Hazard Ranking System Issue Analysis:
Alternative Methods for Ranking the Persistence
   of Hazardous Substances in Surface Water
                    MITRE

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     Hazard Ranking System Issue  Analysis:
Alternative Methods for  Ranking the Persistence
    of Hazardous  Substances in  Surface Water
                        Ming P. Wang
                       November 1987
                         MTR-86W172
                          SPONSOR:
                    U.S. Environmental Protection Agency
                         CONTRACT NO.:
                         EPA-68-01-7054
                      The MITRE Corporation
                        Civil Systems Division
                        7525 Colshire Drive
                      McLean, Virginia 22102-3481

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 Department Approval:
MITRE Project Approval:

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                              ABSTRACT
     This report addresses possible modifications to the persistence
ranking method in the current HRS to better reflect the environmental
attenuation potential of hazardous substances in surface water.   The
joint effect of several important processes, including
biodegradation, hydrolysis, photolysis, volatilization, free-radical
oxidation, and sorption, is evaluated using steady-state models for
idealized water bodies.  Two alternatives are proposed which rank the
persistence of substances according to the expected change of
substance concentration over the HRS target distance limit.
Alternative I considers all six processes mentioned above.  Its
application requires field measurements to quantify the fraction of
substance sorbed and the subsequent sedimentation loss of the sorbed
chemicals.  Alternative II considers all processes except sorption;
its application does not require field measurements.  In streams and
rivers, the majority of substances are expected to be ranked as
persistent (i.e., less than 50 percent reduction in concentration)
unless sedimentation loss of the sorbed substances is significant.
In general, substances are expected to be less persistent in lakes
and reservoirs than in streams and rivers because of the longer
reaction time in lakes and reservoirs and because lakes and
reservoirs are good sediment traps.

Suggested Keywords:  Persistence, Chemical persistence, Hazard
substance ranking, Hazard Ranking System.
                                 iii

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                           ACKNOWLEDGEMENT
     The author wishes to thank Lawrence Kushner and Stu Haus for
their guidance and William W. Duff, Gerald R. Goldgraben, Denton
Langridge, Steve McBrien, Andrew M. Platt, David C. Roberts, and
Vicki Ziegenhagen of The MITRE Corporation for their assistance in
the preparation of this report.

     Additionally, the author wishes to thank Francois M. M. Morel
and David A. Dzombak of Massachusettes Institute of Technology, and
Bob Ambrose and Dave Brown of EPA-ERL at Athens, Georgia, for
contributing helpful information.
                                 iv

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                           TABLE OF CONTENTS

                                                                 Page

LIST OF FIGURES                                                  vii

LIST OF TABLES                                                   viii

1.0  INTRODUCTION                                                  1

1.1  Background                                                    1
1.2  Issue Description                                             3
1.3  Objectives of the Study                                       5
1.4  Scope of Work                                                 6
1.5  Approach                                                      6
1.6  Review of Persistence Factors in Other Ranking Systems        8
1.7  Organization of the Report                                   12

2.0  MECHANISMS AFFECTING THE PERSISTENCE OF HAZARDOUS            15
     SUBSTANCES IN A SURFACE WATER ENVIRONMENT

2.1  Introduction                                                 15
2.2  Mode gradation, Hydrolysis, Photolysis, Free-Radical         21
     Oxidation, and Volatilization
2.3  Sorption                                                     25

     2.3.1 Organics                                               28
     2.3.2 Metals                                                 29

2.4  Effect of Sorption on Other Transformation Processes         32

3.0  MODELS OF SUBSTANCE FATE FOR IDEALIZED WATER BODIES          37

3.1  Overview                                                     37
3.2  Streams and Rivers                                           38

     3.2.1  General Model, Considering Both Settling and Decay    39
     3.2.2  Model With Decay Only                                 41
     3.2.3  Model With Settling Only (i.e., No Decay)             42
     3.2.4  Model With Settling Only, With Partition              43
            Coefficient as a Function of Suspended Solids
            Concentration

3.3  Lakes and Reservoirs                                         44
                                   v

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                     TABT.F, OF CONTENTS (Concluded)
4.0  ALTERNATIVES TO THE CURRENT HRS PERSISTENCE RANKING          49
     METHOD FOR THE SURFACE WATER PATHWAY

4.1  Overview                                                     49
4.2  Alternative I                                                50

     4.2.1  Streams and Rivers                                    51
     4.2.2  Lakes and Reservoirs                                  59

4.3  Alternative II                                               64

5.0  DISCUSSION AND CONCLUSIONS                                   71

5.1  Comparison of the Two Alternative Persistence Ranking        71
     Methods

5.2  Comparison With the Current HRS Persistence Ranking Method   73

6.0  BIBLIOGRAPHY                                                 83

APPENDIX A—REVIEW OF PERSISTENCE FACTORS IN OTHER SITE           91
            RANKING SYSTEMS

APPENDIX B--ILLUSTRATIVE HALF-LIVES OF SUBSTANCES IN             101
            STREAMS/RIVERS

APPENDIX C—ILLUSTRATIVE HALF-LIVES  OF SUBSTANCES  IN            111
            LAKES/RESERVOIRS

APPENDIX D—LOGARITHM OF N-OCTANOL-WATER COEFFICIENTS LOG Pow    121

APPENDIX E—-THE SELECTION OF METHODOLOGY IN ESTIMATING           139
            PARTITION COEFFICIENT OF METALS

APPENDIX F—TIME OF TRAVEL IN STREAMS AND RIVERS OF THE          145
            SURFACE WATER PATHWAY

APPENDIX G—METHODOLOGY FOR CALCULATING HALF-LIVES               149

APPENDIX H—GLOSSARY                                             155
                                  VI

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                           LIST OF FIGURES

Figure Number                                                     Page

     1          A SCHEMATIC DIAGRAM SHOWING THE IMPORTANT           40
                PROCESSES AFFECTING FATE OF SUBSTANCES IN A
                SURFACE WATER  BODY

     2          A SCHEMATIC DIAGRAM SHOWING THE IMPORTANT          45
                PROCESS AFFECTING FATE OF SUBSTANCES IN AN
                IDEALIZED LAKE OR RESERVOIR

     3          PERSISTENCE RANKING METHOD FOR SUBSTANCES IN       52
                STREAMS AND RIVERS—ALTERNATIVE I

     4          MEAN CONCENTRATION OF SUSPENDED SEDIMENT AT        57
                NASQAN STATIONS DURING 1976 WATER YEAR.  MAP AT
                BOTTOM IS CODED TO SHOW MEAN DATA FOR STATIONS
                REPRESENTING FLOW FROM THE ACCOUNTING UNIT

     5          PERSISTENCE RANKING METHOD FOR SUBSTANCES IN        60
                LAKES AND RESERVOIRS—ALTERNATIVE I

     6          CHURCHILL'S TRAP EFFICIENCY CURVE                   63
                                 vii

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                           LIST OF TABLES

Table Number                                                      Page

     1          SUMMARY OF PERSISTENCE FACTORS IN OTHER            10
                RANKING SYSTEMS

     2          RELATIVE IMPORTANCE OF PROCESSES AFFECTING         16
                THE FATE OF PRIORITY POLLUTANTS IN SURFACE
                WATER

     3          PERCENT OF A SUBSTANCE REMAINING AS A FUNCTION     23
                OF THE NUMBER OF HALF-LIVES ELAPSED

     4          EMPIRICAL RELATIONSHIP BETWEEN METAL PARTITION     31
                COEFFICIENT (Kg) AND SUSPENDED SOLIDS
                CONCENTRATION QSS)

     5          CALCULATIONS OF DISSOLVED AND PARTICULATE          33
                FRACTIONS OF SELECTED PRIORITY METALS IN
                STREAMS AT SPECIFIED SOLID CONCENTRATIONS

     6          COMPARISON OF PARTITION COEFFICIENT FOR            56
                SEVERAL SUBSTANCES USED TO SCORE TOXICITY/
                PERSISTENCE IN THE SURFACE WATER ROUTE OF
                PROPOSED AND FINAL NPL SITES

     7          CLASSIFICATION OF HAZARDOUS SUBSTANCES BY          67
                THEIR HALF-LIVES—STREAMS /RIVERS I

     8          CLASSIFICATION OF HAZARDOUS SUBSTANCES BY          78
                THEIR HALF-LIVES—STREAMS/RIVERS II

     9          THE DOMINANT PROCESS FOR SUBSTANCES WITH           82
                HALF-LIFE EQUAL TO OR LESS THAN 1 DAY
                                  viii

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1.0  INTRODUCTION




1.1  Background




     The Comprehensive Environmental Response, Compensation, and




Liability Act of 1980 (CERCLA) (PL 96-510) requires the President to




identify national priorities for remedial action among releases or




threatened releases of hazardous substances.  These releases are to




be identified based on criteria promulgated in the National




Contingency Plan (NCP).  On July 16, 1982, EPA promulgated the




Hazard Ranking System (HRS) as Appendix A to the NCP (40 CFR 300;




47 FR 31180).  The HRS comprises the criteria required under CERCLA




and is used by EPA to estimate the relative potential hazard posed




by releases or threatened releases of hazardous substances.




     The HRS is a means for applying uniform technical judgment




regarding the potential hazards presented by a release relative to




other releases.  The HRS is used in identifying releases as national




priorities for further investigation and possible remedial action by




assigning numerical values (according to prescribed guidelines) to




factors that characterize the potential of any given release to




cause harm.  The values are manipulated mathematically to yield a




single score that is designed to indicate the potential hazard posed




by each release relative to other releases.  This score is one of




the criteria used by EPA in determining whether the release should




be placed on the National Priorities List (NPL).

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     During the original NCP rulemaking process and the subsequent

application of the HRS to specific releases, a number of technical

issues have been raised regarding the HRS.  These issues concern the

desire for modifications to the HRS to further improve its capability to

estimate the relative potential hazard of releases.  The issues include:

     •  Review of other existing ranking systems suitable for ranking
        hazardous waste sites for the NPL.

     •  Feasibility of considering ground water flow direction and
        distance, as well as defining "aquifer of concern," in
        determining potentially affected targets.

     •  Development of a human food chain exposure evaluation
        methodology.

     •  Development of a potential for air release factor category in
        the HRS air pathway.

     •  Review of the adequacy of the target distance specified in the
        air pathway.

     •  Feasibility of considering the accumulation of hazardous
        substances in indoor environments.

     •  Feasibility of developing factors to account for environmental
        attenuation of hazardous substances in ground and surface water.

     •  Feasibility of developing a more discriminating toxicity factor.

     •  Refinement of the definition of "significance" as it relates to
        observed releases.

     •  Suitability of the current HRS default value for an unknown
        waste quantity.

     •  Feasibility of determining and using hazardous substance
        concentration data.

     •  Feasibility of evaluating waste quantity on a hazardous
        constituent basis.

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     •  Review of the adequacy of the target distance specified in
        the surface water pathway.

     •  Development of a sensitive environment evaluation
        methodology.

     •  Feasibility of revising the containment factors to increase
        discrimination among facilities.

     •  Review of the potential for future changes in laboratory
        detection limits to affect the types of sites considered for
        the NPL.

     Each technical issue is the subject of one or more separate but

related reports.  These reports, although providing background,

analysis, conclusions and recommendations regarding the technical

issue, will not directly affect the HRS.  Rather, these reports will

be used by an EPA working group that will assess and integrate the

results and prepare recommendations to EPA management regarding

future changes to the HRS.  Any changes will then be proposed in

Federal notice and comment rulemaking as formal changes to the NCP.

The following section describes the specific issue that is the

subject of this report.

1.2  Issue Description

     The issue addressed in this report is the feasibility of

developing factors to account for environmental attenuation of

hazardous substances in surface water.  Environmental attenuation is

used here to refer to the loss of substances from a medium of

concern through physical, biological and chemical processes.

Dilution may be an important physical mechanism for contaminant

attenuation, but it is not considered in this study.

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     Persistence is used in the HRS to reflect the resistance  of

hazardous substances to environmental attenuation while moving from

the release location to a target within a specified distance.   In the

current HRS, persistence is based only on the biodegradability of

substances.  Each substance is given an integer score from 0 to 3

using a look-up table on which nonpersistent substances are assigned a

value of 0, moderately persistent substances are assigned a value of 1

or 2, and highly persistent substances are assigned a value of 3.  For

substances not in the table, the persistence ranking value is assigned

as follows:

           Substance                               Assigned Value

     Easily biodegradable compounds                      0

     Straight chain hydrocarbons                         1

     Substituted and other ring compounds                2

     Metals, polycyclic compounds and
     halogenated hydrocarbons                            3

     EPA has received public comments during both the National

Contingency Plan (NCP) and National Priorities List (NPL) rulemakings

that question the number of loss processes considered in the current

HRS persistence ranking method.  These comments indicate that, while

biodegradation is an important mechanism affecting persistence of

chemicals in the aquatic environment, it is not necessarily the most

important attenuation mechanism for all hazardous substances.

