERS
An attempt was made to value rivers in much the same manner that
lakes were valued. It quickly became evident, however, that
there were problems inherent in this approach which could not
be reconciled. A major stumbling block was the method of
valuation. The few attempts that have been made to value rivers
have focused on river frontage or run length as the basic unit
rather than volume of water. Without a volume specified, no
means exists to transform critical concentrations into harmful
quantities. Secondly, it was found that the few valuations
that have been made are insufficient to formulate any relations
which can be applied to rivers as a whole.
With these limitations in mind, it is apparent that, for the
present, river water must be valued on a volume basis through
correlation to the lake values obtained. This concession is
more soundly based than might appear in that many lakes are
indeed reservoirs on rivers, and the interchange between lakes
and rivers in terms of sources and outlets is often very impor-
tant.
There are two considerations with major impact on the value of
river waters versus the value of lake water. The first relates
to the fact that a single plug of contaminated river water may
move downstream and, consequently, may threaten an aquatic
community much larger than would normally reside in that volume
of water alone. For instance, a plug of toxicant will not only
kill fish in that volume of water but may also kill other fish
which it passes in the river until it is diluted below the
critical concentration. This consideration suggests then that
river water must be valued higher than lake water because a
given plug can produce more damage.
The second consideration concerns the dispersion aspects and
regenerative capacity of the river. The flowing river inherently
is associated w:.th far greater forces of mixing than impounded
water and thus can dilute a spill to nontoxic levels much more
rapidly than lake water which relies heavily on diffusion
dynamics. At the same time, the river is constantly replenishing
itself with water and life forms from upstream. These charac-
teristics would suggest that greater amounts of materials could
be assimilated without substantial harm and, hence, harmful
quantities should be larger and rates of penalties smaller than
those for discharges to lakes.
There is no rigorous manner in which these two forces can be
quantitatively evaluated. Consequently, the harmful quantities
derived for lakes were also applied to rivers. Implicit in
this interchange of values is the assumption that it is the
11—48
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volume of water potentially damaged which is being valued, and
that in this context a given volume of river has the same
recreational value as the same volume of lake water. This does
not imply that rates of penalty will be equivalent, however.
Modifying factors have been derived to adjust penalties with
respect to the actual dispersal characteristics of the receiving
water. These factors will be discussed in depth in a subsequent
section of this chapter.
SELECTION OF CRITICAL VOLUME FOR COASTAL WATERS
Coastal waters also pose a major problem in terms of valuation.
It is estimated that there are some 3.5 x 1013 cubic meters
(2.8 x 1010 acre-feet) of water included in the twelve mile
contiguous zone of the United States. These waters have
direct effects on commercial fishing, a limited amount of sport
fishing, boating, and recreational marine swimminq. 10 It is
estimated that the total landed value of fishes from these waters
is less than $500 million annually. (This figure is based on
the 1972 harvest of commercial species less $200 million worth
of estuarine dwelling shellfish). Annual receipts from swimming
have been estimated at $1.5 billion. 9 If one assumes an in-
finite series of annual income at this level and a rate of
interest of six percent, this is equivalent to a present worth
of $33 billion, or $973 per million cubic meters ($1.20 per
acre-foot) of coastal water. On the other hand, pollution of
these waters threatens the estuarine environment because of
the continual interchange between the two. Therefore, additional
value must be ascribed to coastal waters on the basis of their
influence on estuaries. It is estimated that the Nation’s
estuaries include some 3.7 x 1011 cubic meters (3 x 108 acre-
feet) of water [ derived assuming an average estuarine depth
of 3 meters (10 feet)]. 1 This is approximately one percent of
the volume of coastal waters. At any one time, the interchange
between coastal waters and an estuary is likely to approach a
state of one-to-one mixing; that is, half of the water in the
estuary is derived from coastal waters [ based on tidal intrusion
of 1.5 meters (5 feet), which is 50 percent of the 3 meters (10 feet)
depth assumed]. The tidal interchange for the estuary of Grays
Harbor, Washington, has actually been measured at 50 percent of
the volume. Moreover, the average salinity of the Harbor is
half that of typical coastal waters. Certainly, 50 percent is
the right order of magnitude since in the extremes one can note
8 National Oceanographic and Atmospheric Administration, National
Marine Fisheries Service, Washington, DC, (unpublished data),
May 1974.
9 U. S. Department of Commerce, Development Potential of U. S. Con-
tinental Shelves , p. 111—64, April 1966.
10 Battelle Memorial Institute, “The Economic and Social Importance
of Estuaries,” EPA, April 1971.
11—49
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salt marshes with no freshwater input and estuaries at the mouth
of major rivers where the salt is diluted to very low levels.
Salinity is bounded on the low side by the ability of shell-
fish to survive in dilute solutions. The combined effect of
these factors is such that 0.5 percent of contaminated coastal
waters could potentially contaminate the estuaries. Thus, the
value of coastal waters can be calculated by adding their
intrinsic value, $973 per million cubic meters ($1.20 per acre—
foot), and 0.5 percent of the value of estuarine waters, $508
per million cubic meters ($0.64 per acre—foot), to get $1511
per million cubic meters ($1.84 per acre—foot). This then
becomes the basis for calculating the harmful quantity and rates
of penalty to be employed for spills in coastal waters. The
specific values and associated critical volumes with a value of
$5,000 are summarized for all water body types in Table IV—2.
TABLE IV-2
SPECIFIC VALUES AND ASSOCIATED CRITICAL
VOLUME WITH A VALUE OF $5,000 FOR
THE FOUR BASIC WATER BODY TYPES
Critical Volume
Value ( $5,000 value level )
Lake $0.07/cubic meter 74,277 cubic meters
($83/acre—foot) (60 acre-feet)
River $0.07/cubic meter 74,277 cubic meters*
($83/acre—foot) (60 acre-feet)
Estuary $0.10/cubic meter 49,212 cubic meters
($127/acre—foot) (39 acre-feet)
Coastal Waters $1511/million cubic 3.31 million cubic
meters ($1.84/acre—foot) meters (2717 acre—feet)
*This is equivalent to one day’s flow in a stream flowing at
2.04 cubic meters per second (30.2 cfs) and is tantamount to
using a flow of 8.2 cubic meters per second (121 cfs) in the
DOHM plug flow model developed in Chapter VII.
Once these levels have been selected, calculations can be made
to derive the specific harmful quantity and rate of penalty for
each hazardous material. Example calculations for freshwater
lakes are illustrated in the following section.
11—50
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EXAMPLE HARMFUL QUANTITY CALCULATIONS
Inherent in the Resource Value Methodology approach to designation
of a harmful quantity is the assumption that some degree of
environmental damage will be tolerated. The threshold level of
damage to be employed has been selected as $5,000 and freshwater
lakes are valued at $0.07 per cubic meter ($83 per acre-foot).
This means that the harmful quantity is defined as the amount
of a material required to contaminate 74,277 cubic meters
(60 acre-feet) of water (19,551,000 gallons). The amount of a
hazardous material required to critically pollute this volume
is the product of this volume of water and the critical concen-
tration at which potential harm occurs. Similarly, the harmful
quantities for the remaining three water body types can be cal-
culated using the appropriate values from Table IV-2. These
threshold levels have been calculated for the hazardous materials
being evaluated:
Freshwater
Acetaldehyde = 53 ppm (96 hr TLm for bluegill)
Cadmium Sulfate = 5.6 ppm as Cd (96 hr LC5 0 for
fathead minnow)
Saltwater
Phenol = 24 ppm (48 hr LC 50 f or shrimp)
Hence, the respective harmful quantities (HQ) can be calculated
for the various water body types as follows:
Acetaldehyde - Lake
HQ = 19,551,000 (qal) x 53 (mg/i) x 8.3 x l0 (lbs—i/mg—gal)
= 8700 lbs or 3906 kg
Cadmium Sulfate - River
HQ = 19,511,000 (gal) x 5.6 (mg/i)
x 8.3 x io— (lbs—i/mg—gal)
= 920 lbs or 420 kg
Phenol - Estuary
HQ 12,708,150 (gal) x 24 (mg/i) x 8.3 x l0
(lbs-i/mg-gal)
= 2541 lbs or 1154 kg
Phenol - Coastal Zone
HQ = 3.87 x 10 (gal) x 24 (mg/i) x 8.3 x 10—6
(lbs-i/mg-gal)
= 172,446 lbs or 79,140 kg
11—51
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INITIAL RATE OF PENALTY
The rate of penalty is defined as the value of potential damage
to the environment. Since the harmful quantity is defined as
the amount of a material required to damage $5,000 worth of
aquatic environment, the rate of penalty is simply
R of P 0 = $5,000/HQ.
This is considered only a starting point, however, since there
are many receiving water influences and chemical characteristics
which cause the probable damage to differ from the maximum
‘potential damage. To account for the differences and subsequently
adjust the rate of penalty, a modifying factor must be applied.
ADJUSTMENT FACTOR
It is recognized that the physical characteristics of many
materials and receiving waters can prevent rapid dilution to
threshold concentrations and indeed may allow for removal or
destruction of a portion of the material. The formulation
employed thus far, however, assumes instant mixing to an
isoconcentration state at the critical concentration level
which generates the maximum possible volume effected. There-
fore, it is important to modify any rate of penalty determination
by a factor which reflects the difference between maximum
possible volume effected and the most probable volume affected.
This adjustment factor has been designated rk.
By definition, rk must be comprised of both intrinsic and
extrinsic components. Hence, the final rate of penalty (R of
is derived by operating on the original rate (R of P 0 ) with the
various rk components:
R of = (R of P 0 ) (rk) (R of P 0 ) (rk int) (rk ext)
With reference to the law, the intrinsic components reflect the
concern for considering the degradability and dispersibility of
the spilled material as mandated in Section 311(b) (2) (B) (iv),
while the extrinsic components relate to the “...times, locations,
circumstances, and conditions...” referred to in Section 311(b) (4).
Both the intrinsic and extrinsic components can be further
divided into individual factors as discussed below.
Intrinsic Factors
There are two factors of importance in the intrinsic component:
one related to the persistence of the material and hence the
duration of harmful effects, and one related to the ability of
the material to spread in the environment at toxic levels.
11—52
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The first factor, designated Anf, addresses the duration of the
impact of a spill. In the derivation of the basic rate of
penalty, volumes of water are associated with a value estimated
as the total present worth to society of the water in a natural
system. In many cases, setting rates of penalty at that high a
level would be unfair since spills of most substances will
devalue the water for a finite time period but not destroy it
forever. To reflect this, the Anf, or annuity factor, has been
devised to convert the base rate of penalty to one commensurate
with the present worth of an annuity lasting for the number of
years over which the impact of the spill is likely to persist.
The yearly amount of the annuity is set at the level which
taken over an infinite life at six percent interest would yield
the present worth estimated for the water or, put more simply,
six percent of the present worth value now associated with the
water. For example, freshwater is valued at a present worth of
$0.07 per cubic meter ($83 per acre—foot) so the amount of the
annuity would be $0.07 (.06) = $0.0042 per cubic meter per year
[ $83 (.06) = $5 per acre-foot per year]. The annuity factor
would then be the present worth of $0.0042 per cubic meter per
year ($5 per acre—foot per year) for x years where x is the
period over which the impact persists. This can be reduced to
the form:
Anf — PWa (6%, x yrs )
— PWa (6%, yrs)
where
Anf = annuity factor
P 1a = present worth factor
x = impact period for material spilled
PvJa (6%, yrs) = 16.7
Each material is then classified according to the potential
duration of effects from an acute spill. The material’s classi-
fication is associated with & time span which then defines x for
a spill of that material. The values of x selected for each
classification of hazardous materials are presented in Table IV-3.
No material is credited with an impact duration of less than one
year. While the acute lethality may be exhibited in a few short
hours, one year is considered a reasonable requirement for
repopulation. For example, when fly ash was discharged into
the Clinch River, it was estimated that it would take a full
summer for benthic life to return to normal population levels. 11
11 ”Clinch River Fish Kill, June 1967,” U. S. Department of the
Interior, Federal Water Pollution Control Administration,
Middle Atlantic Region, Charlottesville, VA, June 1967.
11—53
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TADLE IV-3
IMPACT PERIODS ASSIGNED TO MATEPIAL CLASSIFICATIONS FOR
USE IN DERIVING THE Anf FACTOR (PERIODS GIVEN IN YEARS)
Water Body Type
Material Classification Lake River Estuary Coastal Zone
Organic — Degradable 2 1 3 1
Persistent 3 1 4 2
BioconcentratiVe 5 5 2
Inorganic — Bioconcentrative 5 2 5 2
Nonbioconcentrative 2 1 3 1
When additional time is added to account for higher trophic
levels, one full season of recreational activities is essentially
lost.
Longer impact periods have been assigned to lakes where aeration
and repopulatjon processes may be slower. A minimum impact
period of three years has been attributed to estuaries where
non—mobile shellfish species require the extra time to reach
maturity.
Bioconcentrative materials have been assigned a five year
impact period for the more static water bodies where environ-
mental cycling and accumulation in the food chain can extend
the potential effects of a spill over a long period. While
workers in Sweden have estimated that mercury contaminated
lakes in that country may require 100 years to cleanse them-
selves, 12 natural sedimentation and chemical processes are
likely to inactivate spilled materials in a much shorter time.
Work with toxaphene 13 - 15 has revealed that impact times are
2 Jernelov, A. “Conversion of Mercury Compounds,” Chemical
Fallout , Chapter 4, Thomas Springfield Co., 1969.
13 Johnson , W. D., G. F. Lee, D. Spyridakis. “Persistence
of Toxaphene in Treated Lakes,” Air & Water Pollution mt.
Journal , Pergamon Press, Volume 10, 1966.
11—54
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highly varied, but usually do not exceed five years. Similar
work in estuaries gave comparable results.’ 6 Persistent materials
are credited with impact periods between the two extremes. The
shorter effect times accredited to coastal water spills reflect
a result of ocean dumping studies in the Gulf-Coast area. 17
The present worth factors (PWa) for the associated annuities
and the consequent Anf Factors are given in Table IV—4.
From the table it can be seen that the spill of a persistent
organic into a lake will result in a base rate of penalty
(R of approximately one sixth the estimated present worth
of the water potentially affected:
R of (R of P 0 ) (.16)
Similarly, if the material had been bioconcentrative, the rate
of penatly would be one quarter the base rate of penalty since
the Anf would be 0.25.
The second factor in the intrinsic component is one related to
the inherent ability of the material to spread through the
environment at toxic levels. It has been designated Disp and
must consider both the physical/chemical properties of the
material (such as specific gravity, solubility, and volatility)
as well as the critical resources which would potentially be
damaged in a given type of water body. In order to assign
factors, the materials were categorized into groupings
based on their predicted response to spillage in water. A
multidisciplinary panel of scientists from the Pacific Northwest
Laboratories of Battelle Memorial Institute was then asked to
assign Disp factors for spillage of a classification of material
into a specific water body type. Miscible substances were
identified with a Disp of 1.0 to act as the base comparator for
‘ Cushing, C. E. Jr. and J. R. Olive. “Effects of Toxaphene
and Rotenone Upon the Macroscopic Bottom Fauna of Two
Northern Colorado Reservoirs,” transactions of the American
Fisheries Society.
‘ 5 Gebhards, S. V. “A Review of Toxaphene for Use in Fish
Eradication,” prepared for State of Idaho, Department of
Fish and Game, March 3, 1960.
16 Reimald, R. J., P. C. Adams and C. J. Curant. Effects of
Toxaphene Contamination on Estuarine Ecology , Georgia Marine
Science Center, Technical Report Series No. 73—8, September
1973.
17 Battelle Memorial Institute. Program for the Management of
Hazardous Wastes , EPA, Contract No. 68-01-0762, July 1973.
11—55
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TABLE IV-4
PRESENT WORTH OF ANNUITY AND Anf FACTORS ASSOCIATED
WITH THE SELECTED IMPACT DURATION PERIODS
Water Body
*pWa refers to present worth factor at 6% for X years where X is the impact period
assigned to each classification in Table IV-2.
H
0 1
Material Classification
Lake
River
Estuary
Coastal
Zone
PWa*
1.83
Anf
0.11
PWa
0.94
Anf
0.06
PWa
2.67
Anf
0.16
PWa
0.94
Anf
0.06
Organic — Degradable
Persistent
2.67
0.16
0.94
0.06
3.47
0.21
1.83
0.11
Bioconcentrative
4.21
0.25
2.67
0.16
4.21
0.25
1.83
0.11
Inorganic — Bioconcentrative
4.21
0.25
1.83
0.11
4.21
0.25
1.83
0.11
Nonbioconcentratjve
1.83
0.1].
0.94
0.06
2.67
0.16
0.94
0.06
-------
the four water types. The subsequent factors were then selected
to rate other categories on the basis of their propensity to
spread more or less than a miscible substance and to affect the
most critical sector of the host environment. The results of
the panel’s independent scoring are presented in Table IV-5.
For the purpose of the classification process, the following
definitions were employed:
miscible - liquid substances which can freely mix wjth
water to any proportions or have a solubility
>1,000,000 ppm
mixes — solid substances which freely mix with water or
have a solubility >1,000,000 ppm
precipitates - salts which disassociate in water with
the subsequent precipitation of the toxic ion
insoluble, volatile, floats - materials lighter than
water with a vapor pressure >10 mm Hg and a solubility
<1,000 ppm or materials with solubility <10,000 and
vapor pressure >100 mm Hg
insoluble, nonvolatile, floats - materials lighter than
water with a vapor pressure <10 mm Hg and solubility
<1,000 ppm
soluble, floats — materiai . lighter than water and solubility
>1,000 ppm
insoluble, sinks - materials heavier than water and
solubility <1,000 ppm
soluble, sinks — materials heavier than water and
solubility >1,000 ppm
Several specific interpretations can be seen from Table IV—4.