Commenters, therefore, suggested that other physiochemical mechanisms

should be considered in rating persistence.

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     In response to these comments, EPA is evaluating the

feasibility of developing factors to account for environmental

attenuation of hazardous substances in ground and surface water.

This report is a part of that effort.

     The major attenuation mechanisms for any substance depend not

only on its chemical characteristics, but on the environment in which

it is found.  For example, photolysis (i.e., a reaction caused by

absorption of sunlight) has been identified as an important attenu-

ation mechanism for several photoreactive compounds in surface water

(Zepp et al., 1984), but it is not likely an attenuation mechanism

in ground water.  Similarly, the contribution of volatilization to

removal of pollutants in ground water is considerably smaller than

that in surface water (Zoeteman et al., 1980).  Because the

mechanisms affecting attenuation in ground water and surface water

may be quite different, it is appropriate that these environments be

examined separately.  This study focuses on the surface water

environment.  The attenuation of hazardous substances in the ground

water environment is addressed in a companion study by Sayala (1987).

1.3  Objectives of the Study

     The objectives of this study are:

     •  To identify the joint effect of several important processes
        on the fate of hazardous substances in surface water.

     •  To evaluate the feasibility of incorporating these processes
        in the HRS.

     •  To propose alternative persistence ranking schemes for the
        surface water pathway.

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1.4  Scope of Work




     Persistence of hazardous substances in the current  HRS  is




discussed in relation to the type of surface water environment  in




which the hazardous substance travels:  either streams and rivers or




lakes and reservoirs.  Since the targets evaluated in the HRS surface




water pathway are limited to those within a target distance limit,




persistence is also evaluated over a target distance limit,  considering




both transfer and transformation processes.




     This study evaluates the persistence of hazardous substances in




the surface water environment by considering several physiochemical




processes.  Their processes include five decay processes (biodegrad-




ation, photolysis, hydrolysis, free-radical oxidation, and




volatilization) and one equilibrium process (sorption).   The paper




also addresses the combined effect of various processes on attenuation.




1.5  Approach




     In order to consistently assess the contribution of each process




considered, quantitative information on each of the processes is




required.  Thus, the  feasibility of accounting for all these environ-




mental attenuation mechanisms in the HRS depends on the availability




of quantitative information such as rate constants (or half-lives) for



decay processes and partition coefficients for sorption.  Existing



ranking systems were  examined to determine whether an existing




mechanism could be adopted.  None of these systems, however, contained



the required data as  discussed below.

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     To obtain the necessary quantitative information, the
literature was searched for half-lives  (e.g., biodegradation half-
life, volatilization half-life) of hazardous substances in the
surface water environment and for partition coefficients of these
hazardous substances.  Data on half-lives and partition coefficients
were found to be available for many hazardous substances.  For other
hazardous substances these data may be  estimated (e.g., see
Appendix G).  Therefore, it was considered feasible to use such
quantitative information for the screening purposes of the HRS.
     Steady-state models were then used to estimate the effects of
the five decay processes and sorption on hazardous substances in
surface water.  For streams and rivers, the spatial variation of
cross-sectionally averaged substance concentration was described by
a one-dimensional (i.e., cross-sectionally integrated) mass balance
equation.  Lakes and reservoirs were described as idealized fully-
mixed tank reactors.  The solutions of  these steady state models
allow the concentration resulting from  the combined effect of all
six processes to be easily estimated.
     Based on the results of these calculations, two alternative
methods for assigning persistence ratings to substances in the HRS
are proposed.  In both methods, the persistence value assigned to a
substance depends on the expected reduction in total concentration
(i.e., dissolved and particulate) of the substance over the target
distance limit.  The higher the expected reduction, the lower the
relative ranking value assigned to the hazardous substance.
                                  7

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1.6  Review of Persistence Factors in Other Ranking Systems




     The following 11 systems were identified for review of treatment




of persistence (see Appendix A for more detail about these systems):




     •  JRB Methodology




     •  HARM




     •  HARM II




     •  CSR




     •  S.P.A.C.E. for Health




     •  ADL




     •  SAS




     •  PERCO




     •  Dames  and Moore  Methodology




     •  Action Alert  System




     •  RAPS




The  last  2 systems  (Action Alert System and RAPS)  do  not  consider




persistence explicitly.   Rather, they include  methodologies for




estimating the effect of environmental attenuation on the concen-




tration of hazardous  substances.  Nonetheless,  it  is  informative to




compare the loss processes considered in these 2 systems  with the




processes considered  in  the current  HRS.




     The review of these systems focused  on how the persistence




factors are used in the  various  systems and how persistence is




defined and evaluated.   When more  than one  migration  pathway  is




considered in  a system,  the  review focused  only on  the surface water






                                  8

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pathway.  The review findings are presented in Appendix A and are




summarized in Table 1.




     Despite the variation in the value assigned to each of the four




persistence ranks, seven systems (JRB Methodology, HARM, HARM II,




GSR, S.P.A.C.E. for Health, ADL, Dames and Moore Methodology) use the




same criteria as those in the current HRS to evaluate persistence of




hazardous substances.  That is, all seven systems define persistence




in terms of the biodegradability of the substance.  Qualitative




guidelines are used for ranking hazardous substances in each system.




     PERCO modifies the HRS persistence ranking criteria to give




higher persistence ratings than the other systems.  This modification




was made because of the recognition that even relatively biodegradable




substances may require days to disappear from the environment.




Consequently, areas located within several miles downstream of a




waste site may not benefit from potential biodegradation.




     Three systems (SAS, AAS, RAPS) require quantitative information,




such as half-life or decay/loss rate.  SAS considers a substance as




persistent if it has an environmental half-life longer than six




months.  The AAS requires that the overall loss rate of a substance




be estimated as the sum of the individual loss rates due to




hydrolysis, photolysis, free-radical oxidation and volatilization.




     RAPS also uses a decay rate in estimating the environmental




concentration of the substance.  However, there is no elaboration in




the RAPS documentation on the types of processes which have been

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                                 TABLE 1

         SUMMARY OF PERSISTENCE FACTORS IN OTHER RANKING SYSTEMS
System
JRB Methodology
HARM
HARM II
GSR
S.P.A.C.E. for
Health
ADL Methodology
Dames and Moore
Loss Process
Considered
HRS1
HRS
HRS
HRS
HRS
HRS
HRS
Criteria for
Ranking Persistence
HRS1
HRS
HRS
HRS
HRS
HRS
HRS
Look-up
Table
HRS1
NA
NA
NA
HRS
HRS
NA
  Methodology
PERCO
Biodegradation
SAS
     NA2
Action Alert
  System
RAPS
Photolysis,
volatilization,
hydrolysis, free-
radical oxidation

Not explicity
specified
Easily biodegradable
 compounds and straight
 straight chain
 hydrocarbons
 (Moderately Persistent)
Substituted and other
 ring compounds, metals
 polycyclic compounds
 and halogenated
 hydrocarbons (Highly
 Persistent)

Persistent, if half-life
 greater than 6 months
 Nonpersistentj if half-
 life equal to or less
 than 6 months

        NA
        NA
NA
                                                                  NA
NA
                           NA
                                                                  NA
                                 10

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                          TABLE 1 (Concluded)

                               Footnotes


1-Same processes or criteria considered as the current HRS; that is,
 only biodegradation is considered and substances are classified into
 four ranks according to the following criteria:

              Criteria                             Rank*

    Easily biodegradable compounds              Nonpersistent

    Straight chain hydrocarbons                 Low persistent

    Substituted and other ring compounds        Moderately persistent

    Metals, polycyclic compounds and            Highly persistent
    halogenated hydrocarbons
    *The numerical value assigned may be different in different
     systems.

     available or not applicable.
                                 11

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considered.  Since RAPS was developed specifically to address




radioactive waste sites, decay may refer only to radioactive decay.




     None of the systems reviewed provide an improved methodology




readily adaptable for use in the HRS.




1.7  Organization of the Report




     This report is divided into five sections.  Section 2 is an




overview of the several important transfer and transformation




processes which may act upon a hazardous substance in a typical




surface water environment.  It illustrates the need to consider loss




processes in addition to biodegradation.  It also describes the




functional relationship between the concentration of a substance and




the various processes identified.  These functional relationships




serve as the building blocks for models introduced in Section 3.




     Section 3 describes the models used to derive the variation of




the concentration of a substance over the target distance limit.




The models include all the important processes which have been




identified in Section 2.




     Section 4 describes two alternative persistence ranking methods




which may be used in place of the method currently used in the HRS.




Both alternatives are based on modeling results obtained in




Section 3.  However, the alternatives differ in that Alternative II




does not consider sorption and the subsequent settling loss while



Alternative I does.
                                 12

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     Section 5 compares the two proposed alternatives described in




Section 4.  It also compares the two proposed alternatives with the




persistence ranking method currently employed in the HRS.




     There are eight appendices in this report.   Appendix A




summarizes the reviews of persistence factors in other site ranking




systems.  Appendix B lists illustrative half-lives of substances in




streams and rivers.  Appendix C lists illustrative half-lives of




hazardous substances in lakes and reservoirs.  Appendix D  lists the




logarithm of N-octanol-water partition coefficients.  Appendix E




explains the rationale for selecting the method of estimating




partition coefficient of metals in natural environments.  Appendix F




evaluates the range of 3-mile travel times in streams and  rivers.




Appendix G outlines the methodology for calculating half-lives and




Appendix H is the glossary.
                                  13

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2.0  MECHANISMS AFFECTING THE PERSISTENCE OF HAZARDOUS SUBSTANCES IN
     A SURFACE WATER ENVIRONMENT

2.1  Introduction

     As a substance enters a water body, in addition to being diluted and

transported by the flow, it may also be subjected to several transfer and

transformation processes, including:  biodegradation, hydrolysis,

photolysis, volatilization, free-radical oxidation, and sorption.

Various studies have indicated that these processes are important in

affecting the aquatic fate of substances (e.g., Callahan et al., 1979;

Lyman et al., 1982; Mills et al., 1985; Delos et al., 1984; and Mabey

et al., 1982).  Of these processes, only volatilization and sorption do

not change the composition of a substance, rather they move the substance

from water to other environmental media (i.e., air and sediment).

     The relative importance of some of these processes in affecting the

aquatic fate of organic priority pollutants is summarized in Table 2.

In many instances, biodegradation has been identified as insignificant

in affecting the fate of substances.  For example, for most of the

halogenated aliphatic hydrocarbons, biodegradation is either an

insignificant process or its importance is not known.  For these

substances, volatilization is generally the prevailing fate-affecting

mechanism.  This table clearly illustrates the limitations of the

present persistence ranking method and the need for a modification of

the HRS.

     The remaining sections of this chapter present the formulations

commonly used to describe the effects of these six processes on the


                                 15

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                                                     TABLE 2

 RELATIVE  IMPORTANCE  OF PROCESSES  AFFECTING THE  FATE OF  PRIORITY POLLUTANTS  IN  SURFACE WATER
                                                                            Process
        Compound
Sorption  Volatilization Biodearadation  Photolysis-Direct	Hydrolysis
Pesticides

Acrolein
Aldrin
Chlordane
ODD
DDE
DDT
Dleldrin
Endosulfan and Endosulfan Sulfate
Endrln and Endrin Aldehyde
Heptachlor
Heptachlor Epoxlde
Hexachlorocyclohexane (o,P,6 isoraers)
 -Hexachlorocyclohexane (Lindane)
Isophorone
TCDD
Toxaphene

PCBs and Related Compounds

Polychlorinated Biphenyls
2-Chloronaphthalene

Haloeenated Aliphatic Hydrocarbons

Chloromethane (methyl chloride)
Dichloromethane (methylene chloride)
Trichloromethane (chloroform)

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                                              TABLE 2  (Continued)
        Compound
                                                                               Process
Sorptlon  Volatilization  Biodeeradation  Photolysis-Direct  Hydrolysis
Halogenated Aliphatic Hydrocarbons (Concluded)

Tetrachloromethane (carbon tetrachloride)          ?
Chloroethane (ethyl chloride)
1,1-Dichloroethane (ethylidene dichloride)
1,2-Dichloroethane (ethylene dichloride)
1,1,1-Trichloroethane (methyl chloroform)
1,1.2-Trichloroethane                              ?
1,1,2,2-Tetrachloroethane                          ?
Hexachloroethan                                    ?
Chloroethene (vinyl chloride)                      +
1,1-Dichloroethene (vinylidene chloride)           ?
1,2-trans-Dichloroethene
Trichloroethene
Tetrachloroethene (perchloroethylene)
1,2-Dichloropropane                                ?
1,3-Dichloropropene                                ?
Hexachlorobutadiene                                +
Hexachlorocyclopentadiene                          +
Bromomethane (methyl bromide)
Bromodichloromethane                               ?
Dibromochloromethane                               ?
Tribromomethane (bromoform)                        ?
Dichlorodifluoromethane                            ?
Trichlorofluoromethane                             ?