In general, miscible substances were felt to have the maximum
potential for spreading in the critical sector of the environ-
ment. The three exceptions were sinking and precipitating
materials in estuaries where shellfish are a major factor in
the value of the resource. Floating substances received some-
what higher ratings than those which sink in coastal waters
because of the surface transport processes which would bring
spills into the beach and estuarine zones.
The individual factors that make up the intrinsic component
are multiplicative and, consequently, the total intrinsic
component is defined as
rk mt (Anf) (Disp)
11—57
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TABLE IV-5
RELATIVE Disp FACTORS FOR VARIOUS WATER BODY TYPES
Water Body Type
Material Classification Lake River Estuary Coastal Zone
Miscible 1.0 1.0 1.0 1.0
Mixes 0.84 0.80 0.84 0.78
Precipitates 0.73 0.71 1.3 0.55
Insoluble, Volatile, Floats 0.31 0.31 0.27 0.35
Insoluble, Nonvolatile, Floats 0.74 0.62 0.60 0.94
Soluble, Floats 0.86 0.86 0.82 0.86
Insoluble, Sinks 0.59 0.58 1.35 0.43
Soluble, Sinks 0.83 0.85 1.05 0.59
-------
Individual intrinsic component values for each of the designated
hazardous substances are detailed in Appendix C.
Extrinsic Factors
The extrinsic component is similar to the intrinsic component
in that it too is derived as the produce of two individual
factors: ResU, the resource use modifier and Loc, the locational
dispersion factor. Thus,
rk ext = (ResU) (Loc)
The extrinsic factors are designed for selection after the fact.
They serve to adjust the penalty to align it more closely with
actual damages.
The resource use modifier is designed to reflect the extent to
which the spill site environment deviates from the average
employed to derive the original rate of penalty; that is, it
recognizes that a broad range of values can be attributed to a
single water body depending upon the type and extent of use it
sustains. Hence, if a water body does not presently sustain
a healthy aquatic community, penalties for spills will be
adjusted downward, while penalties for spills in high use
recreational water bodies will be elevated. Ideally then, the
ResU factor is derived by dividing the estimated present worth
of the receiving water by the value used for the base rate of
penalty. Therefore, if the estimated present worth is X per
cubic meters, one uses
Lake — ResU = .07
x
River — ResU =
x
Estuary - ResU =
x
Coastal Water — ResU = 0015
If annual values for the damaged resource are known, the present
worth at six percent used previously can be converted to annual
values by dividing the denominator by 16.7. Consequently, for
an annual value of $Y per cubic meter, the corresponding ResU
factors are:
Y
Lake — ResU = .0042
River - ResU = .0042
11—59
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Y
Estuary - ResU = .006
y
Coastal Water — ResU = .00009
It is recognized that for many water bodies, the annual values
or present worth values will not have been estimated. In the
event of a spill into these waters, ResU factors can be obtained
directly from Figure IV-5.
The values employed here were derived largely from the charts
presented in Figures IV—3 and IV-5.
The location dispersion factor, Loc, is formulated to adjust
the rate of penalty to take into account the natural dispersive
forces in the receiving water. The basic model assumes instan-
taneous mixing to an isoconcentrative state at the critical
concentration. This clearly leads to the use of the maximum
potential volume affected as the volume damaged by a spill.
In actuality, material dispersion patterns will lead to smaller
volumes of affected water. To account for this, Loc has been
defined as:
L — predicted actual volume
oc — instantaneous mix maximum volume
For each application, then, it is desirable to construct a set
of matrices yielding Loc, the ratio of the two volumes. This
would then allow quick selection of the appropriate Loc factor
for any given spill. In order to derive the numerator, the
predicted volume, one must employ a quantitative formulation.
A computerized hydrodynamic model was selected for this purpose.
Parameters were then selected for use as independent variables
in the model.
Two criteria were applied in selecting input parameters for the
various water body types:
1. The parameters should be significant with respect to effects
on the dispersion of a spill into the water body type of
interest, and
2. The parameters should . either well catalogued values
available on many potential receiving waters or should be
subject to close estimation by on-scene personnel.
Utilizing these criteria, the following selections were made:
Lake - average depth and angle of descent fr6m the shoreline
to the point of average depth. Advective currents were
assumed to be 0.11 kilometers per hour (0.1 fps) parallel
to the shoreline and nil in the other directions.
11—60
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FRESIMATER - LAKES AND RIVERS
, 4.’
ResY .01 .025
FACTOR
4,
USE
LEVEL
C,
I I I I
0.1 0.2 0.5 1.0
I I I 111111 I I I IIIII I I I 111111 I I 111111 S I 111111
V
-J
24.0
SALTWATER - ESTUARIES AND COASTAL WATERS
4 ,
USE
LEVEL
ResV 0.1
FACTOR
is
47
#1
I
0.2 0.5 1.0
I I I I , i I I
4.0 8.0
I I I
H
C’
I - ’
J.
7.0
8
C,
.
I
I
FIGURE IV-5.
VALUATION CHARTS FOR ASSIGNING ResU FACTORS TO WATERS OF UNKNOWN VALUE
-------
River — flow rate and flow velocity. These two parameters are
subsequently used in Ward Type Equations to derive physical
dimensions to be employed as boundaries in the model.
Dispersion coefficients are also varied as a function of
flow rate and velocity.
Estuary — models for estuarine systems could not be simplified to
two variables without designating where in the estuary the
spill occurs. Consequently, it is recommended that the model
be used for all spills except those outside the major current
pattern where the coastal water model should be employed.
Coastal Waters - average current velocity and average depth.
The depth, however, is generally too great to act as a
barrier to dispersion. Consequently, it is held constant
and only the current velocity is varied.
The model employed focused on developing a semi—analytical
solution to the governing equation considering variable diffusion
coefficients, transforms, Green’s function, and the method of
image sources to avoid the finite differences approach. The
model is described in detail in Appendix D.
Output from the model is the volume of water (V) contained by
the isoconcentration lines at a given critical concentration
level (CC) for a fixed quantity of spilled material (M). The
maximum volume attainable with instant mixing is simply
Vmax = M/CC
Therefore, the location factor becomes
Loc = V/Vmax
= v/M/CC = V(CC)/M
These dimensionless fractions are tabulated in Appendix D for
the various parameter combinations employed. It should be noted
that the ratio of volumes changes when different concentration
levels are employed as the critical concentration. Consequently,
adjustment relations have been approximated from the output of
discrete model runs. These relations are also explained in
Appendix D. It is also important to note that no model is
applicable to all water bodies. Therefore, individual LOC
factors are not important so much as the order of magnitude
they occur at. For instance, the data tabulated suggests
that spills in lakes and coastal waters will threaten only
about 18 percent of the maximum possible volume of water while
for spills in rivers and estuaries the rates is closer to
3.6 percent. These numbers were obtained as the average of
those presented in Appendix D after extreme conditions, e.g.,
900 angle of descent were discarded.
11—62
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Summary
In summary, rates of penalty should be a function of both
intrinsic factors related to the substance spilled and extrinsic
factors related to the site of the spill. While the intrinsic
factors can be assessed extant and thus are included in the
base rate of penalty for each hazardous substance, the extrinsic
factors require varying degrees of on—scene evaluation. These
post spill determinations, however, have been simplified through
the development of nomographs and matrices from which the appro-
priate adjustment factors can be quickly selected.
It must be recognized that no attempt has been made to define
rk as a natural phenomenon. Rather, the rk factor is designed
merely as a transform to produce the appropriate effects on the
rate of penalty under varying conditionS. Thus, rather than
describing underlying universal interrelations, the rk relations
merely provide a desired transform for modification of rates of
penalty from values representing maximum potential damage to
those representing probable or actual damage.
DETERMINATION OF THE FINAL RATE OF PENALTY
The final rate of penalty will be set such that the incremental
penalty per unit of measurement approximates the value of the
environment potentially damaged by the spill. This is done by
taking the product of the value of the environment, $0.07 per
cubic meter ($83 per acre-foot) for lakes and rivers; the
volume of environment contaminated by the harmful quantity,
74,277 cubic meters (60 acre—feet) per HQ tor lakes and rivers;
and the adjustment factor rk, or more si r.ply, $S,O00/l Q.
flence, the final rate of penalty, R of is
R of = (value/unit environment) (critical volume/HQ) (rk)
R of 1 ’F ($5,000/HQ) (rk)
The extrinsic components cannot be added until after the fact.
The intrinsic ones can, however, be employed at this time to
establish the base rate of penalty (R of PB). Example calcula-
tions are made below:
Acetaldehyde - Lakes
R of B = 83 ($/acre—foot) x 60/4.3(acre—feet/ton) x
(.11) x (1.0)
R of $128/ton = $141/metric ton
11—63
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Cadmium Sulfate - Rivers
R of = 83($/acre-foot) x 60/908(acre-feet/lb) x
(.11) x (.71)
R of = $0.43/lb $0.94/kg
Phenol - Estuaries
R f B = 127($/acre-foot) x 39/2541(acre-feet/lb) x
(.16) x (1.05)
R of = $33/100 wt — $0.73
To illustrate how the extrinsic factors are brought into the
formulation, consider the case where the acetaldehyde spill
occurred in a residential lake with low water contact usage,
an average depth of 7.6 meters (25 feet), and an angle of
descent of 450 From Figure IV-8, the ResU factor is determined
to be 0.5. From Appendix D, the Loc factor for a critical
concentration of 50 can be taken as that for a concentration of
5 times the ratio of that for 10 to that for 1, or
/Loc \ 078
Loc 50 Loc 1 ) (Loc 5 ) = (:074) (.061) = .064.
Therefore, the final rate of penalty, R of F’ can be determined
asRofPFRofPBx (rkext).
R of = $202/ton x 0.5 x .064
R of = $6.46/ton = $7.12/metric ton.
Base rates of penalty without consideration for extrinsic factors
and harmful quantities as derived by the Resource Value Methodology
are compared to those resulting from the other methodologies in
Appendix N. It is apparent that if the economic rational is to
be maintained, penalty rates must be reviewed periodically and
adjusted to reflect changes in resource values and/or monetary
fluctuations.
11—64
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REFERENCES
1. Personal comunication, Thomas Maloney, EPA/NERC, Corvallis,
OR, February 13, 1974
2. Grad, F. A Treatise on Environmental Law , §2.03, 2—166, 1973.
3. Personal communication, Dr. A. L. Jennings, EPA/Division of
Oil and Hazardous Materials, Washington, DC, July 24, 1974.
4. “Water Policies for the Future,” final report to Congress
of the National Water Commission, USGPO, June 1973.
5. “Environmental Quality - 1974,” Fifth Annual Report of
the Council on Environmental Quality, Washington, DC,
USGPO, December 1974.
6. Todd, D. K. The Water Encyclopedia, the Maple Press
Company for the Water Information Center, 1970.
7. Sullivan, C. R. “Economic and Social Significances of
Sport Fishing,” National Conference on Complete Water
Reuse, AICHE—EPA Technology Transfer Series, April 23—27,
1973.
8. National Oceanographic and Atmospheric Administration,
National Marine Fisheries Service, Washington, DC, (unpublished
data), May 1974.
9. U. S. Department of Commerce, Developnent Potential of U. S.
Continental Shelves , P. 111-64, April 1966.
10. Battelle Memorial Institute, “The Economic and Social
Importance of Estuaries,” EPA, April 1971.
11. “Clinch River Fish Kill, June 1967,” U. S. Department of
the Interior, Federal Water Pollution Control Administration,
Middle Atlantic Region, Charlottesville, VA, June 1967.
12. Jernelov, A. “Conversion of Mercury Compounds,” Chemical
Fallout , Chapter 4, Thomas Springfield Co., 1969.
13. Johnson, W. D., G. F. Lee, D. Spyridakis. “Persistence
of Toxaphene in Treated Lakes,” Air & Water Pollution mt.
Journal , Pergamon Press, Volume 10, 1966.
14. Cushing, C. E. Jr. and J. R. Olive. “Effects of Toxaphene
and Rotenone Upon the Macroscopic Bottom Fauna of Two
Northern Colorado Reservoirs,” transactions of the American
Fisheries Society .
11—65
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15. Gebhards, S. V. “A Review of Toxaphene for Use in Fish
Eradication,” prepared for State of Idaho, Department of
Fish and Game, March 3, 1960.
16. Reimald, R. J., P. C. Adams and C. J. Curant. Effects of
Toxaphene Contamination on Estuarine Ecology , Georgia Marine
Science Center, Technical Report Series No. 73—8, September
1973.
17. Battelle Memorial Institute. Program for the Management of
Hazardous Wastes , EPA, Contract No. 68—01—0762, July 1973.
11—66
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V. THE MODIFIED IMCO/GESAMP METHODOLOGY
BRIEF
In this approach, hereafter referred to as the IMCO Methodology,
a procedure is developed for designating harmful quantities and
rates of penalty based on a proposed international hazardous
material rating/classification system which has been submitted
under the auspices of the United Nations to its member nations
for adoption. When adopted, it is anticipated that this system
will be used to regulate the operational discharges of ships
transporting liquid noxious substances in bulk. The hazardous
material rating/classification system upon which the IMCO Method-
ology is based was originally developed by an ad hoc coiuxnitI ee
of IMCO and GESAMP experts as part of an international effort to
bring about regulations that would reduce pollution of the sea
resulting from the discharges (both intentional and accidental)
of ocean-going vessels.
These regulations, like Section 311, are intended to bring about
a reduction in the release of hazardous materials to the environ-
ment; however, the concepts of harmful quantity and rate of
penalty are not present in these regulations and hence, modification
of the basic IMCO system is necessary in order to construct a
methodology which complies with the requirements of Section 311.
More specifically, the IMCO rating/classification system provides
a mechanism for differentiating between materials on the basis of
their various hazard potentials. The methodology developed below
uses this differentiation as a basis for deriving harmful quan-
tities and rates of penalty.
As an overview, the IMCO Methodology first utilizes the rating/
classification system developed by the committee of experts to
profile noxious substances (which may be considered hazardous
materials) on the basis of their relative hazard potentials.
These profiles are then used to relegate the hazardous materials
to hazard categories depending upon the degree to which they are
expected to exert their various hazard potentials. Once materials
have been relegated to one of the four categories, a critical
concentration is derived for each category. These critical con-
centrations are taken to be representative of the levels at which
the hazardous materials in a given category are expected to
present a substantial threat to the aquatic environment in a
spill situation. The resource value approach derived in Chapter IV
is then used to derive a critical volume of water (a volume
which, when contaminated to the critical concentration, results
in substantial harm) for each of the four general water body
types being considered by this study. These critical volumes
when multiplied by the critical concentrations yield harmful
quantities for each category in each water body type. Base rates
11—67
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of penalty are then computed by utilizing the ratio of the value
of the water to the mass of hazardous material required to contami-
nate the water to its critical concentration. For each designated
material, the base rate of penalty is then modified by an adjust—
ment factor which considers the ability of the material to exert
its full hazard potential(s) in a given water body type when
consideration is given to the physical/chemical properties of the
material. Adjustment factors are derived through the use of a
DELPHI technique. The designated materials are also profiled
with respect to their physical/chemical properties so that
appropriate adjustment factors can be assigned to each material.
For reader convenience, the steps in developing the IMCO Method-
ology are shown schematically in Figure V-i.
IMCO/GESAMP REPORT ON THE IDENTIFICATION
OF NOXIOUS AND HAZARDOUS SUBSTANCES
General
The Inter-Governmental Maritime Consultative Organization (IMCO)
is the depository of the International Convention for the Pre-
vention of Pollution of the Sea by Oil, 1954, which is committed
to examine the possibilities of formulating, in cooperation with
other United Nations agencies, suitable international agreements
aimed at preventing and controlling all pollution resulting from
activities of ships, craft, and equipment operating in the marine
environment. The Joint Group of Experts on the Scientific Aspects
of Marine Pollution (GESAMP) is an advisory body composed of
experts from a number of international organizations including
the Food and Agricultural Organization (FAO); the United Nations
Educational, Scientific and Cultural Organization (UNESCO); the
World Meteoroldgical Organization (WMO); the International Atomic
Energy Agency (IAEA); the World Health Organization (WHO); the
United Nations (UN); and IMCO.
In preparing for an International Conference on Marine Pollution
to be held in 1973, the IMCO Subcommittee on Marine Pollution
noted certain difficulties in utilizing the categories of pollu-
tants previously identified by GESAMP for developing control
measures for operational discharges and for the construction and
equipment. of ships carrying dangerous chemicals in bulk. To
resolve these difficulties, an ad hoc panel of IMCO and GESAMP
experts was convened to prepare a rated list of noxious and
hazardous substances for subsequent approval by GESAMP at its
fourth session. The work of the ad hoc panel resulted in the
submission of a report 1 to the fourth session of GESAMP held at
1 ”Report of an Ad Hoc Panel of IMCO and GESAMP Experts to Review
the Environmental Hazards of Noxious Substances Other Than Oil
Transported by Ships,” Joint Group of Experts on the Scientific
Aspects of Marine Pollution, London, England, 1972/73.*
*Algo contained in the congressional hearing report, “Hearing
Before the Committee on Commerce on 1973 IMCO Conference on
Marine Pollution from Ships, November 1973,” U. S. Senate,
93rd Congress, First Session, Series 93—52.
11—68
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FIGURE V-i. FLOW DIAGRAM FOR IMCO METHODOLOGY
PROFILED ON BASIS
OF PHYSICAUCHEMICAL
PROPERTIES
CATEGORIZED ON BASIS
OF HAZAR D P ROFI I.E
CRITICAL VOWME
DETERM I NED FOR
FOUR WATER BODY
TYPES
11—69
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WMO Headquarters, Geneva, Switzerland, September, 18-23, 1972.
In this report, a system for profiling hazardous materials on the
basis of their various hazard potentials was put forth along with
individual profiles on almost 400 hazardous materials evaluated
by the ad hoc committee. This report was adopted by the fourth
session of GESAMP.
At the 1973 International Conference on Marine Pollution, the
system developed by the ad hoc committee was used to draft regula-
tions for the control of pollution by noxious lic uid substances
transported in bulk. These proposed regulations provide the
foundation upon which the methodology described in this section
is based.
The IMCO System
The system developed by the ad hoc committee and later endorsed
by GESAMP is one which characterizes or profiles hazardous
materials shipped by water in bulk quantities. Specifically,
the chemicals considered were “all noxious and hazardous sub-
stances other than oil” 1 as defined by the 1954 Oil Pollution
Convention. The report characterizes these noxious materials
with respect to five hazard potentials:
• Bioaccumulatiori
• Damage to living resources
• Hazards to human health (oral intake)
• Hazards to human health (external exposure)
• Reduction of amenities
Appendix E contains a listing of these hazard potentials along
with the rating system used to differentiate degrees of hazard
Within each hazard potential. Also included in this appendix
is a sample page from the report which shows how this system
was used to profile individual chemicals.
At the time of this report, no attempt was made by the ad hoc
committee to select extremely hazardous materials out of those
being currently shipped. Rather, their task was to develop a
rationale for evaluation any substance which was carried as a
bulk liquid, dry, or package cargo. Details of the procedures
adopted by the committee for evaluating the substances are docu-
mented in their report 1 along with discussions of problem areas
2 ”Regu].ations for the Control of Pollution by Noxious Liquid Sub-
stances in Bulk, Annex II,” International Conference on Marine
Pollution, October 31, 1973.*
*Also contained in the congressional hearing report, “Hearing
Before the Committee on Commerce on 1973 IMCO Conference on
Marine Pollution from Ships, November 1973,” U. S. Senate,
93rd Congress, First Session, Series 93—52.
11—70
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such as quantifying bioaccuntulation potential and compromise
areas such as substituting animal LDSO values to determine the
hazard to human health. The reader is referred to the primary
document for these details.
The report of the ad hoc committee of experts was accepted by
the fourth session of GESAMP (1972/73), subject to the following
important technical considerations.
1. The Group recognized and approved that, in the absence of
sufficient data on lethal threshold concentrations, it had
been necessary to use LC 50 values. It was stressed that
there is limited biological significance in such values and
that evaluation of the threshold concentrations is preferable
and should be encouraged.
2. The Group cautioned that there was a real possibility that
the hazard ratings would be used for purposes other than
those specified in the IMCO inquiry. To elaborate, it was
felt that before the rationale and its table of ratings
could be used for other purposes, it would be necessary
to include additional or more detailed information partic-
ularly with respect to physical properties, bioaccumulatiofl
characteristics, persistency in the marine environment, long
term effects on the balance of the ecosystem, and the trans-
formation reactions of certain substances.
3. Some views were expressed concerning the interpretation of
hazard ratings of substances which bioaccumulate and which
might be repeatedly discharged in a given area.
4. The need for establishing a mechanism for continually up-
dating the list of substances was emphasized.
Since the ultimate goal of this undertaking was the development
of a set of regulations for the control of pollution by noxious
substances, it was necessary to extend the original work of the
ad hoc committee. This task was performed by government repre-
sentatives operating as a working group under the IMCO Marine
pollution subcommittee. Their work was eventually incorporated
into “Regulations for the Control of Pollution by Noxious Liquid
Substances in Bulk”, 2 a document adopted by the 1973 international
Conference Ofl Marine Pollution. The work of the subcommittee
centered around categorizing the subject noxious materials based
on the hazard profiles developed by the ad hoc committee as shown
in Appendix E. Four categories of hazardous materials were
developed by the subcommittee. 2
• Category A - Noxious liquid substances which, if dis-
charged into the sea from tank cleaning or deballasting
operations, would present a major hazard to either
11—71
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marine resources or human health or cause serious harm
to amenities or other legitimate uses of the sea and,
therefore, justify the application of stringent anti-
pollution measures .
• Category B - Noxious liquid substances which, if dis-
charged into the sea from tank cleaning or deballasting
operations, would present a hazard to either marine
resources or human health or cause harm to amenities or
other legitimate uses of tI.e sea and, therefore, justify
the application of special anti—pollution measures .
• Category C - Noxious liquid which, if discharged into
the sea from tank cleaning or deballasting operations,
would present a minor hazard to either marine resources
or human health or cause minor harm to amenities or
other legitimate uses of the sea and, therefore, require
special operational conditions .
• Category D - Noxious liquid substances which, if dis-
charged into the sea from tank cleaning or deballasting
operations, would present a reco izable hazard to
either marine resources or human health or cause minimal
harm to amenities or other legitimate uses of the sea
and, therefore, require some attention in operational
conditions .
NOTE: Authors’ underlines for emphasis.
Technical guidelines for these categories are contained in
Appendix F. These guidelines are based on the previous work of
the IMCO ad hoc committee and reflect the deliberations of the
1973 International Convention on Marine Pollution. 2
Under the regulations adopted by IMCO, various operational and
record keeping constraints are placed on ships employed in the
transport of the subject noxious substances. These constraints
vary qith the category of the material, the most severe con-
straints being associated with Category A materials and the least
severe constraints with Category D materials.
Applicability of the IMCO System to Determining Harmful
Quantities and Rates of Penalty for Hazardous Material Spills
Utilization of the IMCO system has the apparent advantage of
providing a ready—made system in which the characterization and
categorization of hazardous materials has already been accom-
plished by a body of experts representing an international
awareness of technical information. Hence, a methodology based
on this system carries in part the support of the credentials
of the international body of experts who formulated and approved
the system as well as the concerns of their governments which are
11—72
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in the process of approving the convention. The acceptance of
such a methodology based on an internationally recognized class-
ification system is perhaps more likely than one which has not
been subjected to prior scrutiny. In addition, the advantage
of domestic regulations which are compatible with an international
convention should not be overlooked. -
From a conceptual and operational viewpoint, an IMCO based method-
ology which considers hazard groups rather than individual
chemicals offers the advantage of simplicity relative to other
methodologies especially in terms of reporting and fine deter-
mination. Despite these advantages, the fact remains that the
IMCO system was not developed or intended to be used as a basis
for determining harmful quantities and rates of penalty for hazard-
ous material spills. Specific drawbacks include those listed below.
• The IMCO system is specific to a marine environment
whereas the rates of penalty and harmful quantity
regulations must apply to freshwater as well as salt-
water bodies.
• Although the IMCO system is capable of profiling and
categorizing any material, only liquid substances
shipped in bulk were categorized in Annex II of the
proposed international regulations. 2 As a result,
about 75 percent of the substances considered in this
study have not been categorized under the IMCO system.
Although the guidelines ( (see Appendix F) for catego-
rizing the hazardous substances are fairly clear, it is
also known that some degree of subjectivity entered into
the discussions of the IMCO subcommittee, Consequently,
the profiling and categorization of 75 percent of the
designated materials cannot fully duplicate the work of
the international body of experts.
• Rigorous or formal consideration of the physical/chemical
(as opposed to the toxicological) properties of the
hazardous materials is not evident in the IMCO system.
Section 311 requires that “degradability and dispersal” 3
characteristics be considered in determining rates of
penalty. Hence, modification of the existing IMCO
system to include formal consideration of physical!
chemical properties is necessary.
• Although the IMCO system does offer a basic framework
for categorizing hazardous materials, it does not
provide a ready mechanism for quantitating differences
3 public Law 92-590 and 92nd Congress of the United States,
October 18, 1972.
11—73
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between categories. Since Section 311 requires that
specific harmful quantities and rates of penalty be
promulgated, definite numerical differences between
categorie3 must be determined.
Modification of the IMCO System
In light of the foregoing discussion, some modifications of the
IMCO system are required in order to develop a viable methodology
for determining harmful quantities and rates of penalty. The
following required modifications have been identified.
• Hazardous materials which have already been profiled
and categorized must be reexamined in terms of their
freshwater hazard potential.
• Unprofiled and uncategorized hazardous materials must
be evaluated for both fresh- and saltwater hazard
potentials. The guidelines contained in Appendices
E and F form the basis for this work.
• Physical/chemical properties (specifically, degradability
and dispersibility) must be taken into account to modify
or adjust the rate of penalty.
• A mechanism for quantitatively differentiating between
the IMCO categories must be devised in order to derive
harmful quantities and rates of penalty.
THE IMCO METHODOLOGY FOR DETERMINING
HARMFUL QUANTITIES AND RATES OF PENALTY
Profiling and Categorization of Hazardous Materials
Under the IMCO Methodology, hazardous materials are profiled
and categorized in two separate ways. The first profile is in
strict accordance with the IMCO system and results in a charac-
terization of the relative hazard potentials associated with each
material. The IMCO/GEsANP guidelines for the profiling of
hazardous materials are contained in Appendix E. Individual
profiles of materials considered by this study are contained in
Appendix G.
Based on the profiles generated in Appendix E, the hazardous
materials were assigned to hazard categories. The IMCO/GESAMP
guidelines for categorizing hazardous materials are contained in
Appendix F. Appendix G shows the category to which each hazardous
material was assigned as well as the basis for assignment to that
category. Appendix H lists hazardous materials by category.
11—74
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The profiling operation considers the bioaccumulative, toxi-
cological, irritant, and aesthetic properties of the hazardous
material in terms of the level of hazard associated with each
material under each of the five hazard potentials. As such, the
system provides guidelines for quantitative differentiation
between materials within each profile heading but not across
profile headings. This means that within each of the five
hazard potential categories (see Appendix E) clear-cut guide-
lines have been established for identifying the relative magni-
tude of the particular hazard for any given material. For
example, the potential to damage living resources is assessed
on the basis of 96 hour LC 50 . Materials having mean 96 hour
aquatic toxicities of 1 ppm or less are considered to be highly
toxic while materials with 96 hour LC 50 1 s ranging between 1 and
10 ppm are considered moderately toxic. Although the selection
of these ranges was somewhat arbitrary, it is still possible to
assign appropriate ratings to each material on the basis of
known “numbers” (e.g., 96 hr LC 50 1 s, LD 50 1 s), and because these
ratings are numerical in nature, various means of quantitative
comparison are possible. On the other hand, when comparing
across hazard potentials (e.g., bioaccumulation versus moderate
damage to living resources), one is faced with comparing unre-
lated factors. More precisely, there exists no reasonable conunon
denominator which allows one to compare or relate the various
hazard potentials in a quantitative and rigorous fashion.
Because of this problem, the IMCO and GESAMP experts were forced
to resort to certain value judgments in order to devise a system
which grouped hazardous materials with the recognized capability
of exerting multiple hazard effects. These value judgments are
manifest in the definitions of the four hazard categories contained
in Appendix F. Referring to this appendix, the reader will see
that in Category A, for example, a value judgment has been made
which says that hazardous materials which are either bicaccumulated,
highly toxic to aquatic life, or tainting and moderately toxic to
aquatic life pose the same relative degree of hazard. Thus in
accepting the IMCO based methodology, one must accept these value
judgments which are an integral part of the IMCO system. It
should be noted that these value judgments were affected by a
variety of international interests including environmental,
scientific, commercial, political, economic, and social at the
1973 convention.
The second profiling operation in this phase was based on the
physical/chemical properties of the hazardous materials. This
was necessary because the IMCO rating system affords little
recognition to these properties which in many instances can have
a substantial effect on the ability of the hazardous materials
to exert their full hazard potential. More precisely, the IMCO
system, by itself, provides a “worst case” assessment of the
11—75
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hazards associated with various materials. This is an unavoid-
able consequence of the data base for this system (e.g., 96 hr
LC 50 1 s, LD 50 1 s, bioconcentration factors). However, in a spill
situation the ability of a given hazardous material to exert its
full hazard potential is constrained by the degree to which it
is able to reach and persist in the critical areas of the
environment.
As a first step in determining the degree to which the physical/
chemical properties of hazardous materials affect their hazard
potential it was necessary to profile the materials in a manner
which would indicate their general pattern of action following
a spill into a natural water body.
Four properties were selected as being the most meaningful in
terms of predicting general action patterns:
• Persistence
• Behavior Classification (Float, Mix, Sink)
• Volatility
• Solubility
These properties are most precisely defined in Appendix I.
In Appendix G, each material is profiled with respect to
these four properties. The full significance of these pro-
files is explained in the next section.
Quantifying Differences Between Hazard Categories and
Physical/Chemical Characteristics
The proposed IMCO regulations 2 provide guidelines for the
operation of ships engaged in the transport of hazardous mate-
rials. In this respect, the differences between the four IMCO
categories are functionally defined in terms of the degree to
which operating restrictions are placed on the carriers. However,
this type of differentiation is not adequate for determining
harmful quantities and rates of penalty. Rather a more quanti-
tative form of differentiation is required.
In this study the four IMCO hazard categories (A through D)
were differentiated on the basis of critical concentration.
Each category was assigned a critical concentration based on
the mean aquatic toxicity (96 hr LC5Q) range representative of
that category (see Appendix F). Critical concentrations for
each category are given in Table V-i.
11—76
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TABLE V—i
IMCO CATEGORY CRITICAL CONCENTRATIONS
IMCO
Category
A
B
.
C
D
Representative
Aquatic Toxicity Assigned Critical
Range (ppm) Concentration (ppm )
<1 0.5
1-10 5.5
10—100 55
i00 500* 300
*The IMCO criterion for Category D aquatic toxicity is
96 hr LC 50 values of 100 l000 ppm. The selection criteria
for materials considered in this study eliminated any
material with a 96 hr LC 50 in excess of 500 ppm. Thus, the
representative toxicity range for Category D materials has
been changed to 100-500 ppm for use in this study.
The primary reasons for selecting aquatic toxidity as the basis
for differentiating between hazard categories is that it is the
only criterion common to all four categories and, therefore, the
only one which permits a quantitative comparison of categories
without some form of additional subjective evaluation between
different hazard potentials (e.g., bioaccumulation vs reduction
of amenities). Furthermore, the aquatic toxicity data along with
the oral toxicity data is the most coI iplete and best documented
set. However, the oral toxicity data (primarily derived from
animal studies) is only indirectly applicable since it is used
to approximate the threat to man through oral ingestion. The
aquatic toxicity data, on the other hand, is directly applicable.
Finally, in the vast majority of spills, the most probable and
observable damages will be in terms of fish-kill or some other
form of damage to aquatic life.
As alternatives to selecting the mean value of the aquatic toxicity
range for each category, mean, median, and modal values of the
materials comprising each category were also considered for
determining the critical concentrations of each category. All
of these alternatives were rejected. From an operational point
of view, any of these alternatives would require the recomputation
of the critical concentration every time a new material was added
to the category. This in turn would necessitate a recomputation
of the harmful quantity and a subsequent adjustment of the rate
of penalty. Moreover, in light of the wide variations encountered
11—77
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in the aquatic toxicity data, it is unreasonable to expect that
by utilizing these median, modal or average values any meaning-
ful enhancement of the category’s critical concentration would
be realized.
The second profiling operation (Appendix G) characterized the
hazardous materials on the basis of their physical/chemical
properties. This was done as a first step in attempting to
answer a very important,, though rather intractable, question
common to all methodologies:
To what extent does the dispersibility and degradability
of a given hazardous material reduce or enhance its
ability to e,cert its full potential?
A precise determination of the answer to this question, even
for a set of very specific circumstances, is, of course, impos-
sible because of incomplete understanding of the environment
and the forces acting therein. When extended to the qeneral
case (e.g., lakes in general vs a specific lake whosephysical,
chemical, biological, and hydrodynamic properties are well
understood), the problem becomes even more difficult. Neverthe-
less, it must be addressed.
The approach taken in the IMCO Methodology was to derive subjective
adjustment factors (on a scale of 0 to 1) which could be assigned
to a material with a given set of physical/chemical properties.
These adjustment factors give recognition to the ability of a
material’s physical/chemical properties to affect its hazard
potential(s) in various water body types and this can be factored
directly into the rate of penalty as a mechanism which accounts
for a material’s dispersibility and degradability characteristics.
The procedure used to obtain adjustment factors was the DELPHI
method. ’ This procedure involves the repeated questioning of
persons knowledgeable in the area of interest in order to obtain
a coalescence of expert opinion. The DELPHI method makes use of
controlled opinion feedback and thus avoids direct confrontation
of the experts with one another. Between rounds of questioning,
the participants are “fed” the results of the previous round and
advised of the opinions which were voiced by other panel members.
In subsequent rounds, the question posed may also be restated in
slightly different terms especially if ambiguities surrounding
the question are causing wide variations in the results. By
repeating this sequence a number of times, a coalescence of
opinion is obtained in an environment o controlled participant
interaction.
‘Dalkey, N. and 0. Helmer. “An Experimental Application of the
DELPHI Method to the Use of Experts,” Management Science ,
Vol. 9, No. 3, 1963.
11—78
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The panel for this DELPHI consisted of a group of scientists
and engineers selected from the staff of Battelle’s Pacific
Northwest Laboratory. This panel was asked to assign a series
of adjustment factors based on their estimation of how various
sets of physical/chemical properties would affect the ability
of a material with these properties to exert a given hazard
potential in a given water body type. The details of this
DELPHI are contained in Appendix I along with a table depicting
the resulting adjustment factors. As will be seen in the “Fine
Determination” section of this chapter, these adjustment factors
are applied to a base rate of penalty in order to obtain a formal
rate of penalty.
Determining the Harmful Quantity
In this metl.odology harmful quantities must be determined for the
four hazard groups in the four water bodies. This means that 16
harmful quantities are generated by this methodology. As in the
other methodologies, a prerequisite to determining a harmful
quantity is the definition of the term “harm.” More precisely,
the harmful quantity determination requires that a threshold
level of harm be defined in such a way that it can be related
quantitatively tc the hazardous materials and their various
hazard potentials. Since each IMCO hazard category is represented
by a critical concentration, the threshold level of harm (or the
criteria for defining harm) must be relatable to the critical
concentration.
The approach taken in this methodology for determining the
threshold level of harm is identical to the Resource Value
Methodology approach. Harm is defined as $5,000 worth of
damages. The rationale for using $5,000 is discussed in
Chapter IV of this report. Having defined the threshold level
of harm in terms of dollars it is then possible to relate this
dollar value to a critical volume of water if the unit value of
water is known.