Haloeenated Ethers

Bis(choromethyl) ether
Bis(2-chloroethyl) ether
Bis(2-chloroisopropyl) ether
2-Chloroethyl vinyl ether                          -
                                                               •H-

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                                                       TABLE  2 (Continued)
                                                                                         Process
                  Compound
                                                          Sorotion Volatilization  Blodegradation  Photolvsis-Dlrect	Hydrolysis
oo
 Halogenated Ethera  (Concluded)

 4-Chlorophenyl phenyl ether
 4-Bromophenyl phenyl ether
 Bls(2-chloroethoxy) methane

 Monocvcllc Aromatlcs

 Benzene
 Chlorobenzene
 1,2-Dlchlorobenzene (o-dlchlorobenzene)
 l-3,Dlchlorobenzene (m-dichlorobenzene)
 1,4-Dlchlorobenzene (p-dichlorobenzene)
 1,2,4-Trichlorobenzene
 Hezachlorobenzene
 Ethylbenzene
 Nitrobenzene
 Toluene
 2,4-Dinitrotoluene
 2,6-Dinitrotoluene
 Phenol
 2-Chlorophenol
 2,4-Dlchlorophenol
 2,4,6-Trlchlorophenol
 Pentachlorophenol
 2-Rltrophenol
 4-Hltrophenol
 2,4-Dinitrophenol
 2,4-Dlmethylphenol (2,4-xylenol)
B-chloro-m-cresol
4,6-Dlnltro-o-cresol

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                                               TABLE 2  (Continued)
        Compound
                                                                               Process
Sorption Volatilization  Biodeeradation  Photolysis-Direct  Hydrolysis
Phthalate Esters

Dimethyl phthalate
Diethyl phthalate
Di-n-butyl phthalate
Di-n-octyl phthalate
Bis(2-ethylhexyl) phthalate
Butyl benzyl phthalate

Polycyclic Aromatic Hydrocarbons

Acenaphthene3
Acenaphthylene3
Fluorene3
Naphthalene
Anthracene
Fluoranthene3
Phenanthr ene3
Benzo(a)anthracene3
Benzo(b)fluoranthene3
Benzo(k)fluoranthene3
Chrysene3
Pyrene3
Benzo(ghi)perylene3
Benzo(a)pyrene
Dibenzo(a,h)anthracene3
Indeno(1,2,3-cd)pyrene3

Nitrosamines and Misc.  Compounds

Dimethylnitrosamine
Diphenylni t rosamine

-------
                                               TABLE  2 (Concluded)
                                                                                Process
	Compound	Sorptlon  Volatilization  Biodegradatlon  Photolysis-Direct—Hydrolysis

Nltrosamlnea and Misc. Compounds (Concluded)

Di-n-propylnitrosamine                             -            -               -                ++
Benzidine                                          +            -               ?                -f
3,3^- Dichlorobenzidine                             -H-           -               -                +               ~
1,2-Dlphenylhydrazine (Hydrazobenzene)             +            -               ?                +               -
Acrylonitrile                                      -            +               1                -


Source:  Hills et al. (1985).

 •fCould be an important fate process.
•f+Predominate fate determining process.
 -Rot likely to be an important process.
 ?Importance of process uncertain or not  known.

Ifiiodegradation is the only process known to transform polychlorinated bipenyls under environmental conditions, and
 only the ligher compounds are measurably biodegraded.   There is experimental evidence that the heavier polychlorinated
 biphenyls (five chlorine atoms or more per molecule) can be photolyzed by ultraviolet light,  but there are not data to
 indicate that this process is operative  in the  environment.
2Based on information for 4-nitrophenol.
3Based on information for PAHs as a group.   Little  or no information for these compounds exists.

-------
fate of a substance in the aquatic environment.  The decay processes

are generally expressed as kinetic processes; sorption is generally

described as an equilibrium process (Fiksel and Segal, 1982, and

Delos et al., 1984).  The five decay processes are described

together in Section 2.2 and sorption is described in Section 2.3.

These formulations are used in Section 3 for modeling the combined

effect of all these processes on the fate of substances in the two

types of surface water.

2.2  Biodegradation, Hydrolysis, Photolysis, Free-Radical Oxidation,
     and Volatilization

     Biodegradation, hydrolysis, photolysis, free-radical oxidation,

and volatilization are generally regarded as irreversible loss

processes for hazardous substances (Delos et al., 1984).  The loss

rates are often expressed in terms of first-order kinetics because

of the low concentrations of hazardous substances expected in the

environment (Mabey et al., 1982).  The first-order decay

coefficients for individual processes are additive; together they

form an aggregate decay coefficient:

            Y = Y+Y+Y+Y+Y
                 B    H    P    V    0
where "Y  = Aggregate decay rate, in
      VB - Biodegradation rate, in (time)"1
      YJJ = Hydrolysis rate, in (time)"-*-
      Yp = Photolysis rate, in (time)"1
      Vv = Volatilization rate, in (time)"1
      YQ = Free-radical oxidation rate, in (time)"-'-

     This aggregate decay coefficient can be taken as a measure of

the persistence of the substance if sorption is not considered.  An
                                  21

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alternative way to describe the persistence of a hazardous substance

is to calculate its half-life (Mabey et al., 1982).  The half-life

^1/2^ is tne Ien8tn of time required for the initial concentration

to be halved as a result of the decay loss.  The half-life of a

hazardous substance is not dependent on the initial concentration for

the first order kinetics and is calculated by means of  the following

equation:

                           t1/2 - (In  2)/Y                       (2)
or it may be  calculated  from the  individual half-lives:

tl/2  " 	L	:	-	_
                                                                   (3)
                                             (ti/2>V     0

where  (ti/2)fl  = Biodegradation half-life,  defined  as  (In 2)/YB
       (t1/2)n  = Hydrolysis  half-life,  defined as  (In  2)/YH
       (ti/2)p  = Photolysis  half-life,  defined as  (In  2)/Yp
       (t1/2)y  = Volatilization half-life,  defined  as  (In 2)/Vv
               = Oxidation half-life, defined as  (In 2)/V0
      Table 3 shows  the percent  of substance remaining as a function

 of the number of  half-lives  elapsed.

      The feasibility of using half-life,  as defined above, as a factor

 in the HRS to account  for environmental attenuation of substances

 depends on the amount  of data available.   Fortunately, the half-life

 may be estimated  for a large number of hazardous substances,  and it is

 possible to rank  the persistence of hazardous substances based on

 their estimated half-lives.   Appendices B and C present illustrations

 of the estimated  half-lives  for over 250  substances in streams and

 rivers and in lakes and reservoirs, taking into account biodegrad-


                                  22

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                    TABLE  3

PERCENT OF A SUBSTANCE REMAINING AS A FUNCTION
      OF  THE NUMBER  OF HALF-LIVES  ELAPSED
   Number of Half-         Percent Substance
    Lives Elapsed	Remaining	

        0.11                      90

        1.0                       50

        2.0                       25

        3.3                       10

        4.3                        5

        6.6                        1

       10.0                        0.1

       13.0                        0.01
                      23

-------
ation, hydrolysis, photolysis, volatilization, and free-radical




oxidation as appropriate.  The only difference between the two




tables results from the fact that the volatilization half-life of a




substance in streams and rivers is different  from that in lakes and




reservoirs  (Lyman et al., 1982 and IGF, 1984).




     Estimated decay rates (or half-lives) have  in the past been




used for screening purposes  (Fiksel and Segal, 1982; ICF, 1984; and




Mabey et al., 1982).  This is especially  useful  for ranking the




persistence of substances in streams and  rivers.  As shown in




Section 4,  because of the short expected  travel  time within the




target distance  limit, the effects of these decay processes are




insignificant for substances with half-lives  longer than one day.




Thus, there is no need to discriminate among  substances with half-




lives longer  than one day.   It should be  noted that in Appendices B




and C, a default value of 999 days is assigned to metals to represent




their persistent nature.  In the case of  metals, as well as other




elements,  the only applicable decay process for  estimating




persistence is volatilization because elements are conserved in




transformation reactions.




      The majority of the information used to  derive Appendices B




and C was  collected from four sources:  (1) "Exposure Profiles




Prepared in Support of RCRA  Risk-Cost Analysis Model" (Environ,




1984);  (2)  "Screening Hydrolytic Reactivity of OSW Chemicals"




 (Wolfe, 1985);  (3)  "Physio-Chemical Properties and Categorization of






                                  24

-------
RCRA Wastes According to Volatility" (U.S. EPA, 1985); and




(4) "Technical Background Document to Support Rulemaking Pursuant to




CERCLA Section 102, Volumes 1, 2 and 3" (Environmental Monitoring




and Services, Inc., 1985).




     The first source provides estimated half-lives for 58 organic




substances in the surface water environment.  The second source gives




values for the Henry's constants of the substances; these were then




used to estimate the volatilization half-lives of the substances.




The third source addresses the hydrolytic reactivity of many




hazardous organic compounds listed in Appendix VIII of the RCRA




Subtitle C Hazardous Waste Regulations (40 CFR 261).  The fourth




source provides a review of biodegradation, hydrolysis and




photolysis.  Most of the information from this source is qualitative;




nonetheless, it is useful in identifying substances with expected




half-lives longer than five days.




2.3  Sorption




     Surface water always carries with it some suspended load.




Suspended load refers to particles which are carried into the main




flow and lose contact with the river or lake bed.  These particles




travel at a velocity almost equal to the flow velocity (Garde and




Ranga Raja, 1977).  They interact with substances in water through




sorption and may influence the aqueous fate of those substances.




The fate of a sorbed substance is closely related to the fate of the




suspended solid material onto which it is sorbed.  As the suspended






                                  25

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solids settle out of the water column, they carry along with  them

the sorbed substances.  As they are re-entrained, they also carry

with them the sorbed substances.

     In modeling the environmental fate of substances, sorption is

generally considered to be an equilibrium partition between the

water and suspended solids.  The sorption potential of a substance

is often characterized by the partition coefficient (K ) of the

substance, which is defined as follows:



                          K'-t

where r is the sorption density, (i.e., the amount of substance

sorbed  per unit mass of solid), and C, is the remaining substance

concentration in solution (i.e., the  dissolved substance

concentration).

      Sorption density is calculated by dividing  the sorbed

particulate  substance concentration (C ) by the  suspended solid

concentration (SS).   Therefore, the partition coefficient is also

expressed  as:

           K _  Particulate substance concentration/(SS)
                    Dissolved substance concentration

      Since the interest of this study is to estimate  the ratio

 between the  particulate and dissolved substance  concentrations,

 equation (5) is  rearranged to:
 Particulate substance concentration   _£ = _   (GO)
  Dissolved substance concentration   C,   p
                                   26

-------
Alternately,
     Dissolved substance         Dissolved         Total Substance
                           •                  x
       concentration             fraction           concentration

                   that Is,    C  _       1
                                     K  (SS) + 1 "
                                      P
     Particulate           m     Particulate       Total substance
       substance                  fraction          concentration
       concentration

                               r      K  (SS)
                   that is,     p - R  ?ss)+1 C                   (8)
                                     P

     It needs to be stressed here that the product of solid concen-

tration (SS) and partition coefficient (K ) defines the distribution

of a substance between the dissolved phase and the particulate phase.
                                   3
Thus, a partition coefficient of 10  I/kg does not indicate the

relation of the particulate substance concentration to the dissolved

substance concentration.  Rather the value of 10  I/kg would have to

be multiplied by the solid concentration (e.g., 200 mg/1 or 2 x 10

kg/1) to obtain a ratio of 0.2.  In fact, particulate substance

concentrations range from 0.02 to 0.5 of the dissolved substance

concentrations in typical U.S. streams and rivers with suspended

solids ranging from 20 to 500 mg/1 (Britton et al., 1983).