V critical = $5,000/unit value of water body (V-i)
The harmful quantity is then computed by multiplying the critical
concentration by the critical volume.
Table V-2 contains the IMCO Methodology harmful quantities.
These values were obtained using the critical concentrations
reported in Table V—i in conjunction with the critical volumes
computed from equation V-i. Unit values used for the deter-
mination of critical volume in the four water body types
(derived in Chapter IV) are as follows:
• Lake - $0.07/rn 3 ($83/AF)
11—79
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TABLE V-2
IMCO METHODOLOGY HARMFUL QUANTITIES*
Water Body Type
IMCO
Category Lake River Estuary Coastal Zone
A 3.7xlO kg 3.7x1O kg 2.6xlO kg l.4x1O kg
H 8.3x10 lbs 8.3x10 lbs 5.4x10 lbs 3.lxlO lbs
B 4.lx1O kg 4.lx1O kg 2.7xlO kg l.5xlO kg
8.1 x 10 lbs 9.1 x 10 lbs 6.1 x 10 lbs 3.4 x 10 lbs
C 4.lx10 kg 4.1x1O kg 2.7x1O kg 1.5x1O kg
9.lxlO lbs 9.lxlO lbs 6.lxlO lbs 3.4xlO lbs
D 2.3xlO kg 2.3x10 kg l.5x1O kg 8.5xlO kg
4.9x10 lbs 4.9x10 lbs 3.2x10 lbs l.9x10 lbs
*p mded to two significant figures
-------
• River - $0.07/rn 3 ($83/AF)
• Estuary - $0.10/rn 3 ($127/AF)
• Coastal Zone — $1,511/106 m 3 ($1.84/AF)
It is noteworthy that the IMCO Methodology harmful quantity can
be computed on the basis of any threshold level of harm if this
threshold can be related to the critical volume of water. Since
the definition of harm will, in all likelihood, continue to be a
controversial issue, this degree of flexibility promises to be a
valuable asset in that it allows for the easy recomputation of
harmful quantities while preserving the basic tenets of the
methodology. This versatility is also available in recomputing
the rate of penalty as evidenced in the next section.
Determining the Base Rate of Penalty
The IMCO Methodology bases its rate of penalty on predicted
damages to the environment and follows directly from the harmful
quantity determination in the previous section. Harmful quan-
tities were derived by using a threshold dollar value of $5,000
in conjunction with average present worth values for water body
types and critical concentrations for each category. Using
this rationale, the harmful quantity (HQ) can be viewed as that
amount of material capable of producing $5,000 worth of damages
to the envirc nment. It follows that the rate of penalty should
be set at $5,000/HQ. Since there are 16 harmful quantities,
one for each category in each water body type, 16 rates of
penalty are possible. These rates of penalty are more appro-
priately labeled base rates of penalty as certain modifications
are required to account for the dispersibility and degradability
characteristics before a final rate of penalty can be determined.
These modifications are explained in the next section.
Fine Determination
A step by step procedure for computing fines under the IMCO
Methodology is outlined below.
In this procedure, the fine for a given hazardous material
becomes a function of three variables:
• The quantity spilled,
• The base rate of penalty ($5,000/HQ), and
• The adjustment factor (AF) where $5,000 x AF
is the final rate of penalty.
11—81
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On a conceptual basis, the spiller is being fined for the
predicted damages to the water body ($5,000/HQ) with considera-
tion (AF) given to the ability of the of the spilled material to
exert its various hazard potentials. The three cases (a, b, c)
consider the three situations which can cause a hazardous material
to be placed in a given hazard category. Note that in case b
the final adjustment factor may exceed a value of one. Hence,
materials capable of exerting multiple hazards of the same order
of magnitude (same category) will in most instances receive
higher rates of penalty.
The procedure for determining fines under the IMCO Methodology
is as follows:
1. Determine the name and quantity (M) of hazardous material
spilled.
2. Determine the type of water body (w 1 ) into which the
hazardous material was spilled.
3. Determine the hazard category (hc ) of the material from
Appendix G.
4. Determine the hazard potential(s) (ck) which caused the
material to be placed in hazard category (hc 3 ). This is
also determined from Appendix G.
5. Determine the physical/chemical characteristics (pc 1 ) of
the material from Appendix G.
6. Determine the adjustment factor(s) [ AF(w , ck, pci)]
by entering the table in Appendix I with the hazard
potential(s) (ck), water body type (Wj), and physical/
chemical characteristic (pd).
7. Determine the harmful quantity [ HQ(w , hc)] for the
material in water body type (Wj). Consu1 Table V-2
for this number.
8. Compute the fine from one of the following formulas:
a) If there is only one hazard potential (ck) which
caused the material to be placed in hazard category
(hc ) then
Fine = M x [ $5,000/HQ ] x [ AF ]
(w 1 , hc ) (w 1 , pc 1 )
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b) If there is more than one hazard potential (ck)
in Appendix G which by itself could cause the
material to be placed in hazard category (hc.j)
then
Fine = M x [ $5 ,000/HQ(w. ck, pc i) 1 x [ AF Ck pci)]
and n is the number of hazard potentials which, by
themselves, could cause the material to be placed
in category (hc ).
c) If the material was placed in category (hcj) as a
result of the additive effects of various hazard
potentials any one of which by itself is insuff i-
cient to cause the material to be placed in the
category then
Fine=Mx [ $5,000/HQ I X [ AF c c
(w 1 , hc 1 ) k=l i’ k’ p 1
n
where n is the number of hazard potentials which,
when considered together, caused the material to
be placed in category (hcj).
Final rates of penalty for each hazardous material have been
computed in Appendix M.
Sample Calculations
Sample fine calculations for three hazardous materials in three
water body types are provided below:
Case 1 — Acetaldehyde spilled into a lake
Material: acetaldehyde
Water body type: lake
Hazard category: C
Hazard potential which
caused it to be placed
in Category C: damage to living resources
11—83
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Physical/chemical
characteristics: nonpersistent, floats, volatile, soluble
Adjustment factor: 0,3
Harmful quantity:
4.1 x lo 3 kg
(9.0 x lO 3 lbs)
$5,000 x 0.3 = $366
4.1 x iO kg io kg
$165
x 0.3 = ______
lbs
= $5,000
9.1 x lbs
Case 2 — Cadmium sulfate spilled into a river
Material: cadmium sulfate
Water body type: river
Hazard category: A
Hazard potential which
caused it to be placed
in Category A: bioaccumulation
Physical/chemical
characteristics: persistent, sinks, soluble
Adjustment factor: 0.8
Harmful quantity:
3.7 x 101 kg
8.2 x 101 lbs
=
Rate of penalty x 0.8 = $108/kg
37 kg
Case 3 - Phenol spilled into an estuary
Material: phenol
Water body type: estuary
Hazard category: B
Hazard potential which
caused material to be
placed in Category B: tainting (bioaccuinulation)
Rate of penalty =
— $5,000 x 0.8 = $48/lb
— 83 lbs
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Physical/chemical
characteristics: nonpersistent, mixes
Adjustment factor: 0.45*
Harmful quantity: 2.7 x 102 kg
5.9 x 102 lbs
Rate of penalty = $5,000 x 0.45 = $84710 kg
2.7 x 102 kg
$5,000 — $38
6.1 x 10 lbs
Harmful quantities and rates of penalty as determined by the
IMCO Methodology for designated hazardous substances are tab-
ulated in Appendix M. It is apparent that if the economic
rational is to be maintained, penalty rates must be reviewed
periodically and adjusted to reflect changes in resource
values and/or monetary fluctuations.
*Since no adjustment factor was determined for nonpersistent
“bioaccuznulation” materials, an adjustment factor of 0.45
based on aquatic toxicity was used because of its similarity
of action to tainting.
11—85
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REFERENCES
1. “Report of an Ad Hoc Panel of IMCO and GESAMP Experts
to Review the Environmental Hazards of Noxious Substances
Other Than Oil Transported by Ships,” Joint Group of
Experts on the Scientific Aspects of Marine Pollution,
London, England, 1972/73.
2. “RegulatiOns for the Control of Pollution by Noxious
Liquid Substances in Bulk, Annex II, ” International
Conference on Marine Pollution, October 31, 1973.
3. Public Law 92—500 and 92nd Congress of the United States,
October 18, 1972.
4. Dalkey, N. and 0. Helmer, “An Experimental Application of
the DELPHI Method to the Use of Experts,” Management
Science , Vol. 9, No. 3, 1963.
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VI. THE UNIT OF MEASUREMENT METHODOLOGY
BRIEF
The methodology developed below is a variation of the IMCO
Methodology discussed in the previous chapter but more impor-
tantly it represents a radical conceptual departure from the
other methodologies.
This methodology is intended to satisfy the letter of the law
(Section 311) whereas the other methodologies in this report
utilize a technical or economic basis to satisfy the intent
of the law. The derivation of this methodology is based upon
the selection of a unit of measurement. Harmful quantities
and rates of penalty are then derived from this unit of measure-
ment whose prime selectipn criteria are that it (1) be a unit
common to usual trade practices, and (2) be large enough so
that spillage of this quantity leaves little doubt that sub-
stantial harm will result. Rates of penalty are also derived
from this unit of measurement by forming a ratio with the
fixed monetary amount set by Congress in Section 311. Hence,
the emphasis in this methodology is away from the concepts of
a harm threshold and costs relatable to an economic or techni-
cal basis and toward a system whose units are more in line with
trade practices and the letter of the law.
For purposes of identification, this methodology will be
referred to hereafter as the Unit of Measurement (UM) Method-
ology. Figure VI-l provides a schematic representation of the
UM Methodology which should facilitate reader understanding
of ensuing sections.
METHODOLOGY RATIONALE
In the other methodologies, an attempt has been made to develop
systems that derive harmful quantities arid rates of penalty in
a logical and relatively rigorous sequence of steps after
certain necessary simplifying assumptions have been made. For
example, the approach to determining substantial harm has been
one of defining a threshold of harm either statistically or
pragmatically, relating this threshold to a volume of water,
and then deriving the harmful quantity by calculating the amount
of a given hazardous material required to contaminate this
volume to its critical concentration. Similarly, rates of
penalty have been derived as entities in themselves either on
the basis of prevention costs or the value of the resource
potentially damaged. Conceptually, both of these derived rates
of penalty have direct economic meaning in that the ratio formed
by the dollar value (X) and the mass of pollutant spilled (Y)
are functionally related. For example, when the cost of preven-
tion is employed, the basic rate of penalty is set at a level
11—87
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DES IGNATED
HAZARDOUS
MATERIALS
I’PROFILED USING1 PROFILED ON BASIS1
I IMCOIGESAMP OF PHYSICAL!
[ _ SYSTEM CHEMICAL PROP ER ]
CATEGORIZED
ON BASIS OF
HAZARD PROFILE BASE UNIT
I OFMEASUREMENT
r “ AND HARMFUL
ICRITI CAL CONCENTRATION QUANTIn’ ASS IGNEI
I DETERMINED FOR TO CATEGORY “D”
EACH CATEGORY MATERIALS
Ii Ir ____
HARMFUL QUANTITY I UNIT CF MEASUREMENT1
COMPUTED FOR COMPUTED FOR
CATEGORY ‘*“ I CATEGORY “A” THRU “C”
THRU”C”MATERIALS L MATERIALS
HARMFUL QUANTIT I E
ROUNDED TO
COMMON TRADE
UNITS
WATER BODY FIXED MONETARY
TYPE I AMOUNT ($1( )-1OOO)
L FROMLAW
II PHY CALJCHEMUAL I _________
______ [ !FA Y1
L_4 HAZARD TYPE I
I _ JFINAIRATES1
I C I PENALTY
LDETERMI NED
FIGURE VI-1. FLOW DIAGRAM FOR UNIT OF MEASUREMENT METHODOLOGY
11—88
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deemed necessary to provide adequate economic incentive for the
institution of spill prevention measures. Theoretically, X
dollars expended result in a reduction of spillage equal to Y.
Similarly, the Resource Value Methodology produces a rate of
penalty equal to the value of damages incurred and thus inter-
nalizes the cost to society of spillage. The spillage of Y
units of hazardous material results in X dollars worth of
damages, this amount being reimbursed to society through the
fine system.
The UM Methodology departs significantly from other approaches
in two important conceptual areas. First, the harmful quantity,
previously derived from a threshold concept, is herein equated
to a base unit of measurement which is selected large enough
so that there is little doubt that spillage of this amount will
result in substantial harm. Thus, on the spectrum of possible
harmful quantities, a point is selected to yield a harmful quan-
tity which is no less than (but possibly greater than) the quan-
tity which actually does produce substantial harm when spilled
into a water body.
The second area of major departure is in selection of the basis
for the rate of penalty. As discussed previously, the UM Method-
ology merely selects a unit of measurement based on trade prac-
tices and relates it to the monetary amount fixed by Congress.
In this respect, the methodology is supported by the wording of
the law:
“The Administrator shall establish by regula—
lation, for each hazardous substance designated
under subparagraph (A) of this paragraph, and
within 180 days of the date of such designation,
a unit of measurement based upon the usual trade
practice and, for the purpose of determining the
penalty under clause (iii) (bb) of this subpara-
graph, shall establish for each such unit a fixed
monetary amount which shall be not less than
$100 nor more than $1,000 per unit. He shall
establish such fixed amount based on the toxicity,
degradability, and dispersal characteristics of
the substance.”
Public Law 92—500, Section 311(b) (2) (B) (iv)
Indeed, this paragraph strongly implies that the rate of penalty
be derived by forming a ratio between a unit of measurement
based on usual trade practices arid the fixed monetary amount
($l00-$l,000) specified by Congress.
The UM Methodology is similar to the other methodologies in the
terms of the procedures used to differentiate between hazardous
materials on the basis of toxicity, degradability, and dispers—
ibility. Here the inputs used to make these differentiations
11—89
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will be the same as those described in the discussion of the
alternative approaches (e.g., 96 hr LC 50 , LD 50 ). Since this
discussion is primarily illustrative, the authors have simply
extracted the IMCO procedures for making this differentiation
rather than developing a completely unique set of guidelines.
The IMCO procedures were selected on the basis of their com-
patibility with the low levels of resolution inherent in the
UM approach.
UNIT OF MEASUREMENT AND HARMFUL QUANTITY DETERMINATION
Referring to Figure Vi—1, one can see that the initial steps in
the UM Methodology are identical to those of the IMCO Methodology.
Hazardous materials are profiled and assigned to one of four
hazard categories on the basis of their various hazard potentials.
A critical concentration is then assigned to each hazard category.
Concurrently, the hazardous materials are profiled on the basis
of their physical/chemical properties. This step is required in
order to be able to assign an adjustment factor to each material
in the final fine determination step.
The next step, and also the point of departure from the IMCO
Methodology, is the selection of a base unit of measurement.
Understandably, this selection can be rather arbitrary since the
condition which the unit of measurement must meet is that it be
a unit “common to the usual trade practice.” For purposes of
this illustration, the authors have chosen to select the unit of
measurement from a group of common containers used in the trans-
portation of hazardous materials. Figure VI-2 portrays some of
the more common container sizes used by industry to ship hazardous
materials. Viewing this figure, one can see that the containers
fall into two basic groups: small individually packaged units
such as metal cans and drums, and larger bulk shipment containers
such as tank trucks and barges. One can also observe that there
is a significant break (in terms of quantity) between the two
groups with the largest individual container being a 110 gallon
metal drum and the smallest bulk container being a 4000 gallon
tank truck. This break provides a convenient point of demarca-
tion for establishing a unit of measurement and a harmful quantity.
If one considers IMCO Category D materials, which are character-
ized as being recognizably hazardous, one would probably be hard
pressed to show that the spillage of 110 gallons (the largest
packaged container size) of such material would result in sub-
stantial harm. However, one would expect almost unanimous agree-
ment as to the ability of 4000 gallons of a Category D material
to produce substantial harm in many spill situations. To verify
this assertion, consider the spillage of 4000 gallons of formic
acid (a Category D material) into a freshwater lake or river.
The volume of water (V critical) potentially affected is deter-
mined as follows:
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GALLONS
10 100 1000 10, 000 100,000
!IIJIJI I I II III 1 I IJII II I IJI!II I
BARGE
METAL CAN METAL DRUM RAIL TANK CAR
I 4 I
CLASS CAR6OY ‘ I
I- I ____
TANK TRUCK
BO1TL.ES
H
H
I I I I —I——————f I I I
HEAVY DUTY
PAPER BAGS
I I
FIBER BOXES OR CARTONS
______________________ CLOSED HOPPER
CAR
I I
FIBER AND METAL
BARRELS
I I iliiiii I I 1111111 I I iIiiii I I 1111111 I
10 100 1000 10, (300 100,000
POUNDS
FIGURE VI-2. COMMON HAZARDOUS MATERIAL CONTAINERS
-------
Assumptions:
Spill size = 4000 gal of 90% formic acid (S.G. = 1.22)
Freshwater critical concentration = 175 ppm (24 hr TLm
for bluegill)
The mass of pollutant spilled is
4000 gal x 1.22 x 8.34 lbs X .9 = 1.65 x l0 kg
The volume potentially contaminated is
1.65 x 10 k kg — 7
V critical = I 75 x 102 mg79 . . x 10 9..
or
V critical 9.4 x l0 9.. = 3.32 x 106 ft 3 = 76 acre—feet
or
V critical = a 7.6 acre lake with an average depth of
10 feet or a 6.3 mile long plug in a river
with a cross-sectional area of 100 ft 2 .
Thus by defining substantial harm as the spilling of 4000 gallons
of a Category D material, a harmful quantity is set for which
there is a high probability that the spillage of such a quantity
results in substantial harm although it is possible that spillage
of a smaller amount could also produce substantial harm. Further-
more, by using this approach harmful quantities can be designated
in units which are common to the usual trade practice for Category
D substances. As shown below, harmful quantities for the remain-
ing categories of hazardous substances can be similarly designated.
Table VI-l lists the critical concentrations assigned to each
IMCO category. By forming a ratio of the critical concentrations
of Category A through C materials to the critical concentration
for Category D materials, a numerical factor can be obtained
which reflects the ability of hazardous materials in the first
three categories to contaminate natural waters relative to
Category D materials. Hence, harmful quantities and units of
of measurement can be assigned to the Categories A through C
materials by simply multiplying these numerical factors by the
base unit of measurement/harmful quantity previously selected for
Category D materials.
Since harmful quantity is a threshold reporting function, it is
advisable to round of f the computed values to units that are more
11—92
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TABLE VI-1
CALCULATION OF UNITS OF MEASUREMENT AND
HARMFUL QUANTITIES FOR IMCO CATEGORIES
Critical Ratio of Critical Concen- Calculated Unit of Mea— Calculated* Unit of Mea-
IMCO Concentration tration to Category D sur sent and Harmful sur nent and Harmful
Category ( p m ) Critical Concentration Quantity (Volume) Quantity (Mass )
Iii
‘ .0 A 0.5 .0016 24.23 t 24.23 kg
6.40 gal 53.41 lbs
B 5.5 .0183 277.1 £ 277.1 kg
73.2 gal 610.9 lbs
C 55.0 .1833 2,770 £ 2,770 kg
732 gal 6,107 lbs
D 300.0 1.0000 15.142 £ 15,142 kg
4,000 gal 33,382 lbs
*Ca lcuJated assuming an average specific gravity of 1.
-------
easily ascertained in a spill situation. Table VI—2 contains
the recommended harmful quantities for the four IMCO categories.
Rounding was performed in the English system and metric equivalence
computed from the rounded English numbers.
TABLE VI-2
RECOMMENDED HARMFUL QUANTITIES
IMCO Harmful Quantity Harmful Quantity
Category ( volume) ( mass )
A >5 gal >50 lbs
>18.93 2, >22.7 kg
B >55 gal >500 lbs
>208.20 9, >227 kg
C >550 gal >5000 lbs
>2081.98 2 >2267.96 kg
D >4000 gal >16 tons
>15.41 m 3 >14.5 MT
COMPUTING THE BASE RATE OF PENALTY
In the UM Methodology, the base rate of penalty is determined
from the ratio formed by the unit of measurement computed in
Table VI-l (Column 3) and a dollar amount of $1000. The ($1000)
upper limit of the dollar range ($100-$1000) specified by
Congress was selected because, as will be seen in the next
section, in most instances the adjustment factors* for dispers —
ibility and degradability are proportioned to reduce the base
rate of penalty up to one order of magnitude (0.1-1.0). The
base rates of penalty for the UM Methodology are computed using
equation VI-1 and are summarized in Table VI-3.
Fine Determination
The step by step procedure for computing fines under the tJM
Methodology is outlined below.
In this procedure, the fine for a given hazardous material
becomes a function of three variables:
• the quantity spilled (M)
• the base rate of penalty ($1000/unit of measurement)
• the adjustment factor (AF)
*Identical to IMCO Methodology adjustment factor (see Appendix I)
11—94
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Base Rate Of Penalty = computed Unit of I 1easurernent (v11)
(Table VI-l)
where (Base Rate of Penalty) x AF is the final rate of penalty.
TABLE VI-3
BASE RATE OF PENALTY
IMCO Base Rate of Base Rate of
Category Penalty (volume) Penalty (mass )
A $410/b 2 $410/10 kg
$156/gal $186110 lbs
B $360/100 9. $360/100 kg
$136/lO gal $163/100 lbs
C $360/1000 $360/l000 kg
$ 136/100 gal $163/1000 lbs
D $661/10 m 3 $661/10 MT
$250/bOO gal $600710 tons
As in the IMCO Methodology, adjustment factors (AF) derived from
the DELPHI technique (Appendix I) are applied to the base rate
of penalty to yield a final rate of penalty. These adjustment
factors account for the degradability and dispersal characteristics
of a given hazardous material by considering the degree to which
its physical/chemical properties affect its ability to exert a
given hazard potential(s) in a given water body type. In most
instances the adjustment factor tends to reduce the base rate of
penaltY. Adjustment factors are assigned to each material on the
basis of its physical/chemical profile in Appendix G.
Thus, in the UM Methodology, the discharger is being fined at
the rate Of penalty with consideration given to the effects of
the spilled material’s physical/chemical properties. The
three cases (a, b, c) consider the three different ways a
hazardous material can be placed in a given hazard category.
11—95
-------
Note that in case b, additive effects (multiple hazard potentials
of the same order of magnitude) can cause the adjustment factor
to exceed a value of one. The procedure for computing fines
under the UM Methodology is as follows:
1. Determine the name and quantity (M) of hazardous material
spilled.
2. Determine the hazard category (hc 1 ) of the material from
Appendix G.
3. Determine the base rate of penalty from Table IV-3.
4. Determine the type of water body (wi) into which the hazardous
material was spilled.
5. Determine the hazard potential(s) (ck) which caused the
material to be placed in hazard category (hc ).
6. Determine the physical/chemical characteristics (pc 1 ) of the
material from Appendix G.
7. Determine the adjustment factor(s) (AF(w 1 , ck, pci)) by
entering the table in Appendix I with the hazard potential(s),
(ck); water body type, (Wj); and physical/chemical charac—
teristics, (pd).
8. Compute the fine from one of the following formulae:
a. If there is only one hazard potential (ck) which
caused the material to be placed in hazard category
(hCj) , then
Fine = M x (Base Rate of Penalty) x fAl” (w c )
jfCklpl
b. If there is more than one hazard potential (ck) in
Appendix G which by itself could cause the material
to be placed in hazard category (hcj), then
Fine = M x (Base Rate of Penalty) x J c c )
Lk=l ‘ i’ k’ 1
and n is the number of hazard potentials which, by them-
selves, could cause the material to be placed in hazard
category (hc 1 ),
11—96
-------
c. If the material was placed in category (hc 1 ) as a result
of the additive effects of various hazard potentials,
any one of which by itself is insufficient to cause
the material to be placed in the category, then
1
Fine = M x (Base Rate of Penalty) x IE AF 1
Lk=l W.,Ck,pCl
n
where n is the number of hazardous potentials which, when
considered together, caused the material to be placed
in category (hcl).
Final rates of penalty for each hazardous material have been
computed and are included in Appendix N.
SAMPLE CALCULATIONS
Sample calculations for three hazardous materials in three water
body types are performed below.
Case 1 - Acetaldehyde in a lake
Material: acetaldehyde
Water body type: lake
Hazard category: C
Hazard potential which caused it to be
placed in Category C: damage to living resources
Physical/chemical characteristics:
non—persistent, floats, volatile, soluble (liquid)
Adjustment factor: 3
$360 $108
Rate of penalty = 1000 2. x • = 1000 9.
= $136/100 gal x .3 — $41/100 gal
Case 2 - Cadmium sulfate in a river
Material: cadmium sulfate
Water body type: river
Hazard category: A
11—97
-------
Hazard potential which caused material
to be placed in Category A: bioaccuxnulation
Physical/chemical characteristics:
persistent, sinks, soluble
Adjustment factor: 0.8
$410 $328
Rate of penalty 10 kg X .8 = 10 kg
— $190 8 — $152
_lO lbsX lOibs
Case 3 - Phenol in an estuary
Material: phenol
Water body type: estuary
Hazard category: B
Hazard potential which caused material
to be placed in Category B: tainting (bioaccumulation)
Physical/chemical characteristics:
non—persistent, mixer (90% solution)*
Adjustment factor: •45**
Rate of penalty = x 45 = $162
— $136 — $61
logalX l oga l
*In computing the fine for the spillage of a 90% solution phenol
the rate of penalty would be multiplied by 0.9 to account for
the fact that pure phenol was not spilled.
**Since no adjustment factor was determined for non—persistent
“bioaccumulative” materials, the adjustment factor of 0.45
based on aquatic toxicity was used because of its similarity
of action to tainting.
11—98
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VII. DOHM METHODOLOGY
BRIEF
The methodology developed within this portion of the study is
an extension of an approach formulated by the Division of Oil
and Hazardous Materials (DOIIM), U. S. Environmental Protection
Agency, for assessing the impacts of hazardous material spills
in streams. This approach uses a simplified plug flow model
to assess the quantity of a hazardous material (harmful quantity)
which when spilled is capable of inflicting substantial harm
to key aquatic organisms in a stream. The wide applicability
of Section 311 requires that harmful quantities for other types
of water bodies such as lakes, estuaries, and coastal zones be
determined. To this end, the basic DOHM plug flow model has
been extended and modified whenever possible to meet these
requirements.
In the following discussion, each of the four basic water body
types (streams, lakes, estuaries, and coastal zones) is considered
separately. The aim is that of defining a critical volume, the
contamination of which results in substantial harm. For the
stream and estuary categories, statistical samples of U. S.
water bodies were analyzed to determine this critical volume.
Simplified plug flow models of these water bodies were then
used to determine harmful quantities based on the amount of
hazardous substance required to bring the critical volume to
the critical concentration level. Harmful quantities for lakes
and coastal zones were extrapolated from the stream and estuary
harmful quantities, respectively.
Naturally, the use of a plug flow model to characterize such
hydrodynamically complex water bodies as streams and estuaries
requires a number of simplifying assumptions. That these
simplifying assumptions detract from the precision of the method-
ology is, of course, recognized by the authors and an attempt
to compensate for the discrepancies that arise between the models
and the natural environment has been made in the form of an adjust-
ment factor.
Determination of the rate of penalty is independent of that of
the harmful quantity in the DOHM Methodology. For this approach,
the rate of penalty is equated to the cost which would have been
incurred by the discharger had he instituted measures to prevent
the spill.
Separate “costs of prevention” have been determined for both
stationary and mobile sources. The latter includes transportation
by rail and barge. Data from sources in the trucking industry
indicates that greater than 95 percent of spills occur at
11—99
-------
transfer sites and, therefore, are largely stationary source
occurrences.’ In order to facilitate the development of cost
of prevention projections, a prevention technique was selected
for each potential source and cost data developed for this
technique. The technique’s effectiveness in preventing the
occurrence of spills was then analyzed in order to develop an
estimate of the quantity of material prevented from being
spilled. The base level cost of prevention was determined by
taking the ratio of the cost of prevention to the quantity of
material prevented from being spilled.
A method is presented for employing the cost of prevention to
derive the rate of penalty. The base level cost of prevention
can be utilized directly as the penalty rate or an adjustment
factor can be utilized to vary the cost of prevention as a
function of chemical characteristics of each substance. This
latter variation recognizes that differences exist in potential
levels of harm which can be inflicted by different substances
and that higher levels of prevention (more costly) should be
justified to reduce the possibility of spills of more hazardous
substances.
Figure VII—l represents the flow diagram of the procedure
required by the DOHM Methodology to develop a harmful quantity
and rate of penalty for any substance. The following sections
provide detailed explanations of the steps identified in the
diagram.
HARMFUL QUANTITY DETERMINATION
Stream Model
The DOHM 2 stream model assumes that a hazardous material is
spilled into a stream over a finite period of time, that it
mixes instantaneously to a uniform concentration equal to the
critical concentration, and that the plug formed by the spilled
material proceeds downstream without being subjected to further
dissipation by hydrodynamic forces. Thus, for a given critical
concentration, the time of exposure at any point in the stream
is a function of the spill size and the flow rate of the stream.
Mathematically, this can be written as
T = KM/CQ (VII-l)
1 U. S. Department of Transportation, Office of Hazardous Materials.
“Reports of Spills of Hazardous Substances: Computer File,” as
abstracted by Mr. Robert Reese, National Tank Truck Carriers,
Washington, DC.
2 U. S. Environmental Protection Agency, Division of Oil & Hazard-
ous Materials. “The DORM Approaches,” Annex to REP WA74-R064,
distributed at Bidder’s Conference, November 6, 1973.
11—100
-------
INCLUSION
CHARACTERISTICS
INTO MODIFYING
FUNCTION REFLECTING
THE MATERIAL’S
HAZARD POTENTIAL.
ANALYSIS
OF PPLICAT 1ON
TIME-DOSE FACTOR
MORTALITY SELECTION
RELATIONS
MODEL
APPLICATION
TO DETERMINE
HARMFUL
QUANTITY
HARMFUL
QUANTITY
FIGURE Vu-i. FLOW DIAGR1 M FOR DOHM - COST
OF PREVENTION METHODOLOGY
IDE N TI F IC A 110 N
OF THE
HAZARDOUS
MATERIAL’ S
CHARACTERISTICS
(SOLUBILITY
DISPERSION,
TOXICITY)
SELECTION OF
STATIONARY OR
MOBILE
SOURCE PREVENTION
COSTS
ASSIGNMENT
OF CRITERIA
FOR WATER
BODY QUANTITY
DETERMINATION
11—101
-------
where
T = time for the plug to pass a point in the stream (hrs),
M = mass of pollutant spilled (kg),
Q = stream flow rate (m 3 /sec),
C = critical concentration (mg/i), and
K = constant (hr-mg-rn 3 /sec—kg-l)
This expression may be rewritten as:
M TCQ/K (vII—2)
The above expression can be used to determine the harmful
quantity (M = HQ) when the following operations are performed.
• A functional relationship between T and C must be
derived relating the critical concentration (C) to a
time of exposure (T) over which the receptor must be
exposed to the plug for substantial harm to occur
(assuming a stationary receptor, this implies that T
is also equivalent to the time of passage for the
plug); and
• The flow rate (Q) must be defined at a level sufficient
to imply that harm to aquatic organisms in a stream of
that flow or greater is considered substantial to the
environment.
Since in this study the critical concentration has been taken
to be the 96 hr LC 50 for a median sensitive receptor, the only
meaningful time of passage of the plug (T) is automatically
fixed at 96 hours, since a stationary receptor will be exposed
for 96 hours while the plume passes by —- leading edge to
trailing edge. In reality, the time of passage of a plug of
spilled hazardous material can vary substantially; however,
within the range of reasonable spill duration there is a time
of passage which, when combined with its associated critical
concentration, yields a minimum harmful quantity in that ranged
This minimum harmful quantity (the smallest quantity required
to produce substantial harm) is not necessarily the one derived
from the 96 hour plug. In the next section an application
factor is derived which can be used to determine this minimum
harmful quantity. It is important to note that even smaller
harmful quantities may be derived with times of passage outside
the range of interest. Therefore, the minimum referred to here
is a minimum only in the range of interest.
11—102
-------
Derivation of the stream flow rate (Q), representing substantial
harm to the environment is done statistically in the section
entitled “Stream Quantity Determination.”
Application Factor
It is obvious that when 96 hour LC 50 data are employed in the
plug flow model described above, substantial harm can only be
defined as exposure of the aquatic population to the concentration
level equivalent to the 96 hour LC 50 for a period of 96 hours
or more. Intuitively, however, one can envision a situation
requiring less time to pass could lead to equivalent levels of
damage. The situation is illustrated in Figure VII-2. Time of
passage is the same as the time of exposure (relation 1). Critical
concentration is related to time of exposure in an inverse manner
(relation 2). Since harmful quantity is proportional to the pro-
duct of these factors, the harmful quantity curve is equivalent
to the sum of the other curves when plotted on a log-log grid
(relation 3). This forms a characteristic minimum. Hence, given
a particular time—dose mortality relation, there is a unique time
of passage for the contaminated plug which when employed in the
plug flow model will result in the smallest harmful quantity, all
other factors remaining equal. Similarly, within the time range
of direct interest, there is a unique time associated with the
smallest harmful quantity that can be derived in that time range.
These two quantities will not necessarily coincide. Therefore,
before the minimum is located, it is first necessary to define
the time of passage range of direct interest to this study. That
is, what time of passage range is repr esentative of most hazardous
material spills.
Ideally, the appropriate time range would be selected from
historical spill data. unfortunately, the data base for such
an analysis is nonexistent at this time. Only recently have
efforts been made to routinely report spills, and reports rarely
include an estimation of the time of travel for the plug to pass
a stationary point. This omission reflects the difficulty of
making such an observation without sophisticated analytical
equipment available, and an understandable tendency to yield
higher priority to on-scene safety precautions and damage
mitigation activities.
In the absence of historical data on time of passage for the
contaminated plume, an attempt has been made to correlate
available data on duration of fish kills and subsequently estimate
the time of passage based on the apparent time of exposure of the
receptor. The rationale for such a correlation has been dis-
cussed previously in Chapter III in the section dealing with
selection of critical concentrations.
Fish kill duration data reported for the years 1960-1972 have
been reviewed and are plotted in accumulative probability form
11—103
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TIME-DOSE MORTALITY RELATIONSHIP
TIME OF PASSAGE (T) VS
TIME OF EXPOSURE (te)
(RELATION 1)
TYPiCAL LC 50 TIME-DOSE RELATIONSHIP
(RELATION 2)
FIGURE VII-2.
LOG EXPOSURE TIME (te)
RELATIONSHIPS BETWEEN HARMFUL QUANTITY, TIME
OF PASSAGE AND CRITICAL CONCENTRATION
HARMFUL QUANTiTY (HO) VS TIME OF
HO a TXC
HENCE
LOG HQ a LOG 1 + LOG C
(RELATION 3)
H
I-J
0
LJJ
I-
8
C—)
0
x
w
=
>-
-J
U-
=
-------
in Figure VII-3. 3 ’ 2 (It should be noted that the two curves
in this figure are merely reciprocals of each other.) Based
on the availability of toxicological data, 96 hours has been
defined as the upper limit of interest for acute spills.
Therefore, it is necessary only to select a lower limit. From
Figure VII-3 it is apparent that 95 percent of all fish kills
have a duration of six hours or more. By implication then, most
contaminant plugs resulting from spills require at least six
hours to pass a point. This does not imply that the spills
themselves occur over a period of six hours, but that after
initial mixing, contaminant plugs typically require more than
six hours to pass a stationary point. Consequently, the time
of passage range of interest is 6-96 hours.