     The effect of sorption is much less in surface water than in

ground water.  In ground water the major interacting solid phase is

the soil or rock matrix, the concentration of which far exceeds the

suspended solids concentrations typically encountered in surface

waters.  Moreover, since the suspended solids travel at virtually
                                  27

-------
the same velocity as the surface water flow, sorption would not
affect the total chemical concentration in surface waters until
there is a net loss of the particulate substance from the water
column due to sedimentation (Delos et al., 1984).
     In the absence of actual data, a partition coefficient  (K )
can be estimated using the methods described in Sections 2.3.1 and
2.3.2, incorporating basic environmental  parameters  and readily
available information on substances.
2.3.1  Organics
     Most of the organic chemicals of concern under  CERCLA are
hydrophobic, unionized compounds with only a limited degree  of
polarity.  The sorption of these chemicals on natural particles
 (such  as  soils or suspended solids or sediments in streams)  is
primarily driven by their hydrophobic nature and,  therefore, is
 dependent on  the organic content of the particles  (Karickhoff,
 1984).   For  such cases, Karickhoff  (1984) suggested  that the
 partition coefficient K  be related empirically to the
 octanol-water  partition coefficient  (K  ) of the  chemical  and the
                                      ow
 organic  carbon  fraction of the  particle (f   ) as  follows:
                        Kp = 0.41 x KOW x foc                     (9)
 Measured values of  K  for organic  chemicals have  been found as  low
      -3                   7
 as 10   and  as  high as 10  , encompassing  a range  of  ten  orders of
 magnitude.   Several methods are available for calculating  K   from
 the physical and chemical  properties of the  chemical.  It  is possible
                                   28

-------
to estimate log K   with an uncertainty of no more than 0.1 to




0.2 logarithm units (or from 25 to 50 percent of the K   value)




(Lyman et al., 1982).  Appendix D lists log K   values for a




number of hazardous substances frequently encountered at NPL sites.




2.3.2  Metals




     Many studies have been made to help assess, monitor and control




metals present in surface water.  In these studies, metals are




generally reported in two fractions:  the dissolved and the




particulate fractions.  From the distribution of metals in the




dissolved and particulate fractions, Forstner and Wittmann (1979)




suggested that the alkali metals and alkaline earth metals, such as




sodium and calcium, are present predominantly in dissolved form;




iron and aluminum (and manganese under normal conditions in rivers)




are almost totally transported by means of solid particles; and




trace metals, such as cadmium and zinc distributions, are present in




both forms.




     A more recent and extensive analysis of water-sediment




partition coefficients for priority pollutant metals was conducted




by HydroQual (Delos et al., 1984).  Data were retrieved from the




water quality file STORET, a computer database maintained by EPA.




Overall, approximately 20,000 data points on nine priority metals




were available for analysis.




     One objective of the HydroQual study was to calculate partition




coefficients for priority metals and, wherever possible, to relate
                                 29

-------
the coefficients to appropriate environmental variables.  HydroQual

concluded that:

     •  A pronounced relationship exists between partition
        coefficients for the various priority metals and suspended
        solids concentrations.

     •  No consistent correlation was found among partition
        coefficients and other environmental factors, including pH,
        alkalinity, temperature or BOD.

     Since first noted by Kurbatov et al.  (1951), pH has been

considered the primary variable that governs the extent of inorganic

adsorption (Schindler, 1981).  Therefore,  the absence of pH effect

observed in the HydroQual study calls for  careful evaluation.  An

analysis of this phenomenon is provided in Appendix E.

     The regression results from the HydroQual study are summarized

in  Table 4.   In this table, the partition  coefficient (K ) is

expressed as  a function of suspended solids concentration (SS) as

follows:

                             K  = a(SS)b                          (10)

     The values of a and b differ with the type of metal and the

type of water body.  This simple relationship allows the partition

coefficient of metals to be calculated from suspended solids

concentration.

     Substituting equation (10) into equation (6), the  following

relationship  is obtained:

     Particulate metal concentration       1+b                    (11)
       Dissolved metal concentration
                                  30

-------
                                        TABLE 4

            EMPIRICAL RELATIONSHIP BETWEEN METAL PARTITION COEFFICIENT (Kp)
                        AND SUSPENDED SOLIDS CONCENTRATION (SS)
Streams
Metal
Arsenic
Cadmium
Chromium
Copper
Lead
Mercury
Nickel
Silver3
Zinc
No. of
Records
1635
254
345
2722
1545
369
1394
—
2253
a
0.48xl06
4.00xl06
3.36X106
1. 04x10 6
0.31xl06
2.91xl06
0.49xl06
—
1.25xl06
b1
-0.7286
-1.1307
-0.9304
-0.7436
-0.1856
-1.1356
-0.5719
—
-0.7038
2
-0.993
-0.998
-0.914
-0.994
-0.350
-0.990
-0.974
—
-0.995
No. of
Records
1
296
211
577
411
169
285
—
914
Lakes
a
	
3.52X106
2.17X106
2.85xl06
2.04X106
1.97xl06
2.21xl06
—
3.34xl06
b1
—
-0.9246
-0.2662
-0.9000
-0.5337
-1.1718
-0.7578
—
-0.6788
2
—
-0.993
-0.818
-0.955
-0.965
-0.962
-0.970
—
-0.849
!KP = a(SS)b, where Kp is in the units of liter Kg/SS is in the unit of ing/liter.
^Correlation coefficient.
^Insufficient data to perform regression.

Source:  Delos et al., 1984.

-------
Since b is negative for all metals studied, equation (11) suggests




that the distribution of metals in the particulate and dissolved




phases may become less dependent on the concentration of suspended




solids.  This is especially true for cadmium (b = -1.13), chromium




(b = -0.93), and mercury (b = -1.14).  For these three metals, the




ratio of particulate metal concentration to dissolved metal




concentration almost becomes independent of suspended solids




concentration.



     Table 5 presents calculated values of the partition coefficient




and  dissolved and particulate fractions of selected priority metals




in streams and rivers at several specified suspended solids




concentrations.  The partition coefficient decreases with an




increase  of solids  concentration for all metals listed.  However,




the  distribution of metals between the dissolved and particulate




phases  is less dependent on the solids concentration, particularly




for  cadmium, chromium and mercury.  Over a range of 1 to 500 mg/1




suspended solids concentration, the particulate fractions of cadmium,




chromium and mercury differ by less than 20 percent and for all




practical purposes, it may be assumed that the particulate/dissolved




distributions of the three metals are insensitive to suspended solids




concentration in this range.




2.4  Effect of Sorption on Other Transformation Processes




     Substances sorbed on a solid enter a microenvironment, which is




governed by the surface characteristics of the solid.  This
                                  32

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                            TABLE 5

CALCULATIONS OF DISSOLVED AND PARTICULATE FRACTIONS OF SELECTED
 PRIORITY METALS IN STREAMS AT SPECIFIED SOLID CONCENTRATIONS

Arsenic



Cadmium



Chromium



Copper



ss1
mg/1
1
50
200
500
1
50
200
500
1
50
200
500
1
50
200
500
K2
1/ig
4. 8x10 5
2.8xl04
l.OxlO4
5.2xl03
4.0xl06
4.8xl04
l.OxlO4
3.6xl03
3.36xl06
8.8xl04
2.4xl04
l.OxlO4
1.04xl06
5.7xl04
2.0xl04
l.OxlO4
3
Dissolved
Fraction
0.68
0.42
0.33
0.28
0.20
0.29
0.33
0.36
0.23
0.18
0.17
0.16
0.49
0.26
0.20
0.16
A
Particulate
Fraction
0.32
0.58
0.67
0.72
0.80
0.71
0.67
0.64
0.77
0.82
0.83
0.84
0.51
0.74
0.80
0.84
                              33

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                          TABLE 5 (Concluded)
ss1
mg/1
Lead 1
50
200
500
Mercury 1
50
200
500
Nickel 1
50
200
500
Zinc 1
50
200
500
K2
l/ig
3.1xl05
l.SxlO5
1.2xl05
9.8xl04
2.91xl06
3.4xl04
7. 1x10 3
2. 5x10 3
4.9xl05
5.2xl04
2.4xl04
1.4xl04
1.25xl06
S.OxlO4
3.0xl04
1.6xl04
Dissolved
Fraction
0.76
0.12
0.04
0.02
0.26
0.37
0.41
0.44
0.67
0.28
0.17
0.12
0.40
0.20
0.14
0.11
4
Particulate
Fraction
0.24
0.88
0.96
0.98
0.74
0.63
0.59
0.56
0.33
0.72
0.83
0.88
0.60
0.80
0.86
0.89
^-Suspended solids concentration in stream.
2Partition coefficient, calculated from regression equations  in
 Table 4.
3Calculated as [Kp (SS) + I]'1.
4Calculated as (1.0 - dissolved fraction).
                                  34

-------
microenvironment differs from the bulk aquatic environment.  The




sorbed substance, therefore, is likely to have reaction rates




different from those of the dissolved substance, but it is not




always possible to estimate the extent or direction of these




differences.




     Baughman et al. (1980) showed that the dissolved fraction of




the compounds studied was available for biodegradation while the




particulate fraction was not.  On the contrary, Mills et al. (1985)




suggested that, since bacteria grow readily on the surface of solid




particles, the presence of sediment can increase the rates of




microbial metabolism.  The volatilization rate is a function of the




dissolved substance concentration; therefore, the presence of




particulate material slows down volatilization by reducing the




concentration of the dissolved chemical (Mackay and Shiu, 1984).




Neutral hydrolysis rates for several organic chemicals were found to




be the same for both the dissolved and the sorbed chemical, but




alkaline hydrolysis rates were found to be slower for the sorbed




chemicals (Macalady and Wolfe, 1984).  Zepp and Scholtzhauer (1981)




reported that the photolysis rates of DDE sorbed on aqueous




suspension of well-characterized sediments are affected by the




length of time that the DDE is sorbed on the sediments.  The DDE is




sorbed onto two types of sediment sites—sites at which DDE reacts




at a higher rate than when it is dissolved in water; and other sites




at which the chemical is nonreactive.  Thus, the overall photolysis






                                  35

-------
rate becomes limited by diffusion of DDE from the unreactive to the




reactive sites.




     These difficulties indicate that it is not possible to




generalize as to the effect of sorption on other transformation




processes.  A conservative approach is taken in this report which




assumes zero decay by means of biodegradation, hydrolysis,




volatilization, free radical-oxidation, or photolysis for the sorbed




substances.
                                 36

-------
3.0  MODELS OF SUBSTANCE FATE FOR IDEALIZED WATER BODIES




3.1  Overview




     Simple fete and transport models are used in this section to




illustrate the effect of the various loss processes on the persistence




of a substance in surface water.




     Persistence of a substance may be defined as the capability of a




substance to resist a reduction of its concentration despite the




several loss* processes acting upon it by the environment.  Therefore,




the persistence of a substance, if evaluated over a specified distance,




is related to the reduction of the substance concentration over that




distance.  In this presentation, a logical choice for this distance of




interest is the target distance limit in the surface water pathway




which is currently defined as 3 stream miles (or 1 mile in static




surface water, such as a lake) downstream of the probable point of




entry to surface water or downstream of the furthest measurement




supporting an observed release (40 CFR 300, 47 FR 31180, July 16,




1982).  As a result, the models described in this section are formu-




lated with the objective of estimating the change of a substance




concentration over those distances.  The loss processes incorporated




in the models are:
*Dilution is not considered a loss process in this report.





                                 37

-------
     •  The decay processes—biodegradation, hydrolysis,  photolysis,
        volatilization and free-radical oxidation.

     •  The sedimentation loss of the sorbed chemical.*

     In the HRS, surface water is classified into two broad categories:

streams/rivers and lakes/reservoirs.  The primary difference in the

hydrodynamic properties of these two classes of water bodies is that

streams and rivers tend to be advection dominated, whereas lakes and

reservoirs tend to be dispersion dominated.  Consequently, a one-dimen-

sional model** (with the axis taken along the direction of the flow in

stream) is often used to describe streams and rivers and a fully mixed

system is often used to describe lakes and reservoirs (Thomann, 1972).