With the range of interest (6-96 hours) thus defined, it is
necessary to determine where, in that range, the point associated
with minimum harmful quantity occurs. In Appendix L, it is
shown that for most hazardous substances the minimum for the
entire relation HQ = QCT/K occurs at a time of passage less
than six hours. Thus, the smallest harmful quantity in the
range of interest (6-96 hours) will occur at the six hour point;
i.e., if the minimum harmful quantity occurs to the left of the
six hour point in Figure VII-2, no point to the right of the six
hour level will have a lower value than that at six hours.
3 ”Pollution-Caused Fish Kills in 1960,” U. S. Department of
Health, Education, and Welfare, Public Health Service, 1960.
“Pollution-Caused Fish Kills January—September 1961,” U. S.
Department of Health, Education, and Welfare, Public Health
Service, Washington, DC, November 1961.
“Pollution-Caused Fish Kills in 1963,” U. S. Department of
Health, Education, and Welfare, Public Health Service, Wash-
ington, DC, 1963.
6 ”Pollution-Caused Fish Kills in 1964,” U. S. Department of
Health, Education, and Welfare, Public Health Service, Wash-
ington, DC, 1964.
7 ”Pollution-Caused Fish Kills in 1965,” U. S. Department of
the Interior, Federal Water Pollution Control Administration,
Washington, DC, 1965.
8 ”Fish Kills by Pollution in 1966,” U. S. Department of the
Interior, Federal Water Pollution Control Administration,
Washington, DC, 1966.
9 ”pol lution-Caused Fish Kills in 1967,” U. S. Department of
the Interior, Federal Water Pollution Control Administration,
Washington, DC, 1967.
10 ”pollutionCaUsed Fish Kills in 1968,” U. S. Department of
the Interior, Federal Water Pollution Control Administration,
Washington, DC, 1968.
‘ “1969 Fish Kills Caused by Pollution,” Federal Water Quality
Administration, USGPO, Washington. DC, 1970.
12 ”Fish Kills Caused by Pollution in 1970,” U. S. Environmental
Protection Agency, USGPO, Washington, DC, 1972.
11—105
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ACCUMULATED PERCENTAGE OF REPORTED
FISH KILLS VERSUS DURATION
100
U.: I I I
Cl) I
-
z 80 ACCUMULATIVE PROBABILITY OF FISH KILLS
I I I LASTING EQUAL TO OR LESS THAN THE
H W 60 - INDICATED NUMBER OF DAYS
H Ow - I
4O I
- I ACCUMULATIVE PROBABILITY OF FISH KILLS
LASTING EQUAL TO OR GREATER THAN
20 THE INDICATED NUMBER OF DAYS
I- I
4 I I
II I
10 15 20 25
DURATION OF FISH KILLS IN DAYS
FIGURE VII-3. ACCUMULATED PERCENTAGE OF REPORTED FISH KILLS VERSUS DURATION 312
-------
As shown in Appendix L, the latter condition does indeed prevail
for most hazardous substances. The controlling variable in
determining the location of the minimum point for the overall
relation is the value of the incipient time threshold, the
asymptote approached by time—dose mortality curves as the
minimum time required to kill fish when toxic materials are
present at high concentrations. As long as this threshold is
less than six hours, the time associated with a minimum harmful
quantity will be less than six hours. In general, the incipient
time threshold has been found to be less than one hour for all
hazardous substances for which time-dose mortality information
has been reviewed. Consequently, no materials have been identified
for which the absolute minimum harmful quantity would occur at
a time (T) greater than six hours and, hence, usage of a six hour
time of passage will represent the smallest harmful quantity in
this time range of interest. While smaller harmful quantities
would result from use of times less than 6 hours, these are
rejected on the basis that most spills are simply not concentrated
into such short, intense plugs.
As a result of this finding, the nature of the required application
factor can be clearly defined. It must be an appropriately
selected quantity to 1) reduce the time of passage from 96 hours
to six hours, and 2) convert the 96 hour LC 50 to a critical con-
centration representative of six hour exposures. The first
task is simple in that one needs only to divide by 16 (96 hr/6 hr).
The second is more difficult.
Ideally, one would avoid use of any application factor and
merely operate the model employing a six hour time of passage
and the six hour LC 50 for each hazardous substance. Unfortunately,
six hour LC 50 information is nonexistent for most materials.
Thus, an application factor is necessitated which represents a
quantification of the average relation between the 96 and 6 hour
LC5O’s. This can be accomplished only through further analysis
of time—dose mortality re].ations such as those illustrated in
Figure VII—4.
Available time-dose mortality relations were gathered and reviewed
to determine the average relation of the 96 hour LC 50 to the six
hour LC 50 . (This data is rather sparse and is not routinely
gathered in the United States. Hence, Canadian and European
sources provided the bulk of the data analyzed.) The ratios
of the 96 hour to the six hour LC 59 for designated hazardous
substances and common aquatic species are presented in Table VII-l.
It is evident that no single value characterizes a chemical or
species. Values fall anywhere in the range 0.006-1.0 as a function
of both the species and the chemical. In the absense of a strong
rationale for selecting any single value, it is recommended that
the mean value, 0.5, be employed as representative. It can be
11—107
-------
REPRESENTATIVE TIME-MORTALITY CURVES
FIGURE VII-4.
REPRESENTATIVE TIME-DOSE
MORTALITY CURVES’ 4+, 3 5
13 Calamori, D. and R. Marchetti. “The Toxicity of Mixtures
and Surfactants to Rainbow Trout ( Salmo gairdneri Rich.),”
Water Research , Vol. 7, 1973.
‘ “Herbert, D. W . M. and J. C. Merkins. “The Toxicity of
Potassium Cyanide to Trout,” J. Exp. Biol. , Vol. 29,
pp. 632—649, 1952.
35 Lloyd, R. and D. H. M. Jordan. “Some Factors Affecting
the Resistance of Rainbow Trout ( Salmo gairdneri ) to Acid
Waters,” J. Air & Water Pollution , Vol. 8, pp. 292—403, 1964.
(1)
0
100
U i
I-
-I
4
>
>
(I )
2
4
0
U i
I
96
CONCENTRAT 1ON (MG/L)
Z = RATIO OF TLm 96 x 16/TIm 6
11—108
-------
TABLE Vu-i
THE RATIO OF 96 TO 6 HOUR LC5O FOR COMMON SPECIES
EXPOSED TO DESIGNATED HAZARDOUS SUBSTANCES
96 Hr LC fl
— Species Substance Ratio = 6 Hr LCç Reference
Rainbow Trout NH 4 CL 1.00 2, 23, 27, 29
Fluoride 1.00 17
NH 3 0.96 2, 27, 32
ABS 0.85 13
Phenol 0.74 22, 28
CN 0.60 14, 31
Cl 2 0.39 34
ZnSO 4 0.38 2, 27, 9
Zn 0.28 2, 27, 9
Cu 0.25 13
DDT 0.01 15
Hg 0.006 13
Salmon Phosphorus 0.29 19
Cu 0.21 24, 25
0.13 2
Cu 0.06 2
Cu 0.06 24, 25
DDT 0.01 20
Phosphorus 0.006 19
Cod ABS 0.57 18
Phosphorus 0.11 19
Phosphorus 0.006 19
Bluegill Benzene 1 33
Anilizie 0.06 33
Common perch NH 3 0.34 30
Phenol 0.19 30
Cn 0.05 30
Crab Zn 0.12 21
Hg 0.02 21
Cu 0.006 21
Shrimp Cu 0.08 21
Hg 0.006 21.
Harlequin Fiah KCN 0.83 16
Na 2 S 0.59 16
Phenol 0.34 16
DDT 0.02 15
11—109
-------
noted that this value is also the median value of those reported
for rainbow trout. Insufficient data on remaininq soecies
prohibits a further analysis for median values. There .1-s also
some basis in theory for selecting the mean or median value.
Wuhrmann 30 notes that both the incipient lethal concentration
(the asymptote with essentially infinite exposure) and the slope
of the time-dose mortality relation are measures of the relative
sensitivity of a species. Since it has previously been determined
that toxicity data should be that for a median receptor, it is
reasonable to assume that a median value for the 96 hour to 6 hour
LC 5 O ratio representative of a median average slope on the time-
dose mortality curve is the best selection.
Combining the quantities required to modify the plug flow equation
for deriving a harmful quantity, one obtains an application factor
(S) with a value of
1) conversion of T from 96 to 6 - factor 1/16
2) conversion of C 96 toC 6 - factor 2
S = (1/16) x (2) 0.125
Therefore, an application factor of 0.125 is required to trans-
form the plug flow model (using 96 hr LC 0 values) into a useful
formulation for deriving harmful quantities for acute hazardous
material spills. The DORM model now requires only a representative
flow rate to make it operative.
Stream Quantity Determination
Using equation VII-2 for any given stream with a known flow
rate (Q), it is possible to compute the quantity of hazardous
material (HQ) which would be required to form a plug of duration
(T) and concentration (C). Both C and T have been defined. Thus,
in order to obtain a harmful quantity, one need only define the
stream size, represented by its flow rate (Q).
Ideally, a harmful quantity could be assigned to each and every
stream and river reach in the United States on the basis of its
average median flow rate. This would result in a rather voluminous
set of site specific harmful quantities. Aside from the tremendous
effort that would be required to determine these harmful quantities,
such a system would most certainly present an awesome administrative
burden to the regulatory agency and operators. of mobile sources
who would be required to identify receiving waters and their
flow rate in order to know the nature of the reporting requirements.
30 Wuhrmann, K. “Concerning Some Principles of the Toxicology of
Fish,” J. Fish. Res. Bd. Can. , Translation Series No. 243,
August I 59.
11—110
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Recognizing these shortcomings, a simplified approach was utilized
to determine the representative stream flow for the DOHM plug
flow model. This approach is detailed in Appendix J. In brief,
the continental United States is divided into twenty—four drainage
basins, for which the daily runoff from each is determined and
characterized as a percentage of the total daily runoff from the
continental United States. Each basin is then classified into
one of six categories on the bases of annual runoff (e.g., 0—5
inches of runoff, 5-10, 10-20) and each category is assigned
a value equivalent to the total percent of United States flow
which originates in the basins of each category. These values
are subsequently used as weighting factors in the final deter-
mination of the representative flow for the DOHM model.
Representative basins for each of the six categories were then
selected for detailed analysis focused on determining the fraction
of the total volume of water flowing in the basin (at the median
flow rate) at various discharge rates (Q) . The manner in which
the median was calculated is presented in Appendix J. By
ranking the discharges and their associated volumes for each
basin from high to low, it is possible to obtain an accumulative
percentage of total volume versus discharge rate.
When the above operation has been performed for the representative
river basins, a weighted average (incorporating the previously
derived weighting factors) can be utilized to obtain a representative
stream discharge rate (Q) for the entire United States. Mathe-
matically the preceding takes the following form:
Q = W 1 X 1 + W 2 X 2 + • • + WiX
where Q = representative United States discharge value
to be applied in the DOHM model
W = fractional weighting factor, based upon a drainage
basin’s average annual runoff category
X 1 = stream flow values representing a particular
accumulative volume percentage of the flow in a
river basin for each runoff category.
This analysis was performed on the selected river basins listed
in Appendix 3. The results of this analysis are presented in
Figure Vu-S which depicts the percent of total flow in the
United States which is flowing at or above a particular discharge
value on a median flow basis.
The flow rate at which 95 percent of the volume of water is
represented by streams of equal or greater discharge has been
chosen as the quantity of water for the DOHM plug flow model.
This value is equivalent to 1 m 3 /sec (36 cf s). Admittedly, the
11—111
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LO
0.9
0.8
w
0
.
a5
F
0.4
LU
C )
0.3
0.2
0.1
FIGURE VII-5. PERCENT OF TOTAL FLOW CONTAINED IN STREAMS
OF THE STATED MEDIAN FLOW PATE OR GREATER
10 100
DISCHARGE (CFS)
io,xx 100,000
1,000,000
-------
95 percent quantity selected here is somewhat arbitrary and could
be replaced with any other cumulative fraction. The important
point is not the absolute value selected so much as the realiza—
tion that 100 percent is an infeasible level. Data are presented
here to allow use of any other percentage should a strong
rationale be developed to replace 95 percent.
Lake Model
The lack of sufficient data on lakes of the United States and
their characteristics (size, shape, trophic state, overturn
rate, flushing rate) has limited the available approaches for
determining a representative lake quantity for the DOHM Method-
ology. Ideally, one would develop a statistical profile of the
percent of total lakes or total lake waters (volume basis) in
the U. S. represented by lakes of a given size or greater. If
lake volume were used, the Great Lakes and several other large
lakes such as Lake Tahoe would dominate the percentages. If
either approach were taken, a detailed listing of lakes in the
United States would be required. Such a compendium is not
presently available and what data bases exist, are often biased
to lakes with high present recreational values. For these
reasons, a statistical approach was discarded.
A second tact was, taken. It was noted that many impoundments
or lakes are integral parts of a river system. As such, there
is a continual exchange of river and lake waters. Since it is
these lakes that are often threatened by spills, it is not
unreasonable to employ them as representative of impounded
waters. Following this line of reasoning, lake and river waters
were classified jointly as freshwaters and given identical
harmful quantities. Since the application factor converts the
plug flow model to a 6 hour basis, this constitutes use of
36 cfs x 6 hrs x 3600 sec/hr x .0283 ft 3 /m 3 =
(Q) (TxS) (K) (K)
21,600 m 3 (17.5 acre—feet)
as the critical volume for lake waters. This implies that
statistically important lakes are those which contain 21,600 m 3
of water or more.
Estuarine Model
Section 311 specifies that a harmful quantity must be established
for each hazardous material for all navigable waterways of the
United States. Estuaries are some of the most heavily used
transportation arteries in the world and consequently are very
susceptible to spills of hazardous materials. Generalization of
a plug flow model to an estuary is much more difficult than to
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a river or stream. The estuary has several different dimensions
to consider in comparison to a stream or river. Tides cause
oscillatory motion of the water within the estuary, and the
strength of the tide dictates the turbulence (or lack thereof)
which will occur. The salinity difference between the ocean
waters and the fresh waters results in stratification and
internal (and opposing) currents developed between the fresh
and salt water layers. Many estuaries, due to their size, are
influenced by the earth’s rotation and salinity variations
within the estuary can arise due to the Coriolis force. Further-
more, estuaries are influenced by the volume of freshwater inflow
occurring at any given time as well as by periodic changes in
physical characteristics. All these factors influence the
flushing and diluting action of the estuary and therefore
assist or hinder the dispersion of a contaminant in the waterway.
Several definitions of estuaries exist. The working definition
which will be utilized as a guide in the development of this
methodology is: “a semi-enclosed coastal body of water which
has a free connection with the open sea and within which sea
water is measurably diluted with fresh water derived from land
drainage. 36 Furthermore, the estuary is defined as being
bounded at the head by the most upstream point of measurable
quantities of ocean-derived salt and at the mouth b the farthest
continuous point of land extending into the ocean. 3 Due to an
estuary’s dynamic condition, the head end is not stationary.
Depending upon the strength of the tide and the corresponding
river flow, the estuary’s head location may significantly vary.
Estuaries can be subdivided into several general classifications.
The most prevalent classes include the statified, the partially
mixed, arid the fully mixed estuary. Each type has distinct
density, stratification, and circulation pattern characteristics.
Furthermore, due to changing hydrologic and physical characteristics,
few estuaries can be continuously classified as being only one
of the preceding types. The classification an estuary assumes
depends primarily upon the tributary inflows, tidal flow, width,
and depth. 37 Considering all other parameters equal, an estuary
tends to shift from a highly stratified to a partially mixed, and
then to a vertically homogeneous estuary with
1) Decreasing river flow,
2) Decreasing tidal velocities,
36 Pritchard, D. W. “Dispersion and Flushing of Pollutants in
Estuaries,” ASCE, Hydraulics Division , pp. 115-124, January
1969.
37 pritchard, D. W. “Estuarine Circulation Patterns,” ASCE,
Hydraulics Division , pp. 717—1 - 717-11, June 1955.
11—114
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3) Decreasing width, and
4) Decreasing depth. 38
Many estuaries, as typified by the estua:ies of the Pacific
Northwest, fluctuate through the complete cycle of estuary
classifications during the course of a calendar year.
Numerous investigators have observed a correlation between an
estuary’s condition (stratified, partially mixed, or fully
mixed) and the ratio of the fresh water discharged during a
half-tidal cycle ( l2.4 hours) to the tidal prism (volume of
water represented by the difference between the estuary’s size
at mean high and mean low water). 3839 Naturally, such fluctu-
ations influence the dispersion of a contaminant within an
estuary.
For a fuller appreciation of the complexity of estuarine systems
versus river systems, the reader is referred to Appendix K
where the three prominent classes of estuaries are discussed
in more detail.
Of the three predominant estuarine classifications, investigators
have found that the artia1ly mixed estuarine system is by far
the most prevalent.’” This type of estuary can be conceptualized
as a two flow system. The fresh water has a net seaward advance
along the surface of the estuary and the salt water has a net
landward movement along the bottom. Turbulence at the interface
results in a local condition of partial mixing. In the case of
a hazardous material spill into a partially mixed estuary,
dilution water would be provided by 1) the fresh water tributary
inf low, anc 2) the ocean water flowing upstream during a flood
tide. Hence, the contaminated area can be visualized as being
flushed and dispersed by two streams of flow. This generality
applies quite well for the completely mixed estuary and has
increasingly less applicability as the estuary approaches the
stratified state.
Several authors have indicated that a partially mixed estuary
has a ratio of fresh water inflow (Qt) to tidal prism (P) on
the order of 0.1 — 0.5 (0.1 < Qt/P < 0.5) •3839
38 Burt, W. V. and W. B. McAlister. “Recent Studies in the
Hydrography of Oregon Estuaries, Research Briefs, Fish
Commission of Oregon,” Vol. 7, No. 1, pp. 14-27, July 1959.
39 simmons, H. B. “Field Experience in Estuaries,” Estuary
and Coastline Hydrodynamics , McGraw-Hill Book Company, Inc.,
pp. 673—690, 1966.
0 pritchard, D. W. “Observations of Circulation in Coastal Plan
Estuaries,” Estuaries , American Association for the Advancement
of Science, pp. 37—51, 1967.
11—115
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Choosing a ratio of Qt/P = 0.1 for the model development will
result in the inclusion of the majority of partially mixed and
fully mixed estuaries. A flow ratio greater than 0.1 would
result in improved dispersion of the contaminant. Hence, the
use of 0.1 constitutes a conservative assumption. For the
statified estuaries (Qt/P 1.0) the dilution water available
in comparison to a partially mixed estuary can be an order of
magnitude larger, or can be essentially zero depending upon
where the spilled material resides. Lighter materials (SpG < 1)
will sink to the salt wedge where dilution is minimal and hence
may lead to high concentrations over an extended time period.
Water Quantity Determination
To facilitate the estuarine analysis, the model estuary is defined
as an elongated indenture in the coastline with a single river
source of fresh water at the upper end and a free connection with
sea at the lower end. A partially mixed system with a Qt/P = 0.1
conceptualized as a system with two opposing streams of diluting
water was utilized.
The model to be presented in the following pages represents a
modification of Fischer’s proposed model dealing with the
continuous discharge of pollutants into an estuary.”’ In
addition to those already presented, the following assumptions
have been made:
• Complete mixing of the hazardous material in the
combined two stream flows (fresh tributary water
and new ocean water), and
• Instantaneous mixing of the contaminant to a
uniform concentration equivalent to the mean
toxicity level.
The degree of mixing of the hazardous material will depend upon
the extent of partial mixing of the estuary existing at the time
of discharge. Instantaneous mixing of the contaminant to a uniform
concentration wi.1l result in the formation of a plug. Again,
the validity of this assumption is dependent upon the state of
mixing existing within the estuary and actually may vary diurnally
within any one estuary. This conceptualization leads to the
illustration in Figure VII-6.
The streams (tributary and ocean flow) will result in the following
concentration of spilled material (assuming the spill volume is
negligible in comparison to th two stream flows):
“‘Fisher, H. B. “Affidavit Concerning Section 307,” for the
U. S. Environmental Protection Agency.
11—116
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C = M/ [ (Qt + RP/D) x (T)1 (VII—3) 1
where R = tidal exchange ratio——the ratio of new ocean
water to total tidal flow rtDving past the
location of the spill during a flood tide,
P = tidal prism upstream from the spill discharge
point, (cubic feet)
D = duration of tidal cycle (24 hours and 50
minutes in seconds),
Qt = tributary discharge, (cubic feet per second)
C = concentration of material on the combined
streams flow (lbs/ft 3 ), set equivalent to
critical concentration for the purposes of
harmful quantity determination,
M = quantity of material spilled, (ibs)
T = time of the total plug formed to pass a
point (leading edge to trailing edge),
(seconds) and
RP/D = effective flow of new ocean water passing
the discharge point (water not contained
in previous tidal cycle) (cfs).
Since the estuarine system has been idealized as a stream with
an effective discharge (Q), characterized by the summation of
total inf lows and outflow, the plug flow model can be extended
EFFECTIVE FLOW OF
NEW OCEAN WATER (RP!D)
MIXED FLOW TOWARD OCEAN SPILL TR I BUTARY (Qt )
LOCATION ION INFLOW
FIGURE VII-6. TWO DILUTION STREAM SYSTEM 7
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to this situation. As in the case of the stream, the hazardous
material spilled will be idealized to spread out into a 96 hour
plug of uniform concentration equivalent to the mean toxicity
level for a median receptor. Naturally, such an idealized plug
Size may never occur in an estuary. Hence, the application factor
discussed previously in the stream model section will be applied
to the preceding formula to adjust the harmful quantity in order
to reflect the possibility of higher concentration levels in a
shorter length plug. Thus, equation (VII-3) can be rearranged
to include the application factor in order to determine a harmful
quantity level
HQ (Qt + RP/D) (T) (C) (S) (K) (V1 1-4)
where K unit conversion constant
S = application factor
HQ = harmful quantity.
The preceding formula can be simplified by applying the law of
conservation of mass to the salinity balance of the estuary obtaining
HQ = K ( S Se Qt) (T) (C) (S) (VII—5)
A more detailed derivation of the above relation is given in
Appendix K. Hence, to apply the preceding formula to an estuary
one needs to know
So = average salinity of the ocean waters,
Se = average salinity of the water leaving the estuary,
Qt = tributary discharge, and
S = application factor
In the generalized case, the average salinity of the ocean waters
can be assumed to be 34 ppt and the average salinity of the water
leaving the estuary would be 31 ppt since Qt/P has been assumed
to be equal to 0.1. The tributary inflow value was obtained in
a fashion similar to the approach used to derive the discharge
rate (Q) in the stream model. Data from the National Estuarine
Pollution Study 1 ’ 2 was analyzed to obtain a cumulative percentage
of estuarine inflow versus the inflow rate (Qt). The results
of this analysis are presented in Figure VII-7. As with the
1’2 ”National Estuarine Pollution Study,” a report to the 91st
Congress by the Secretary of the Interior pursuant to Public
Law 89—753, March 1970.
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100
90
80
70
o50
‘ -I 4Q
I-.
LU
20
10
0
20,000
MEAN FLOW (CFS)
FIGURE vii-7. FRACTION OF TOTAL ESTUARINE INFLOWS (Qt) DERIVED FROM
STREAMS WITH THE STATED MEDIAN FLOW OR GREATER
1000 2000 5000 10,000 15,000
-------
stream model, the 95th percentile was selected as the threshold.
The average flow corresponding to this 95 percent level was
11.33 cubic meters/second (400 cfs) which is approximately
correlated with a median flow of 5.67 cubic meters/second (200 Cf s).
This median flow rate is used in equation VII—5 to compute harm-
ful quantities for estuaries.
Ocean Model
Since the outer limit of the estuary has been defined as the
furthest continuous point of land extending into the ocean,
spills just outside the mouth of an estuary would be defined
as occurrincr in the coastal zone. In such a situation, subject
to localized hydrodynamics, the threat of significant harm
occurring to the biota of the estuary could be substantial.
Furthermore in many instances, operators of mobile sources
would find it most difficult to determine if a coastal spill
occurred within estuarine or coastal waters. Therefore for
the DORM approach, harmful quantities derived for a model
estuary have been applied to the contiguous zone as well.
Consequently, a single harmful quantity is designated for all
marine waters just as a single harmful quantity is designated
for all fresh waters. This is equivalent to employing a volume
of ocean water of
6 hrs x 200 cfs x 10 x 3600 sec/hr x .0283 m 3 /ft 3 = 1,370,000 m 3
(TxS) (Qtxso e) (K) (K)
(1120 acre—feet)
Harmful Quantity Calculation
With the parameters in equations VII-2 and Vu-S specified, the
harmful quantity for each water body can be determined. The
appropriate equations for each of the water bodies are shown
in Table VII-2.
The stream harmful quantity equation is based upon the flow rate
at which 95 percent of the volume of water is represented by
streams of equal or greater discharge. A harmful quantity has
been calculated for each substance within each water body and
the values have been tabulated in Appendix N. Example harmful
quantity calculations are presented in Table VII-3.
Locational Factor
Greater resolution could be obtained if the plug flow model were
modified to employ the actual flow of the receiving water as well
as real hydrodynamic characteristics. This would be applicable
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TABLE VII-2
HARMFUL QUANTITY EQUATIONS
Applicable Harmful
Water Body Quantity Equation ( Kilograms) ( Pounds )
Stream (Eq VII-2) HQ = 43.9 CC 96.8 LC 50
Estuary (Eq ViI-5) HQ = 2773 CC 6113 LC 50
Lake (Eq VII-2) HO = 43.9 CC 96.8 LC 50
Ocean (Eq VII-5) HQ 2773 CC 6113 LC 50
CC = critical concentration
TABLE VII-3
EXAMPLE HARMFUL QUANTITY CALCULATIONS
Freshwater
Critical Saltwater
Concentration Critical Concentrations
Chemical ( mg/i) ( mg/i )
Acetaldehyde 53.0 70.0
Phenol 12.0 23.5
Cadmium sulfate 5.6 15.1
I) Stream and lake
i) Acetaldehyde: HQ (43.9) x (53) = 2327 kg (5126 ibs)
ii) Phenol: HQ = (43.9) x (12) = 527 kg (1161 1bs’
iii) Cadmium sulfate: HQ (5.6) = 255 kg (542 ibs)
II) Estuary and ocean
1) Acetaldehyde: I-LQ = (2773) x (70) = 194,000 kg (428,000 ibs)
ii) Phenol: 110 = (2773) x (23.5) = 65,200 kq (144,000 ibs)
iii) Cadmium sulfate: HO = (2773) x (15.1) = 41,800 kg
(92,000 ibs)
only to stationary sources where the receiving waters likely to
accept a discharge could be evaluated prior to an actual spill.
Such a variation would tailor harmful quantities to individual
geographical locations. The approach would not apply to mobile
sources, since reporting requirements would necessitate the
operator to estimate the flow or any receiving waters into which
a spill might have occurred. The obvious risk of criminal
penalty would influence toward conservative estimates. This
could be avoided by setting a single standard guideline for
mobile sources. This modification has not been made in the
trial calculations presented here.
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A second modification which can be made is the designation of
a separate harmful quantity for spills from barges based on the
realization that barge traffic is unique to streams with larger
flow rates. An accumulative flow determination has been made
for rivers and streams carrying barge traffic in the same manner
as described previously for the stream and estuary models.
Assuming a 95 percent threshold as before, a flow rate of 172
m 3 /sec (6190 cfs) should be employed in the harmful quantity formu-
lation. This would result in harmful quantities for barge spills
approximately 172 times as large as those for spills into streams
in general. This modification has not been employed for the cal-
culations presented here.
RATE OF PENALTY
Cost of Prevention
Two general concepts are expressed within Section 311 concerning
the spillage of hazardous materials. Subsection (b) (1) states
that “. . .no discharge of oil or hazardous material shall be
permitted in navigable waters of the United States...”. Further-
more, the law recognizes that spills or discharges do occur and
in subsection (b)(2) (B) (iii) states that “...discharge(s) (of)
any hazardous substance determined not removable. . . shall be
liable.. .for either one or the other of the following penalties...”.
The apparent goal of Section 311 as it applies to non-removable
hazardous substances is the elimination of their discharge
through the use of monetary penalties which act as an inducement
to the spiller to initiate positive actions to prevent spillage.
In order for these penalties to be effective deterrents, the
potential penalties assessed an individual or corporation must
be sufficiently high to provide economic incentive to reduce or
eliminate spillage. For the economically rational firm, the
incentive to prevent spillage will occur when the annual level
of assessed fines exceeds the annual cost of prevention equipment
(assuming externalities such as public relations and image have
a minor influence upon the decision). Hence, the individuals or
organizations influenced by Section 311 will have to review their
spill history records to assess the risk of penalties that they
may incur and weigh this additional cost of operation versus the
cost of installing various prevention techniques in order to
reduce or eliminate their spills. If the fine levels fall below
the cost of preventing the occurrence of the spill, it is probable
that the organizations affected will elect to run the risk of
paying a penalty and the influence of the fine schedule will be
negligible. On the other extreme, if the fine levels are
exorbitantly high, the companies will in all likelihood be
either forced out of business or into the courts. However, if
the fines equal or just exceed the cost of preventing the spill,
positive action on the part of the affected organizations can be
expected and the number and quantity of spills will most likely
be reduced. In such a case, the implemented methodology would
11—122
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be successful in approaching the expressed goal of the law. •no
spills of hazardous materials.
The intent of this methodology is to equate the penalty assessed
a spiller to the cost of preventing the spill. In order to
derive the cost of prevention, trade organizations (Manufacturing
Chemists Association, Association of American Railroads, Truck
Trailer Manufacturing Association, National Tank Truck Carriers,
Inc., Department of Transportation) as well as individual indus-
trial firms, were contacted to provide information concerning
the best means of preventing spills, the cost of such prevention
techniques, the efficiency of the techniques in preventing spills,
and the secondary costs which may occur due to the implementation
of the prevention techniques (the individual industrial firms
have requested to remain anonymous). The data supplied by the
preceding organizations and their member firms were compiled to
develop a cost of prevention for stationary sources and two
transportation sources (rail and barge).
During the course of the methodology development, it became
apparent that the cost of prevention was unrelated to the
toxicity, dispersion, or degradation characteristics of the
substance. However, the cost was a function of the substance’s
corrosiveness or flammability. Consequently, prevention costs
have been developed along these lines.
For each source classification (e.g., transportation) and sub—
classification (e.g., rail and barge) numerous prevention tech-
niques or methods exist or have been proposed. In order to
reduce the complexity of developing a cost of prevention for
a source of discharge, it became apparent that a single pre-
vention technique would have to be selected upon which a single
cost could be developed. The selection was based upon the
prevention technique which has received the greatest use or
recognition as being effective by those organizations which
responded to the authors’ initial request for information. The
resulting cost of prevention presented here is based upon the
single prevention technique, or combination of techniques,
described.
The cost of prevention has been defined for the purpose of the
study as the total annualized capital and operating costs involved
in equipment, structures, engineering fees, and manpower which
are solely directed to the prevention of a discharge of hazardous
material. The efficiency of the prevention techniques is
expressed as the percent of the total production which is
prevented from being spilled by the instigated techniques or,
in o kier words, the quantity of material prevented from being
spilled. Hence, the return on investment realized by an organi-
zation for its efforts is equivalent to the ratio (dollars!
quantity) of the preceding two figures. For this methodology,
11—123
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the rate of penalty is equal to the dollars spent on spi.Li pre—
vention equipment per unit quantity prevented from being spilled.
All of the cost of prevention figures are based upon data
provided by only a small percentage of the organizations producing
or transporting hazardous materials. Because of the small sample
that responded to the request for data, the cost figures may
require adjustment at a later date when more complete information
becomes available. The development of the cost of prevention
figures is discussed for each classification below.
Stationary Sources
The cost of prevention for stationary sources has been based upon
spill containment equipment and structures. These facilities
include dikes, levees, drainage ditches, sewers, sumps and
pumps, weirs, holding tanks or ponds, monitoring equipment, roofs
over process areas (to reduce the collection of rainwater),
valves, concrete pads, and other similar devices. A detailed
discussion of prevention measures arid equipment can be found
in Goodier, et a1. 3 The data collected reflect the cost of
installing equipment similar to the preceding, and the effect-
iveness of such installations.
Two major manufacturers of chemicals and their byproducts
responded to the authors’ inquiries. The data received indicated
a mixture of containment schemes but similar overall prevention
costs.
Data received from one of the companies indicated a cost differ-
ential between corrosive or flammable substances and others.
The cost differential reflects the added costs of utilizing
more resistent construction materials and extra precautions for
the former substances. This company indicated that over a two
and one half year period, the reduction of spillage of materials
ayeraged 24.26 in per year (6400 gallons per year). Since the
figure represented a mixture of materials, an average specific
gravity of 1.0 has been assumed. Hence, the quantity of
material prevented from being spilled is equivalent to 24,260 kg
(53,480 ibs) per year.
The cost of prevention for noncorrosive, nonflammable sub-
stances, as reported by this company, was $1 x i0 6 , which
annualized over a 15 year life (as reported by industry) at 12
percent amounts to $147,000. Hence, the cost of prevention is
equivalent to
Cost of Prevention = = $6.07/kg ($2 .75/ib)
k 3 Goodier, I. L., J. I. Stevens, S. V. Marqolin, w. V. Keany
and J. R. McMalian. “Spill Prevention Techniques for
Hazardous Polluting Substances,” EPA, OHM 7102 001,
February 1971.
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The 12 percent annual interest rate is based upon the assumption
that management would elect to place their firm’s money into
profit-making ventures if the modifications were not undertaken
and that current and forecasted interest rates justify a rate of
this level.
The cost of prevention for corrosive or flammable substances, as
reported by this company, is $2.x 10 b , which annualized over a
15 year life at 12 percent amounts to $294,000. Hence, the cost
of prevention is
Cost of Prevention = 9 ° r = $12.14/kg ($5.50/it)
Hence, the average cost for both types of substances is $9.11/kg
($4. 13/ib)
Data received from the other respondent indicated that the cost
for the installation of a complete plant spill prevention system
was $3 x 106. This system of drainage lines, sumps, pumps,
weirs, valves, and holding ponds prevented the spillage of
379 m 3 (100,000 gallons) of material over a seven year period.
The average specific gravity of the material produced at tl:e
plant is 0.997. Hence, the total quantity of material contained
is equivalent to 376,935 kg (831,000 ibs). This figure converts
to an annual rate of 53,880 kg/year (118,785 lbs/year).
The estimated life of the equipment and drainage system is 25
years (as reported by the company). Therefore, at a 12 percent
interest rate, the capital recovery factor equals 0.127 and the
annualized capital cost of $381,000. The operating and main-
tenance cost averaged (during this seven year period) one percent
of the initial capital investment (or $30,000) and the annual
sampling and analyses costs were $50,000. Therefore, the total
annual expenditures are $461,000. Hence, the cost of prevention
for this complete containment is
$461,000 — 8 5 k 3 88 ib)
g
Since the above plant processes both corrosive and noncorrosive
materials, this cost of prevention already represents an average
between the two classes of substances.
The average overall stationary source cost of prevention (based
upon these two inputs) is $8.82/kg ($4.00/lb).
Non-Stationary Sources
Barge . The cost of prevention for barge transportation has
been based upon vessel design modifications. Specifically, the
individual unit cost of prevention for a barge was based upon
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the cost of utilizing double-hulled Type III barges in place
of single—hulled Type III barges. The barge size classification
was 59 m x 10.7 (195’ x 35’) with a capacity of 1134 metric tons
(1250 tons)
Type III barges are designed to carry products of sufficient
hazard to require a moderate degree of control (e.g., acetic
acid, hydrochloric acid, sulfuric acid). Each barqe must meet
certain specific standards of watertight subdivision, structural
hull strength, and tank arrangement to protect the cargo against
uncontrolled loss as a result of grounding, collision, or sinking.