3.2  Streams and Rivers

     The model described in this section is the standard one-dimen-

sional, steady-state model (Thomann, 1972).  It predicts the steady-

state concentration (cross-sectionally averaged) profile along the

river reach downstream of the substance entry point.
 *For purposes of developing options, this paper treats sorption
  followed by settling as a loss process.  However, hazardous
  substances which are removed from the water column by sorption and
  sedimentation may still be available to ecosystems through uptake
  by benthic organisms.  Also, the hazardous substances may be
  available to human populations and ecosystems through resuspenslon.
  Consequently, EPA may not wish to treat sorption followed by
  settling as a loss process.  Options presented in Chapter 4 allow
  for both possibilities.
**A one-dimensional model does not describe the variation of concentr-
  ation over the cross-section of the stream and river.   Such a model
  is applicable in describing the variation of a concentration which is
  averaged over the cross-section,  or in regions where  the substance is
  fully mixed across the cross section such as in region downstream of
  the mixing zone.


                                 38

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     3.2.1  General Model, Considering Both Settling and Decay



     Figure 1 is a schematic diagram of the model.   The total



substance concentration (C) in the water column consists of two



parts — the dissolved substance concentration (C,) and the



particulate substance concentration (C ).  The dissolved and the



particulate substances are assumed to be in equilibrium partition as



previously described in equations (7) and (8) which are as follows:
                        d   i + K
                                 P
                                                                 (7)

                                                                 v"
                              K  (SS)

                                        C                        (8)
                        P   l + K


The dissolved substance decays at a rate   which represents the sum



of all the decay processes described in Section 2.2.   Since this



study assumes no decay loss for particulate substances (Section 2.4),



the particulate substance is considered to be lost through settling



at a rate g, which is the same as the settling loss rate of



suspended solids (SS).  Both Y and g are in units of (time)



Assuming that the longitudinal dispersion is negligible (Fischer



et al., 1979), the equations which describe the variation of the



substance and suspended solids concentrations along the river reach



during the steady-state are as follows:




                       - ai • -* CP -
                       u d      - -g (SS)                        (13)




where:  x ** Distance downstream of the entry point of the chemical.

        u = Mean flow velocity.
                                 39

-------
            SUBSTANCE:
          Decay Loss Rate (r)
                   Total Substance Concentration (C)
              Dissolved
             Substance
            Concentration
                (Cd)
Equilibrium
 Partition
 Paniculate
 Substance
Concentration
   (Cp)
                           C = Cd +
                                             Sedimentation
                                                Rate
                                                 (9)
            SUSPENDED SOLIDS:
                                    Sedimentation
                                       Rate
                                        (g)
                            FIGURE 1
A SCHEMATIC DIAGRAM SHOWING THE IMPORTANT PROCESSES
AFFECTING FATE OF SUBSTANCES IN A SURFACE WATER BODY
                               40

-------
Equation  (12) may  be  solved  using the  solution  for  SS, as well as

equations  (7) and  (8).  The  solution for  SS  is:
                        SS  .    ~8 u                                (14)
                        SSo
 and  the  solution  for  C  is:
                         -V*          -8
                  C       u  1 +  e    U
                       e
with   a = Kp-SS0

where Co = Total substance  concentration at the entry point of
           the  substance  (i.e., at x = 0).
     SS0 = Suspended solids  concentration at the entry point of
           the  substance  (i.e., at x = 0).
       x = Travel  time; the  time required by substance to travel
       u   from the entry point to a point at x distance downstream.

     The sedimentation rate  g, needed for the calculation of C,

generally is not known beforehand, but is calibrated with field data

on suspended solids concentration using equation (14).  In the

remainder of this  report, when information on sedimentation rate is

indicated as necessary, the  measurement of suspended solids

concentration needs to be made at more than one location so as to be

a representative measurement.

     3.2.2  Model  With Decay Only

     In some instances , sedimentation is not a significant loss

process either because the substance of interest has little sorption

potential, because limited sedimentation has occurred between the
*In the case of metals, whose Kp has been found to be a function of
 SS, a different solution is needed and is presented in Section 3.2.4.

                                  41

-------
two locations at which suspended solids concentrations have been

measured, or because of the reasons indicated in Section 3.1.   The

solution for these cases may be obtained by letting g approach zero

in equation (15).  A simpler way to find the solution is to

reformulate the governing equation for this simplified case by

dropping the sedimentation loss term from equation (12):


                      u ^2 = _YC.                                (16)
                        dx      d

There is no need to write an equation for SS because, with no

settling SS remains constant with distance.  Therefore, equation (16)

is solved by substituting equation (7) into it and the solution for

C becomes:


                      r      ~YfH £
                      £- = e    d U                              (17)
                       o

where f                      as)
                                 42

-------
     3.2.4  Model With Settling Only, With Partition Coefficient as

            a Function of Suspended Solids Concentration


     This special case of the possible decay processes illustrates


the effect of very long persistence for selected substances.  In


particular, this case shows how metals, which are of interest due to


their potential hazard, might behave.


     The partition coefficients for metals have been shown to be a


function of suspended solids concentration (Section 2.3.2):


                             K  = a(SS)b                          (10)
                              P

where a and b are regression coefficients given in Table 4.  The


relationship between the dissolved and the particulate metal


concentrations is :


                         C         1 + b

                         7^ = a(SS)                              (11)
                         Cd


or we may write:
                              1 + a(SS)1 + b


The equation which describes the change of SS remains the same:
                         u d ^J/ = -g (SS)                      (13)



The governing equation for C is simplified from equation (12) by


dropping the decay loss term:




                    U ll = ~8 Cp                                 (20)


This equation may be solved by using the solution for SS that is,


equation (14) and by using equation (19).  The solution for C is:




                                 43

-------
                         - -       a * Pe           ,



where p - a(SSo)1+b


3.3  Lakes and Reservoirs


     The model is a  standard  steady-state model and it considers a


lake as a fully raised  tank reactor with  constant inflow and


outflow.  That is, there is no  concentration  gradient in the lake


and the outflow concentration is  the same as  the concentration in


the lake.  It describes  the steady-state (lake concentration)


averaged over the lake volume of  interest*  in relation to the


external input.  Figure  2  is  the  definition sketch of the idealized


lake or reservoir under  this  model assuming contaminants are brought


into the lake at concentration  C. by the inflow.  As in the case


in streams and rivers, the  total  substance  concentration (C) in the


water column of lakes  and reservoirs consists of two parts—the


dissolved substance  concentration (C,) and  the particulate


substance concentration  (C  ).   The dissolved  and the particulate


substances are assumed to be  in equilibrium partition as described
in equations  (7) and  (8):



                        C.
                               + K  (SS)
                                  P

                               K  (SS)
                        r  =    P        r
                         p   1 + K  (SS) L
*Refers to the lake volume within the specified target  distance  limit.



                                 44

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    Inflow
(Concentration Cj)
Mixing
           Decay Loss Rate (r)
\ Total Substance Concentration (C)
Dissolved
Substance
(Cd)

Equilibrium
Partition
C = Cd + Cp
Partk
Subs
(C

;ulate
tance
ntration
p)

                  Outflow
               (Concentration C)
                                      Sedimentation
                                         Rate
                                         (9)
                             FIGURE 2
      A SCHEMATIC DIAGRAM SHOWING THE IMPORTANT PROCESS
AFFECTING FATE OF SUBSTANCES IN AN IDEALIZED LAKE OR RESERVOIR
                                45

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     The dissolved substance decays at a rate   which represents the

sum of all the decay processes described in Section 2.2.  Since this

study assumes no decay loss for particulate substances  (Section 2.4),

the particulate substance is considered to be lost through settling

at a rate g, which is the same settling loss rate of suspended

solids (SS).  Both V and g are in units of (time)  .

     At steady state, the relationships between  the inflow concen-

trations of substance (C.) and suspended solids  (SS.) and the

volume-averaged concentration of substance (C) and suspended solids

(SS) in lakes and reservoirs are described by the following equations:

                   0 = Q (C -C) -g  C  - C.                       (22)
                       V   i        P    d

                   0 = Q (SS -SS) -g (SS)                        (23)
                       V    i

where:  Cj_  = Inflow concentration.
        C   = Average substance concentration in the volume of water.
        V   = Volume of the water defined from the inflow location to
              the target distance limit.  During the stratification
              period, this only refers to the volume which lies above
              the thermocline.
        Q   = Flow rate.
        SS^ = Inflow suspended solids concentration.
        SS  = Average suspended solids concentration in the volume of
              the water.

The solution for C is:

                   C_ = 	1	                         (24)
                   C±   1 + fpg 4- fdY)  T

and the solution for SS is:

                         SS  -   1                               (25)
                               1 + gT
                                 46

-------
where T is the hydraulic retention time, defined as V/Q, f  is the


particulate fraction of the substance, f, is the dissolved fraction of


the substance.  The values of f  and f, are calculated as follows:
                               P      d

                             K  (SS)

                      fp = Kp ?SS> + 1                              (26)




                      fd = K  (SS) + 1                              (26)
                            P


where K  is partition coefficient which may be estimated using


equation (9) for nonpolarized organics, or estimated by using


equation (10) and coefficients in Table 4 for priority pollutant


metals.


     If no settling takes place (i.e., g = 0), the solution for C is


simplified to:


                   C_ =     1                                    (28)

                   ci   1 + fd ^T


     If no decay takes place (i.e., Y = 0), the solution for C is:


                   C_ =     1                                    (29)

                   C±   1 + f p gT
                                 47

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4.0  ALTERNATIVES TO THE CURRENT HRS PERSISTENCE RANKING METHOD FOR
     THE SURFACE WATER PATHWAY

4.1  Overview

     This section describes two persistence ranking methods which

may be used as alternatives to the current HRS method.  Both

alternatives are based on the expected reduction of the substance

concentration over the target distance limit.*  The less the

reduction of concentration as a result of the loss processes

identified in Section 2, the greater the substance's persistence is

deemed to be and the higher the rating value assigned to it.  The

first alternative considers the joint effect of sorption,

biodegradation, hydrolysis, photolysis, volatilization, and

free-radical oxidation.  The kinetic information on the latter five

processes has been compiled in Appendices B and C.  The settling

loss of substances through sorption, however, cannot be quantified

without site measurement.  If EPA decides not to consider settling

as a loss process or if it is not practical within CERCLA site

inspections to require additional site measurement to determine the

settling loss, a second alternative is proposed which ranks

substances according to only biodegradation, hydrolysis, photolysis,
*The target distance limit in the surface water pathway is defined as
 3 stream miles (or 1 mile in static surface water, such as a lake)
 downstream of the probable point of entry to surface water or down-
 stream of the last measurement of an observed release in streams
 or rivers.
                                 49

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free-radical oxidation, and volatilization.  In both alternatives,




the appropriate equations from Section 3 are used to calculate the




expected reduction in concentration of substances in both streams




and rivers and in lakes and reservoirs.




     Four ranking categories are proposed for both alternatives.




These categories are as follows:  "persistent," if the reduction in




concentration is less than 50 percent over the target distance




limit; "moderate," if the reduction in concentration is between




50 percent and 90 percent over the target distance limit; "low," if




the reduction in concentration is between 90 percent and 99.9 percent




over the target distance limit; "nonpersistent," if the reduction in




concentration is greater than 99.9 percent over the target distance




limit.




     The two methodologies are described in the following sections




according to the type of water body and the type of substance of




interest.  Whenever possible, a sensitivity analysis section is




provided to offer preliminary assessment of the relative importance




of some parameters.




4.2  Alternative I




     This alternative considers the effects of both sorption and




decay processes.  The procedure for ranking substances differs




according to the type of substance (metals vs. organics) and the




type of water body concerned (streams and rivers vs. lakes and




reservoirs).
                                 50

-------
     4.2.1  Streams and Rivers

     The details of the proposed Alternative I ranking method are

shown in Figure 3.

     4.2.1.1  Metals.  In streams and rivers, if the substance of

concern is a metal, equation  (21) is used to calculate C/C .

Based on the value of C/C , the metals are classified in one of

the four rank categories:

                Rank                   Criteria

            Persistent            0.5   < C/CO
            Moderate              0.1   < C/C0 < 0.5
            Low                   0.001 < C/C0 < 0.1
            Nonpersistent                 C/CO < 0.001

     Five parameters are needed for the calculation:  suspended

solids concentration at the beginning and the end of thte target

distance limit, travel time within the target distance limit, and

coefficients a and b for estimating the partition coefficient.  The

travel time can be estimated  from flow velocity.*  In the absence of

an explicit measurement, a default value of 0.1 days is recommended,

which is a representative three-mile travel time in streams and

rivers (Appendix F).  The values of a and b are given in Table 4.

The two suspended solid concentrations must be measured.

     4.2.1.2  Organics.  The  expected concentration change is

calculated using equation (15), which considers the simultaneous
*Flow velocity varies with time.  Choice of the period during which the
 measurement is made should be based on the degree of conservativeness
 intended.

                                  51

-------
                                      Streams/Rivers
                Metals
      Calculate C/C0 using Eq.(21)
        Persistent; if C/GO> 0.5

        Moderate; if 0.5> C/CQ> 0.1

        Low; if 0.1 >C/C0> 0.001

        Non-persistent; if 0.001 > C/C0
               Organics
      Calculate C/Q, using Eq.(15)
      •  Persistent; if C/Co> 0.5

      •  Moderate; if 0.5>C/CQ> 0.1

      •  Low; if 0.1>C/Co> 0.001

      •  Non-persistent; if 0.001 >C/C0
      Parameters:

     • Two suspended solids concentrations
       within the target distance limit
     • Travel time1
     • Coefficients a, b^
 Parameters:
• Two suspended solids  concentrations
  within the target distance limit
• Partition coefficients
• Half-life 4
* Travel time
• Organic carbon fraction of the
   suspended solids
1 A value of 0.1 days is recommended based on the current MRS target distance limit (See Appendix  F).
* Available in Table 4
^ Calculated as (0.41 x KQWX fow ); KQW  values are available in Appendix D.
4 Calculated as 0.693/half-life; illustrations of the values of half-lives are available from Appendix B.
                                         FIGURES
                  PERSISTENCE RANKING METHOD FOR SUBSTANCES
                        IN STREAMS AND RIVERS - ALTERNATIVE I
                                          52

-------
effect of decay loss and sedimentation loss resulting from sorption.

An appropriate simplified equation [equation (17) or (18)] may be

used to replace equation (15), if either decay loss or sedimentation

loss dominates the fate of the substance.

     The substance are classified into four rank categories according

to the same criteria used to classify metals:

                Rank                 Criteria

              Persistent          0.5   < C/CO
              Moderate            0.1   < C/CO < 0.5
              Low                 0.001 < C/C0 < 0.1
              Nonpersistent               C/CO < 0.001

     Six parameters are needed for the calculation:  suspended solids

concentration at the beginning and the end of the target distance

limit, travel time within the target distance limit, decay loss rate,

octanol-water partition coefficient and organic carbon fraction of the

suspended solids.  The last two parameters are used to estimate the

partition coefficient of organic substances by means of equation (9):

                 Kp = 0.41 x foc x KQW                           (9)

     The values of K   for a number of substances can be obtained
                    ow

from data in Appendix D.  The decay loss rate can be estimated from

the half-life (t,/2) of th£ substance by:

                         Y _ 0.693                               (30)
                           " ti/2

Illustrations of half-lives in streams and rivers are listed for more

than 250 substances in Appendix B.  The travel time can be estimated

from measurement of flow velocity.  In the absence of measurement, a
                                  53

-------
value of 0.1 day is recommended, which is a representative three-




mile travel time in streams and rivers (Appendix F).




     In addition to these data, the organic fraction of the suspended




solids and the two suspended solids concentrations must be measured




to evaluate either metals or organics.  In comparison with the




metals, organic substances require one additional measurement—the




organic carbon fraction of the suspended solids.  For both metals




and organics, these measurements are necessary in order to quantify




the effect of sorption.




     4.2.1.3  Sensitivity Analysis




     Decay Loss




     Assuming 0.1 days of travel time, in the absence of settling




loss, a substance needs to have a half-life of less than 0.1 days to




be ranked other than persistent (e.g., moderate).  Of the more than




250 chemicals listed in Appendix B, only 18 chemicals (approximately




7 percent) have a half-life of less than 0.1 days.  Therefore, in




streams and rivers, the majority of substances are expected to be




ranked as persistent unless settling loss is significant enough to




affect their ranks.




     Metals vs. Organics




     With only a few exceptions, decay loss is negligible for




organic chemicals over the travel time assumed.  Consequently, the




persistence rank of a substance, be it organic or metal, largely




depends on its sedimentation loss.
                                54

-------
     At a given site, the sedimentation loss of a substance depends



on the partition coefficient of the substance.  The greater the



partition coefficient, the greater the fraction present in



particulate form which may settle out.  Metals, because of their



high partition coefficients (Table 6), are expected to be attenuated



more through sedimentation loss than organic substances.



     Settling Loss With Regard to Geographic Location of the Site



     A geographical distribution of the suspended solids concen-



tration is shown in Figure 4.  On the east and west coast, the



suspended solids concentration is low—mostly in the range of 0 to



50 mg/1; thus, the effect of sorption may be insignificant for many



substances (see Sections 3.2 and 3.3).  Many states in the Mountain



Region and quite a few states in the Central Region have much higher



suspended solid concentrations (200 mg/1 to above 500 mg/1).  In



these states, the effect of sorption would be important.  On the



other hand, it is likely that suspended solids in these regions are



mostly inorganic.  If the hazardous substance of concern is organic,



then, despite the high suspended solids concentration, the low



organic content of the suspended solids may cause sorption to be



unimportant (see equation (9)).



     For most of the organic chemicals, because of the negligible



decay loss expected over the travel times considered, the value of



C/C  is estimated using equation (18):
   o
                                55

-------
                              TABLE 6

    COMPARISON OF PARTITION COEFFICIENT FOR SEVERAL SUBSTANCES
         USED TO SCORE TOXICITY/PERSISTENCE IN THE SURFACE
            WATER ROUTE OF PROPOSED AND FINAL NPL SITES
   Substance Name
Site Frequency
Log K
Metals

  Lead
  Trichloromethane (chloroform)
  Chromium
  Arsenic
  Cadmium
  Mercury
  Zinc
  Copper
  Nickel
      143
       80
       67
       55
       44
       31
       18
       13
        5
  5.0
  1.0
  4-6.5
3.7-5.7
3.6-6.6
3.4-6.5
4.2-6.1
4.0-6.0
4.1-5.7
Organics
Tetrachlorome thane (carbon
Pentachlorophenol
Benzene
Trichloroethylene (TCE)
Lindane
Phenol
Benzo-a-pyrene
Chlordane
tetra chloride)







23
31
13
18
10
8
11
9
1.8
4.0
1.6
1.4-2.0
2.0
0.5
4.0
2.0
^Number of sites at which the substance is reported present
 according to the NPL technical data base as of November 2, 1986.
bOrganics:  Calculated by means of equation (9) using the KQW
            value from Appendix C and assuming foc to be 0.25
            (which refers to suspended solids with high organic
            content).  Thus,  the calculated partition coefficients
            represent the high values of those may be expected in
            the natural environment.
   Metals:  Taken from Table 5; that is, the estimated Kp values
            over a range of suspended solids concentration from 1
            500 mg/1.
                            to
                                  56

-------



ea-
se—
§ 49-
o
t 47
< 42
CO
0 35-
o:
UJ
1 28 —
2 21-
14 —
7 —
0









01




























Mean-947
Number of stations-328
Standard deviation-6101















^
^
|
1
^





^^Bti^^-^^
— 21
— 19
- 17
-15
13

- II


- 6
- 4
- 2
0
                                                    o

                                                    UJ
     1  2  5  10 20 50 100200500 1
2 5  10 20  50 100 200 500
    thousands
   MEAN CONCENTRATION OF SUSPENDED SEDIMENT, IN MILLIGRAMS PER LITER
                                                                 EXPLANATION
                                                             Concentration of suspended
                                                            sediment, in milligrams per liter
                                                                O
                                                                     0-50


                                                                     51-200

                                                                     201-500


                                                                     501-2000

                                                                     2000-84,900
                                       Stations monitoring
                                       flow from the
                                       Great Lakes
                                                                     Water Resources
                                                                     Region boundary

                                                                     Accounting Unit
                                                                     boundary
Source- Britton et at (1983).                       o   200 400  eoo KILOMETERS
                                     FIGURE 4
MEAN CONCENTRATION OF SUSPENDED SEDIMENT AT NASQAN STATIONS DURING
     1976 WATER YEAR. MAP AT BOTTOM IS CODED TO SHOW MEAN DATA FOR
          STATIONS REPRESENTING FLOW FROM THE ACCOUNTING UNIT.
                                        57

-------
                                     ~8 —

                          C_ _ 1 + ae   U

                          C  ~ 1 + a
                           o



where  ct = Kp.(SSo)




The value of -gp represents the expected change of suspended solids



concentration over  the target distance limit (see equation (14)).



     In the limiting case where the value of a is much smaller than 1



(i.e.,  the particulate fraction is much less than 1, indicating that the



majority of the substance is present in a dissolved state), the value of



C/C  approaches 1,  and little settling loss is expected.  Thus, the



suspended solids concentration itself may dictate the persistence of



some substances regardless of the change of the suspended solids



concentration between the two locations of interest.  At a suspended



solids  concentration of 20 mg/1 (typical of eastern regions), organic


                                                   3 7
substances with partition coefficients less than 10 *  will be



persistent.  At a suspended solids concentration of 500 mg/1, fewer



substances will be  ranked as persistent (i.e., only substances with


                                   2 3
partition coefficients less than 10 ' ).  In the limiting case where



the value of a approaches 1 the persistence ranking of substances



depends on settling loss.



     Moreover, the  suspended solids concentration at a given site and



the detection limit of suspended solids automatically limit the maximum



quantifiable percent removal of suspended solids at that site (or the



lowest persistence  rank possible for a substance according to its



sedimentation loss).  This can be seen by assuming that the detection



                                  58

-------
limit for suspended solids is about 4 mg/1 (U.S. EPA, 1979).  If we

are interested in examining a site with a suspended solids

concentration of 20 mg/1, the maximum sorption loss detectable would

be 16 mg/1, or 80 percent.  At this hypothetical site, no substance

would be ranked as being either "non per sis tent" or low persistent"

as a result of settling loss.  Similarly, at a site with a higher

suspended solids concentration of 500 mg/1, the maximum detectable

sorption loss is about 99 percent, and using the methodology

outlined in Section 4.2.1, no substance would be ranked as

"non per sis tent" on the basis of settling loss.

     4.2.2  Lakes and Reservoirs

     4.2.2.1  The Ranking Method.  The details of the proposed

ranking method to be used for substances in lakes and reservoirs are

shown in Figure 5 .  Persistence ranking of substances in lakes and

reservoirs is based on the ratio between the expected concentration

at the target distance limit (C) and the inflow concentration (C ):

            Rank                           Criterion
        Persistent                      0.5 <
        Moderate                        0.1 < C/C± < 0.5
        Low                           0.001 < C/Ci < 0.1
        Nonpersistent                         C/C± < 0.001

     The ratio C/C. is calculated using equation (20).  Parameters

needed for the calculation are decay rate, settling loss rate,

dissolved (or particulate) fraction and hydraulic retention time.

Decay rate (Y) is calculated using the estimated substance half-life

(t. *«); illustrations of half-lives are presented in Appendix C:

                                 59

-------
                      Lakes/Reservoirs

                       All Substances
                 Calculate C/Cj using Eq. (24)
                  Persistant; if C/C j> 0.5

                  Moderate; if 0.5> C/C j> 0.01

                  Low; if 0.01 > C/C j> 0.001
                  Non-persistent; if 0.001 > C/C j
          Parameters:
         • Hydraulic retention time
         • Suspended solids concentration
         • Partition coefficient^
         • Decay rate 2
         • Organic carbon fraction of the suspended solids
1 For organics, calculated as 0.41 x f oc x K^ ; 1^, is available in Appendix D.
 For metals, calculated using equations in Table 4 and the suspended
 solids concentration.
2 Calculated as 0.693/half-life; illustrations of half-lives are available from
  Appendix C.
                         FIGURES
   PERSISTENCE RANKING METHOD FOR SUBSTANCES
       IN LAKES AND RESERVOIRS - ALTERNATIVE I
                          60

-------
                              Y = 0.693                          (30)
                                  tl/2
The settling loss rate can be estimated by means of equation (25) If

the concentrations of suspended solids are available.  The estimation

of dissolved fraction is described in Section 2.3.  Measurements

required include suspended solids concentrations in the inflow and

in the lake or reservoir (or outflow).  If the substance of interest

is an organic substance, the measurement of the organic fraction of

the suspended solids is also required.  Hydraulic retention time (T)

is calculated as follows:

                              T = I                              (31)

where Q is the flow rate and V is the volume of water between the

inflow location and the target distance limit.  During stratification

periods, the volume is further restricted to the portion which lies

above the thermocline.  Assuming this volume of water can be

estimated from the morphological information of the lake or

reservoir, flow rate is the parameter that requires measurement.