Single-skin barges, in general, consist of a formed shell.
These barges have bow and stern compartments separated from the
midship by transverse collision bulkheads. The entire midship
shell of the vessel constitutes the cargo tank. Internal
hydrodynamic considerations require the tank to be divided by
bulkheads.
Double-skin barges have an inner and outer shell. The inner
shell forms cargo tanks free of appendages which facilitates
cleaning and lining. There is a void between tank (inner shell)
and barge hull (outer shell).
The single—skin Type III barqe cost was estimated (by industry)
at $176,000 and the double-skin Type III at $200,000. The equip-
ment has a depreciated life of 14 years and an annual maintenance
cost of 4.5 percent, as reported by industry. The capital recovery
factor for a 14 year life at 12 percent annual interest is 0.152.
A loss of cargo of 0.0144 percent during a four and one half year
period was reported by one of the responding industries presently
using double-hulled barges. This company estimated that had
single-skin barges been in use, their losses would have been
0.05 percent. Thus, a 0.0356 percent reduction in cargo loss
due to spill can be projected for the conversion from single-
to double—hulled vessels. Since the capacity of the model barge
was 1.13 x 106 kg (2.5 x 106 lbs), the quantity of material pre-
vented from being spilled would be 1.13 x 106 kg x 0.000356,
which is equivalent to 402 kg (887 ibs). The cost of prevention
per barge would be
Capital Cost = $200,00 — $176,00 = $24,000
Annualized Capital Cost @12% = $24,000 x 0.152 = $ 3 1 6 4 8/year
Operating and Maintenance Cost
Increase = $24,000 x 0.045 = $1,080/year
Annual Total Cost of Prevention = $4,728/year
11—126
-------
Therefore, the cost of prevention for the barge industry would be
Cost of Prevention = { 2 r = $11.76/kg ($5.35/ib)
Railroads . The cost of prevention for the railroad industry
can be based upon tank car modifications. This would include the
cost of tank car modifications and the secondary costs involved
in switchinq from one type of tank car to another (for instance,
tariff cost differentials or equipment obsolescence losses).
Equipment modifications are effective in reducing derailments or
spills caused by mechanical failures and minimizing losses in the
case of derailments resulting from other causes. Inherent in the
development of this methodology is the assumption that such
modifications will be 100 percent effective in reducing these
types of failures. If all modifications were incorporated and
equipment maintained, the realization of 100 percent reduction
in spills due to this cause would be approached (but, of course,
never reached)
Data received from shippers of hazardous materials indicated that
over a tank car’s lifetime (20—25 years), each car has a 50
percent chance of being involved in a derailment. Of all
these derailments, 17 percent result in a spill of material.
Hence, during the lifetime of a tank car, an 8.5 percent (.l7x.50)
chance of spilling any of its contents exists.
For an average parathion tank car of 45.5 m 3 (12,000 gallons)
capacity, the reduction in the amount spilled over the lifetime
of the equipment would be 8.5 percent of 45.5 m 3 or 3.87 m 3
(1020 gallons). The cost of modifying the parathion tank car
would be $1835 over the life of the equipment and would include
$353 for head shields and $1500 for installation of type F
couplers. The F coupler has the potential, when mated with
another F coupler, to protect the car against head punctures.*
Therefore, the cost of prevention is $1835/4523 = $0.41/kg
($0.18/ib) for parathion. For a substance such as phenol,
the 87.2 rn’ cars (23,000 gallons) should be converted from
internally coiled to externally coiled in addition to the other
modifications. This would add $8250 to the costs for a total
of $8250 + $1853 or $10,085. In this case, the cost of pre-
vention would be $lO,085/(87 m 3 x 8.5 percent) = $i.27/kq
($0.57/ib) . Averaging the two, the cost of prevention
for rail transportation is $0.84/kg ($0.37/ib)
*A recent study by RPI-AAR indicated the “E” couplers may be
preferable over “F” coup1ers.
Philips, E. “Final Phase 10 Report on Couplers and Truck
Securement,” Railroad Tank Car Safety Researcil and Test
Project, September 9, 1972.
11—127
-------
The preceding costs are based on the assumption that head
shields and F couplings will minimize tank car spills to a
point which is insignificant compared to present levels. This,
of course, is a generalization. The protection of appurtenances
(fill and drain spouts) would help increase the reliability of
this assumption. However, no cost estimates are available at
this time for such measures. If the cost of these modifications
is relatively small, the values calculated here should hold.
No attempt has been made to cost out modifications for hopper
or box cars. Spill data received from an AAR member firm
indicates that spills of materials transported in these cars
are insignificant when compared to spiiis from tank cars.
Further, since many of t1 ese substances are solid materials,
the likelihood of spills leading to contamination of navigable
waters is small.
Trucking . Insufficient data was available to estimate an
independent cost of prevention for spills from trucks. Of the
accidents that have been reported, 95 percent have involved
spillage at loading and unloading facilities.’ These latter
incidences would qualify as stationary source spills and,
consequently, the cost of prevention for spills from trucks has
been equated to that for stationary sources.
It has been suggested that spills from trucks themselves could
largely be prevented if valves and other appurtenances were
provided ample shielding. However, no data were found which
reports the cost or effectiveness of these measures.
Base Rate of Penalty
From the preceding data, the base rate of penalty for this
methodology is assumcd to be equivalent to the cost of prevention.
Table VII—4 summaries these penalties.
TABLE VII-4
BASE PENALTY FOR VARIOUS SOURCES
Source Base Penalty Rate
Fixed Facility
Plants $ 8.82/kg ($4.00/ib)
Transportation [ p. 11-1231
Barge $11.76/kg ($5.35/lb)
[ p. 11—1251
Rail $ 0.84/kg ($0.37/ib)
[ p. 11—127]
11—128
-------
The preceding penalty levels are based upon only a small portion
of the affected industries and, therefore, their statistical
significance cannot be asserted at this time (although some
of the data indicates significant similarities between the
individual costs of prevention for the reporting industries).
It is difficult from the data received to clearly state that
the costs are below average, about average, or average for
industry as a whole. However, it can be asserted that the cost
data provided was developed from normal prevention techniques
and that more exotic and fail-safe techniques would increase
the cost. It can be further stated that hazardous materials
with the potential to inflict significant levels of harm
(as indicated by their toxicity, solubility, and dispersal
characteristics) should be more carefully handled and controlled.
In order to incorporate such incentives in the rate of penalty,
a method to adjust the base rate of penalty according to a
substance’s characteristics has been devised.
Adjustment Factor
it is recognized that the physical characteristics of many
materials will prevent rapid dilution to threshold concentrations
or may allow for removal or destruction of much of the material
prior to the occurrence of harm and vice versa.
Section 311(b) (2) (B) (iv) clearly states that the penalty imposed
upon a spiller of a particular hazardous material should reflect
the toxicity, degradability, and dispersal characteristics of
the substance and that the penalty charged to all spillers (per
unit of measure) must vary within an order of magnitude.
In order to reflect the different characteristics of each
hazardous material, several factors have been developed to
incorporate the aforementioned characteristics.
Dispersion - Solubility Factor
The actual level of harm inflicted by a substance is a function
of the surrounding environmental conditions and the characteristics
of the material in water. The solubility of a substance reflects
its ability to dissolve into the water body and reach a toxic
concentration level. By the selection criteria utilized, sub-
stances designated hazardous have solubilities in excess of
reported toxicity levels. Since advective and diffusive forces
will be acting to disperse the hazardous material once spilled
into a water body, the ratio of the substance’s solubility to
its toxicity is a good indicator of the size of the potential
kill zone formed. The larger this ratio becomes, the greater
the quantity of water contaminated to the toxic level by the
spill and, hence, the greater the potential for harm. A high
ratio infers that the solubility of the substance is substantially
11—129
-------
larger than its mean toxicity level which indicates that a large
plug of greater than toxic concentration is likely to occur.
Naturally, the potential for damage to occur is high. On the
other hand, a low ratio of solubility to toxicity would imply
that a very small, localized plug of contaminated waters will
be formed and the potential for harm is significantly lower
than in the previous case (Figure VII-8).
In order to reflect the preceding relationship, the following
factor has been developed by the authors:
D / I
— 1 — l+log SQL
cc
D 1 = dispersion—solubility term
SOL = solubility of the substance, mg/i
CC = critical concentration of the substance, mg/i (The
toxicity is not adjusted to the 6 hour LC 50 since
this would only introduce another constant——the
application factor S-—to the formulation. D 1 is
only a measure of relative dispersibility so constants
are eliminated.)
Figure VII-9 indicates how the dispersion-solubility term
varies with an increasing or decreasing soiubility—to—mean—tox—
icity ratio. For the substances presently under investigation,
the range of D 1 is between 0 and approximately 0.87.
Toxicity Factor
A second indicator of the potential level of harm is relative
toxicity. A substance which is highly toxic to aquatic organisms
(concentration at which the substance is toxic is low) has a
greater potential to induce harm than a substance with a low
toxicity (concentration at which the substance is toxic is high).
All the methodologies utilized in this procedural formulation
have incorporated the mean toxicity level as the toxicity criteria
and it is recognized that a spill of a highly toxic substance
is likely to form a plug of substantially greater concentration
than that required for 50 percent fatality among the receptor
organisms.
In order to reflect the different potential levels of harm for
each substance, the following factor was devised by the authors:
T=’l- 1
l+iog 500
cc
11—130
-------
SATU RATED
cc
SATURATED
CC
FIGURE VII-8.
RELATIVE CHANGE IN POTENTIAL KILL ZONE
WHEN MATERIALS OF EQUAL SOLUBILITY HAVE
GREATLY DIFFERENT CRITICAL CONCENTRATIONS
w
OL)
c )
L J
-J
‘- ‘I--
zo
OL)
DISTANCE FROM CENTER OF PLUG
DISTANCE FROM CENTER OF PLUG
11—131
-------
(-3
-J
U)
—C-,
+
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
FIGURE VII-9.
SOL/cc
RESPONSE OF THE DISPERSION-SOLUBILITY ADJUST-
M.ENT TERM TO CHANGES IN THE SQL/CC RATIO
11—132
-------
T = toxicity factor
= critical concentration, mg/i (As stated earlier,
the: adjustment factors are relative. Thus there is
no need to convert toxicity to the 6 hour LC 50 value.)
500 = 500 mg/i, maximum toxicity level utilized in designating
a substance as being hazardous.
Figure Vil-lO indicates how the toxicity factor varies with changes
in the mean tcxicity of various substances. For the substances
presently designated as hazardous, the range of T varies between
0 and approximately 0.82. The factor approaches zero as the
critical concentration approaches 500. Materials with critical
concentrations >500 mg/i are given a value of T = 0. This may
occur for substances selected on the basis of oral or dermal
or other criteria than direct lethality to aquatic life.
Degradability Factor
The degradability factor reflects the environmental half—life
of the substance. A material which, upon entry into the water
body, rapidly decays due to bacterial or chenilcal action, poses
a smaller hazard to aquatic organisms than a substance which is
persistent. An assumption has been made that as material is
degraded, less is available as a contaminant and thus the
effective spill size is reduced.
D 2 = 1 - DEG
where D 2 = degradability factor, and
DEG = estimated loss in four day period.
Thus, if biochemical oxidation is the mode of degradation, DEG
equals the fractional theoretical BOD4 since the four day BOD
corresponds to the maximum plug duration of 96 hours. The
conversion from BOD5 is
BOD4 = 0.88 BOD 5
(The four-day period was selected to be consistent with the 96
hour base exposure time employed. The conversion of the plug
flow model to a six-hour time of passage through use of the
application factor, CS), is designed solely to determine harmful
quantity and does not apply here.) The characteristic of the
degradability curve is illustrated in Figure vu-li. The degrad-
ability factor varies between 0 and 1.0.
11—133
-------
0.9
U
U
0.8
0.7
0.6
0.5
0.4
0.3
02
0.1
FIGURE Vil—lO.
500/CC
RESPONSE OF THE TOXICITY ADJUSTMENT FACTOR
TO CHANGES IN THE 50 0/CC RATIO
0
0
10
101
io
11—134
-------
0.
0.9
0.8
0.7
I - .
I-I
L.)
U i
0.6
0.5
0.4
0.3
0.2
0.1
0.0
0 0.1
0.2 0.3 0.4 0.5 0.6 0.7 0.8
DEG (FRACTIONAL LOSS)
RESPONSE OF THE DEGRADABILITY ADJUSTMENT TERM TO
VARIATION IN THE FRACTIONAL LOSS CHARACTERISTIC
0.9 1.0
FIGURE Vu-il.
-------
It can be argued that each term’s ability to describe the potential
inducement of harm by a substance is not equivalent and subse-
quently each term should be considered independently. However,
data are not sufficient to indicate the importance of one term
over another. Therefore, the preceding three factors are viewed
as multiplicative.
It must be emphasized here that no attempt is being made to quantify
natural laws. The factors described above are merely operators
designed to compare relative potential harm.
With the multiplicative assumption, the total function reflecting
the substance’s dispersion, toxicity, and degradability charac-
teristics takes the following form:
xo = 1 — l+log SOL 1 - l+log 500 - DEG)
CCJ\ cc)
and the term varies between 0 and approximately 0.71.
A substance which has a high solubility to toxicity ratio and
is highly toxic but decays readily is most likely to have a
low impact upon the aquatic life of the water body. Similarly,
a low value for the other factors will drive the product value
down. Data presented in Table Vu-S have been developed to
indicate the expected impacts occurring from the various com-
binations of the preceding parameters.
TABLE VII-5
EFFECT OF THE SUBSTANCE’S CHARACTERISTICS
UPON THE ADJUSTMENT FACTOR
Solubility to Toxicity Environmental
Toxicity Ratio Level Half-life Impact
0.87 0.82 1.0 0.71
0.87 0.82 <0.5 0.36
0.87 <0.41 1.0 0.36
0.87 <0.41 <0.5 <0.18
<0.43 0.82 1.0 <0.35
<0.43 <0.41 1.0 <0.18
<0.43 0.82 <0.5 <0.18
<0.43 <0.41 <0.5 <0.09
11—136
-------
It must be reemphasized here, that no attempt is being made to
characterize a new set of natural laws. These relations are
merely designed as operators to reflect the tendencies for
certain physical properties to enhance or retard a material’s
ability to exert its hazard potential.
As previously indicated, Section 311(b) (2) (B) (iv) allows the
administrator the flexibility of varying the base penalty rate
over an order of magnitude depending upon a substance’s behavior
in a water body. However, the rate of penalty for the DOHM
Methodology is based upon the average cost of prevention for
those reporting industries. The data received from industry
indicates a cost differential of approximately two exists
for preventing the occurrence of spills depending upon whether
or not a substance is highly flammable or corrosive. The
additional measures required to prevent spills of highly
flammable or corrosive substances are expected to be similar
to those necessary to prevent the discharge of highly toxic
substances and hence, a variance from the base rate of penalty
by a factor of two is appropriate. In other words, while the
handler of extremely hazardous substances should be motivated
to install prevention systems in excess of the industrial
“average,” the incentive should not exceed twice the average
cost of prevention. The total adjustment factor (rk) is
therefore reduced to the following form:
rk = 1 + f [ (D 1 ) (T) D 2 ]
where rk = penalty rate adjustment factor, and
f = 1/0.71 = 1.41.
Since the term (D 1 ) (T) (D 2 ) varies between 0 and 0.71, rk will
vary between 1 and 2 and therefore penalties will range between
the cost of prevention and twice the cost of prevention. Rk
adjustment factors are tabulated for designated hazardous
substances in Appendix M.
The cost of prevention is converted to the penalty rate imposed
upon a spiller for the DOHM Methodology by multiplying the cost
of prevention by each substance’s rk value. Example calculations
are presented in Table VII—6 for spills in freshwater (rivers and
lakes). Rates of penalty and harmful quantities resulting from
utilization of the DOHM Methodology on designated hazardous sub-
stances are compared to those for the three alternative method-
ologies in Appendix N. It is apparent that if the prevention
incentive reviewed and adjusted periodically to reflect changes
in prevention costs/technology and/or monetary fluctuations.
11—137
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Chemical
Acetaldehyde
Phenol
Cadmium sulfate
Ace tald ehyd e
Phenol
Cadmium sultace
Acetaldehyde
Phenol
Cadmium sulfate
Base Penalty Rate
$ 8.82/kg ($4.00/ib)
$ 8.82/kg ($4.00/ib)
$ 8.82/kg ($4.00/ib)
$11.76/kg ($5.35/lb)
$11.76/kg ($5.35/ib)
$11.76/kg ($5.35/ib)
$ 0.84/kg ($0.37/ib)
$ 0.84/kg ($0.37/ib)
$ 0.84/kg ($0.37/ib)
Adjusted
$ 9.78/kg
$11.29/kg
$16.00/kg
$13. 02/kg
$15. 05/kg
$21.00/kg
$ .93/kg
$ 1.08/kg
$ 1.50/kg
Penalty Rate
($ 4.50/ib)
($ 5.12)
($ 7.10)
($ 5.91/ib)
($ 6.83)
($ 9.50)
($ .41/ib)
($ .47)
($ .68)
TABLE
VII-6
EXAMPLE CALCULATIONS OF FINAL
PATES
OF
PENALTY FOR
SPILLS
IN
FRESHWATER
Chemical CC* (mg/i)
Solubility
s, mg/i
Freshwater
rk
1.11
Acetaldehyde 53.0
>1,000,000
Basis
TL
m96
sunfish
Phenol
Cadmium sulfate
BOD 5 -1 -
93
1.27
lb/lb
13.5
5.6
H
‘i ’
H
TL
m96
bluegill
TL
m96
fathead
minnows
67,000 75
1.7—2
lb/lb
755,000 0
*Crjtjcal concentration
tDegradation (% theoretical)
1 . 28
1.72
Source
Plants
Barge
Rail
-------
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11—142
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