The total number of measurements is, therefore, four:  the suspended

solids concentrations in the inflow and in the body of the lake or

reservoir, the organic carbon fraction of the suspended solids, and

the inflow rate.
                                  61

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     4.2.2.2  Sensitivity Analysis




     Decay Loss




     The time a substance spends over the target distance limit is




generally much longer in lakes and reservoirs than in streams and




rivers.  Therefore, the longer reaction time available in lakes and




reservoirs enables decay processes to become more significant in




affecting the fate of substances.  Assuming that the reaction time is




on the order of days to years, biodegradation and volatilization can




become significant decay processes in addition to hydrolysis and




photolysis (Appendix B).




     Settling Loss




     When a stream enters a lake or reservoir, the flow velocity




begins to decline and the suspended solids will begin to be deposited.




Thus, lakes and reservoirs may be considered as sediment traps.




     Based on data collected from Tennessee Valley Authority




reservoirs, Churchill (Vanoni, 1975) relates the percentage of




incoming sediment passing through a reservoir to the sedimentation




index (SI) of the reservoir (Figure 6).   Sedimentation index is




defined as the hydraulic retention time  (in seconds) divided by the




mean flow velocity (in feet per second).  The mean flow velocity is




calculated by dividing the flow rate (Q) by the average cross-




sectional area (A).  Thus, SI is expressed as:






                            81 = Q7A
                                  62

-------
           100

            60

            40


            20

            10
Percentage of  4
incoming silt
passing
through
reservoir
             1

            0.6
            0.4

            0.2
            0.1
              10*
                                           I  I I I     I    I   I
                                         Curve for fine silt discharged
                                         from an upstream reservoir
                   J	I   I  I I	I	I	L_LJ	I	I	1_LJ	I    I   I  I  I    I     III
  105             106             107             108

Sedimentation index of reservoir = period of retention/mean velocity
10s
              Source: Vanoi, 1975.
                                          FIGURE 6
                        CHURCHILL'S TRAP EFFICIENCY CURVE
                                              63

-------
where A is the area.   Expressing area as the ratio of volume to



length of the reservoir, equation (32) may be written as:







                            31 •  
-------
The importance of decay reactions depends on the travel time between

two points.  However, the time a substance spends over the target

distance limit is distinctively different for streams and rivers than

for lakes and reservoirs.  In streams and rivers, the three-mile

travel time is expected to be much less than a day; whereas, in lakes

and reservoirs, the hydraulic retention time mostly falls in the range

of days to years.  Thus, the difference in the time scales associated

with the two types of water bodies warrants different substance

classification schemes.

     For streams and rivers, the substances are classified as follows:

     Rank                C/C                        Criterion
     	                	o_                       	

Persistent      0.5   < C/CO           0.1 days   < half-life
Moderate        0.1   < C/CO < 0.5     0.033 days < half-life < 0.1 days
Low             0.001 < C/C0 < 0.1     0.01 days  < half-life < 0.033 days
Nonpersistent           C/CO < 0.001                half-life <0.01 days

For lakes/reservoirs, the substances are classified as follows:

     Rank               C/C                         Criterion

Persistent      0.5   < C/C±           5 days     < half-life
Moderate        0.1   < C/C± < 0.5     0.5 days   < half-life < 5 days
Low             0.001 < C/Ci < 0.1     0.005 days < half-life < 0.5 days
Nonpersistent           C/C± < 0.001                half-life < 0.005 days

     In both cases, instead of using C/C  and C/C. as the criteria

as in Alternative I, the explicit criterion used for the ranking is the

half-life of the substance.  (This is to facilitate the classification

process.  Illustrations of the expected half-lives of substances are

listed in Appendices B and C.)  These half-life criteria have been

determined based on the corresponding C/C  or C/C. value shown next

to them using the methodology described below.

                                  65

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     In the case of streams and rivers, C/C  is calculated using the
following equation:
                                                                 (34)
which is essentially equation (17) with the dissolved fraction (fj)




equal to 1.  The value of — used for calculation is 0.1 days.




With each value of C/C , equation (34) is used to solve for   and




half-life is calculated as ln2/Y.




     In the case of lakes and reservoirs, C/C. is calculated using
the following equation:
                                    VT
                                                                 (35)
which is essentially equation  (24) with the dissolved fraction (f, )




equal to 1 and  the particulate fraction (fj) equal to 0.  The value




of T is assumed to be one week (7 days).  With each specified value




of C/C. , equation  (35) is used to solve for Y and half-life is




calculated as ln2/Y.




     Based on half-life values, rating tables may be prepared for




each type of water body with substances arranged according to their




ranks.  Table 7 is an e ample of such a table indicating the ranks




of substances for streams and rivers using half-life values from




Appendix B.  Appendix C contains  illustrations  of half-lives for




substances in lakes and reservoirs.   Half-lives  for  all  substances,




including those in Appendices B or C, need to be  calculated using



the methodology presented in Appendix G.





                                 66

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                                                               TABLE 7

                  CLASSIFICATION OF HAZARDOUS  SUBSTANCES  BY THEIR HALF-LIVES--STREAMS/RIVERS  I*
              Rank:  Nonoerslstent (i.e..  half-life 5  0.01 day)
              Acetyl chloride
              Benzothrlchlorlde
              Dlmethylcarbamoyl chloride
              Methyl Isocyanate
                                    Benzal chloride
                                    Bls(chloromethyl) ether
                                    Malelc anhydride
                                    Phthalic anhydride
              Rank:  Low (I.e.. 0.033 day < half-life  s  0.01 day)

              1,2-Dlphenylhydrazlne
Benzene sulfonyl chloride
Chloromethyl methyl  ether
Methyl chlorocarbonate
Toluene dllsocyanate
ON
Rank:   Moderate  (I.e..  0.033 dav-< half-life < 0.1 day)

3,3'-Dlchlorobenzldine               Dimethyl sulfate
                                                                                         Phenol
              Rank:  Persistent (I.e.. 0.1 day < half-life)
              Acenaphthylene
              Acetonltrlle
              Acroleln
              Acrylonitrile
              Allyl Alcohol
              Anthracene
              Asbestos
              Benzene
              Benzidlne
              Benzo(b)fluoranthene
              Benzyl chloride
              BIs-2-chloromethoxymethane
              Bromopropyl phenyl ether (4-)
                                    Acetaldehyde
                                    Acetophenone
                                    Acrylamlde
                                    Aldrln
                                    Ammonium Plcrate
                                    Arsenic
                                    Benzacrldlne (3,4-)
                                    Benzene, 1,3.5-trinltro
                                    Benzo(a)anthracene
                                    Benzoqulnone (p-)
                                    Bloxlrane (2,2'-)
                                    Bromoacetone
                                    Bruclne
Acetone
Acetylamlnofluorene  (2-)
Acrylic acid
Aldlcarb
Aniline
Arsenic III oxide
Benzanthracene (1,2-)
Benzenethlol
Benzo(a)pyrene
Benzotrichlorlde
Bis (2-chloroisopropyl) ether
Bromemethane
Butanol (n-)
               *Assuming a travel distance of 3 miles in 0.1  days.

-------
                                                        TABLE  7  (Continued)
              Rank:	Persistent  (I.e..  0.1  < half-Life')  (Continued)
00
Butanone (2-)
Chlorambucil
Chloro-2,3-epoxypropane (1-)
ChloroacetaLdehyde
Chloroethene
ChlorophenoX (o-)
Chromium
Cresols
Cyclohexane
Cyclophosphamide
DDD
Di-n-octylphthalate
Dibenz(a.h)anthracene
Oibutylphthalate
Dichlorobenzene (1,4-)
Dichloroethane (1.2-)
Dichloroethylene (trans) (1,2-)
Dichlorophenol (2,6-)
Dieldrin

Diethylene dioxide (1,4-)
Diisopropyl fluorophosphate
Dlmethylamine
Dlmethylfuran
DimethyIphenol (2,4-)
Dinitrotoluene (2,4-)
Dloxane (1,4-)
Endosulfan
Ethyl acrylate
Ethyl methacrylate
Ethylene dibromide
Ethylenebis(dithiocarbamic acid)
Formaldehyde
Furfural
Hexachlorobenzene
Cadmium
Chlordane
Chloro-m-cresol (4-)
Chloroaniline (p-)
Chloroethyl vinyl ether (2-)
Chlorophenyl thiourea (l-o-)
Chrysene
Crotonaldehyde
Cyclohexanone
D (2,4-)
DDT
Di-n-propylnitrosamine
Dibenzopyrene (1,2,7,8-)
Dichloro-2-butene (1,4-)
Dichlorodifluoromethane
Dichloroethene
Dlchloromethane
Dichloropropane (1,2-)
Diepoxybutene (1,2,3,4-)

Diethyl phthalate
Dimethoate
Dimethylbenz[a]anthracene (7,12-)
DimethyInitrosamine
Dimethyl phthalate
Dinitrotoluene (2,6-)
Dipropylamine
Endrin
Ethyl carbamate
Ethyl methanesulfonate
Ethylene oxide
Fluoranthene
Formic acid
Glycldylaldehyde
Hexachlorobutadiene
Carbon tetrachlorlde
Chlomaphaz ine
Chloro-o-toluldlne (4-)
Chlorobenzene
Chloromethane
Chloropropionitrile (3-)
Copper
Curoene
Cyclohexyl-4,6-dinitrophenol (2-)
D salts and esters (2,4-)
Daunomyc in
Diallate
Dibromo-3-chloropropane (1,2-)
Dichlorobenzene (1,2-)
Dichloroethane (1,1-)
Dichloroethylene (cis) (1,2-)
Dichlorophenol (2,4-)
Dichloropropane (1,3-)
Diethyl-o-pyrazlnyl-
  phosphorothioate (0.0)
Diethylstllbestrol
Dimethoxybenzidine (3,3-)
Dimethylbenzidine (3,3-)
Dimethylphenethylamine (a,or-)
Dinitro-o-cresol (4,6-)
Dinoseb
Disulfoton
Epichlorohydrin
Ethyl ether
Ethyl-4,4'-dichlorobenzllate
Ethylenimine
Fluoroace tamlde
Fur an
Ueptachlor
Hexachlorocyclohexane  (a-)

-------
                                        TABLE 7  (Continued)
Rank:  Persistence (i.e.. 0.1 days < half-life) (Continued)
Hezachlorocyclopentadiene

Hydraz ine
Isosafrole
Lindane
Mercury
Hethapyrilene
Methyl ethyl ketone
Methyl methacrylate
Methyllacetonitrile (2-)
Methylene chloride
Mltomycln C
Naphthylamine (1-)
Nickel
Nitro-o-toluidlne (5-)
Nltrophenol (4-)
Nitroso-n-ethylurea (n-)
Nitrosodiethanolamine (n-)
Nltrosoplperidine (n-)
Octachlorocamphene
Paraldehyde
Pentachloroethane
Pentadlene (1,3-)
Phenyl-thiourea  (n-)
Plcollne (2-)
Propane nltrlle
Pyrene
Reserplne
Safrole
Silver
Strychnine
Hexachloroethane

Indeno(1,2,3-cd)pyrene
Kepone
Malononitrile
Methanethlol
Methorny1
Methyl hydrazine
Methyl parathion
Methylcholanthrene (3-)
Methylenebls (2-chloroanlllne) (4,4
Naphthalene
Naphthylamine (2-)
Nickel carbonyl
Nitrobenzene
Nitropropane (2-)
Nitroso-n-methyl urethane (n-)
Nitrosodiethylamlne (n-)
Nitrosopyrrolidlne (n-)
Osmium tetroxide
Parathion
Pentachloronitrobenzene
Phenacetin
Phorate
Pronamide
Propane sultone (1,3-)
Pyrldinamlne (4-)
Resorcinol
Selenium
Silvex
T (2.4,5-)
   Hexachlorohexahydro-exo,
     exo-d ime thanonaphthalene
   Isobutanol
   Lead
   Melphalan
   Methanol
   Methyl aziridine
   Methyl iodide
   Methyl-2-pentanone (4-)
   Methylene bromide
-) Methylthiouracil
   Naphthalenedione (1,4-)
   Naphthylthiourea (a-)
   Nicotine
   Nitroglycerin
   Nitroso-di-n-butylamine (n-)
   Nitroso-n-methylurea (n-)
   Nltrosomethylvinylamine (n-)
   0-Nitrotoluene
   PCB-1254
   Pentachlorobenzene
   Pentachlorophenol
   Phenylmercurie acetate
   Phosgene
   Propanamlne (1-)
   Propyn-1-ol (2-)
   Pyridine
   Saccharin
   Selenium dioxide
   Streptozotocin
   Tetrachlorobenzene (1,2,4,5-)

-------
                                       TABLE  7  (Concluded)


Rank:  Persistence (I.e.. 0.1 days < half-life) (Concluded)

Tetrachloroethane (1,1,1,2-)         Tetrachloroethane (1,1,2,2-)            Tetrachloroethene
Tetrachloroethylene                  Tetrachloromethane                     Tetrachlorophenol  (2,3,4,6-)
Tetrahydrofuran                      Tetranltromethane                      Thlfanox
Toluene                              Toluenediamine                         Toluldlne hydrochlorlde (o-)
Toxaphene                            Trlchloroacetaldehyde                  Trlchloroethane  (1,1,1-)
Trlchloroethane (1,1,2-)             Trlchloroethene                        Trichloroethylene
Trlchloromethyl mercaptan            Trichloromonofluoromethane             Trichlorophenol  (2,4,5-)
Trichlorophenol (2,4,6-)             Trls(2,3-dlbromopropyl)phosphate        Uracll.5-[bis
                                                                              (2-chloromethyl)amlno]
Warfarin                             Xylene                                 Zinc

-------
5.0  DISCUSSION AND CONCLUSIONS




     The current HRS considers biodegradability of hazardous




substances as the sole mechanism affecting their persistence in the




environment.  Biodegradation, however, is only one of several




physical, biological and chemical processes that play a role in the




persistence of substances in the environment and, in some instances,




may be insignificant relative to other processes.  This study has




examined alternatives for incorporating in the HRS the consideration




of five additional processes:  hydrolysis, photolysis, volatilization,




free-radical oxidation, and sorption.  Of these, sorption has been




identified as the process having the greatest effect in streams and




rivers over the distances currently considered in the HRS.  Dilution




is not considered in this study but may, under some circumstances,




overshadow these processes and should be examined independently.




5.1  Comparison of the Two Alternative Persistence Ranking Methods




     The two alternative persistence ranking methods described in




Section 4 differ in the number of environmental attenuation processes




considered.  Alternative I considers the effect of sorption and the




decay processes of biodegradation, hydrolysis, photolysis,




free-radical oxidation, and volatilization.  Alternative II considers




the effect of only the five latter decay processes.  A comparison of




the two alternatives are discussed below.




     If sorption is not considered, substances may be ranked




according to their estimated decay half-lives.  Therefore,
                                  71

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Alternative II would be more easily implemented since it requires




only look-up tables that can be prepared from estimated half-lives.




     However, if sorption followed by settling is truly a loss




process, the omission of the sorption process may significantly




alter the accuracy of an estimate of actual environmental attenuation




potentials among substances.  This is especially true for streams




and rivers where sorption, followed by settling, may potentially be




the dominant loss mechanism for a majority of substances over the




target  distance limits considered.  In lakes and reservoirs these




substances may be less persistent than in streams and rivers because




of the  longer reaction time in lakes and reservoirs and because




lakes and reservoirs tend to be good sediment traps.




     Metals, because of their high partition coefficients, are more




likely  to be affected by sorption than organics.  If sorption is not




included in ranking the persistence of substances, metals will




always  be considered as the most persistent group.




     Alternative I could be considered preferable based on the




assumption that the persistence of substances is solely a function




of various loss mechanisms in the surface water column.  However,




Alternative I disregards possible ecological effects caused by




contaminated sediments or other effects from the resuspension of the




contaminated sediments.  Alternative II would be a better mechanism




to consider these effects.




     Another potential disadvantage of Alternative I is that,  when




sorption is considered, site measurements are required in order to



                                 72

-------
quantify the settling loss rate between the two locations of




interest.  Parameters requiring measurement include:  suspended




solids concentrations near the point of entry and at a downstream




location, and organic carbon content of the suspended solids.




     Suspended solids concentration has been included in most water




quality monitoring programs.  For eample, the U.S. Geological




Survey routinely measures the suspended solids concentration on its




NASQAN stations (Britton et al., 1983).  Although it is unlikely




that the NASQAN stations will provide information for the variation




of suspended solids concentration within less than a three-mile




distance, the information from the two nearest NASQAN stations may




provide useful guidelines on the design of the sampling program for




determining suspended solids concentrations for use in persistence




ranking.  In addition, programmatic decisions can be made which




further simplify or even dictate the extent of the sampling




program.  For example, EPA could decide that the low-flow period is




the critical period (because of its lower dilution capacity), and




that sampling should be conducted during this period.




5.2  Comparison With the Current HRS Persistence Ranking Method




     The two alternatives discussed in Section 4, in addition to




being more theoretically sound than the current method in the HRS,




offer the advantages of consistency and traceability in comparison




with the current persistence ranking method.  In both alternatives,




the persistence rank of a substance is based on the expected change
                                  73

-------
of the substance concentration over the target distance limit




currently specified in the HRS.




     Different effects are expected on the current persistence ranks




of substances if either of the two proposed alternatives are used.




The application of Alternative I could be expected to lower the




ranking of a substance (e.g., from persistence to moderate) if the




sedimentation loss is significant at the site or if biodegradation




is not the dominant decay process.  The application of Alternative II




could be expected to lower the ranking of a substance if biodegrad-




ation is not the dominant decay process.




     Even without sorption and subsequent sedimentation loss, the




consideration of hydrolysis, photolysis, free-radical oxidation, and




volatilization, in addition to biodegradation, may affect the




current persistence ranking of substances.  The ranks of some




substances may be lowered, compared with their current HRS




persistence ranks, because their half-lives are very short as a




result of decay processes other than biodegradation.  For example,




bis(chloromethyl)ether, currently ranked as "persistent," would be




ranked as "nonpersistent" in streams and rivers because of its short




half-life (less than 0.01 days) due to rapid hydrolysis.




     Other substances, however, may have their rank values increased




(e.g.,  from low to persistent).  Ranks could be increased because




the qualitative basis in the current method may not be consistent




with the quantitative evaluation of half-life in the proposed
                                  74

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method.  For example, a substance currently ranked low may actually




have a longer biological half-life than a substance currently ranked




moderate.  Additionally, the proposed ranking methods consider the




effect of travel time or residence time (i.e., the available time




for reaction) in the environment whereas the current method does




not.  As a result, the proposed ranking methods are not likely to




produce the same grouping as the existing HRS method.




     In fact, more substances would likely be classified as




persistent with the application of either of the proposed




alternatives than under the present system.  Of the more than 250




hazardous substances listed in Appendix B, more than 90 percent are




ranked as persistent in streams and rivers under Alternative II.




     This result might initially appear illogical because the more




decay processes considered, the less persistent a chemical might be




expected to be.  However, it should be noted that the current




persistence ranking method differs from the proposed alternatives




not only in the number of decay processes considered but also in the




manner in which the "break" points of different ranks are selected.




The current method ranks substances according to a qualitative




relative estimate of biodegradability without assessing the




significance of a particular rate of biodegradation in a given




environment.  Because of the relatively short travel time expected




over the target distance limit in streams and rivers (0.1 days),




many chemicals which are usually considered easily biodegradable
                                  75

-------
 would be regarded as  persistent according to  the  proposed

 methodologies.   For example, acetone with a biodegradation half-life

 of five days  is currently classified as  easily biodegradable and  is

 currently ranked as "nonpersistent." However, it  would be classified

 as persistent in streams  and rivers according to  the  proposed

 alternatives  because  only a one percent  change in concentration is

 expected from the point of entry  to the  target distance limit.

      EPA may  consider extending the target distance limit in surface

 water in view of the  findings  from Burger  and Rushner (1986).  For

 illustrative  purposes, if the  target distance limit is extended to

 15 miles,  then substances would be ranked  as  follows according to

 Alternative II:

                          Streams  and Rivers
                    (assuming 0.5  day travel time)
     Rank

 Persistent
 Moderate
 Low
 Nonpersistent
        C/C
        	o_
0.5   < c/c0
o.i   < c/c0 < 0.5
o.ooi < C/GO < o.i
             < o.ooi
            Criterion

0.5 days  < half-life
0.1 days  < half-life < 0.5 days
0.05 days < half-life < 0.1 days
            half-life < 0.05 days
                        Lakes and Reservoirs
                   (assuming 30 days travel time)
     Rank

Persistent
Moderate
Low
Nonpersistent
         c/c
           Criterion
0.5   <
0.1   < C/Ci < 0.5
0.001 < C/Ci < 0.1
             < 0.001
20 days   < half-life
2 days    < half-life < 20 days
0.02 days < half-life < 2 days
            half-life < 0.02 days
                                   76

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Even under these conditions, only a small number of substances are




expected to be ranked as less than persistent in streams and rivers,




as illustrated in Table 8.




     The possibility of limiting the ranking of substances to




biodegradation processes rather than considering the other decay




processes also has been evaluated.  Thirty-two substances listed in




Appendix B have half-lives of one day or less.  The dominant decay




processes for these 32 substances are tabulated in Table 9.




     Hydrolysis is the dominant process for 16 of these substances,




including all of the substances with half-lives less than 0.01 days.




Volatilization dominates this decay of 6 other substances, and




photolysis dominates 3 other substances.  Biodegradation is the




dominant process for only 3 of the substances, illustrating the




inadequacy of this factor as the sole criterion for ranking the




persistence of substances in surface water.
                                  77

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                                                              TABLE  8

                 CLASSIFICATION OF  HAZARDOUS  SUBSTANCES BY THEIR  HALF-LIVES--STREAMS/RIVERS  II*
              Rank:  Nonperslstent (i.e.. half-life < 0.05  day)
              Acetyl chloride
              Benzothrichloride
              Dimethylcarbamoyl chloride
              Methyl chlorocarbonate
              Toluene dilsocyanate
Benzal chloride
Bis (chloromethyl) ether
Diphenylhydrazine  (1,2-)
Methyl isocyanate
Benzene sulfonyl  chloride
Chloromethyl  methyl  ether
Maleic anhydride
Phthalic anhydride
              Rank:  Low (i.e.. 0.05 day < half-life & 0.1  day)

              Dichlorobenzidine (3,3'-)            Dimethyl sulfate
                                      Phenol
00
               Rank:  Moderate (i.e. .  0.1 day < half-life <  0.5  day)
               Benidine
               Heptachlor
Benzyl Chloride
Hexachlorocyclopentadiene
                                                                                         Dipropylamlne
               Rank:   Persistent (I.e.. 0.5 day < half-life)
               (Aminomethyl)-3-lsoxazolol (5-)
               Acetone
               Acetylaminofluorene (2-)
               Acrylic  acid
               Aldicarb
               Aniline
               Arsenic (lll)oxide
               Benzanthracene (1,2-)
               Benzenethiol
               Benzo(b)fluoranthene
               Benzyl chloride
Acenaphthylene
Acetonitrile
Acrolein
Acrylonitrile
Allyl Alcohol
Anthracene
Asbestos
Benzene
Benzo(a)anthracene
Benzoquinone (p-)
Bioxirane (2,2-)
Acetaldehyde
Acetophenone
Acrylamide
Aldrin
Ammonium Picrate
Arsenic
Benzacridine (3,4-)
Benzene, 1.3,5-trinitro
Benzo(a)pyrene
Benzotrichlorlde
Bis  (2-chloroisopropyl) ether
               *Assuming a travel distance of 15 miles in 0.5 days.

-------
                                         TABLE  8  (Continued)
Rank:  Persistent (I.e.. 0.5 day < half-life) (Continued)
Sis-2-chloromethoxymethane
Bromopropyl phenyl ether (4-)
Butanone (2-)
Chlorambucil
Chloro-2,3-epoxypropane (1-)
Chloroacetaldehyde
Chloroethene
Chlorophenol (o-)
Chromium
Cresols
Cyclohexane
Cyclophosphamide
ODD
Di-n-octylphthalate
Dibenz(a,h)anthracene
Dibutyl phthalate
Dichlorobenzene (1,4-)
Dichloroethane (1,2-)
Dtchloroethylene (trans) (1,2-)
Dichlorophenol (2,6-)
Dieldrin

Diethylene dioxide (1,4-)
Diisopropyl fluorophosphate
Dimethylamine
DimethyInltrosamine
Dimethyl phthalate
Dinitrotoluene (2,6-)
Diphenylhydraz ine (1,2-)
Endrln
Ethyl carbamate
Ethyl methanesulfonate
Ethylene oxide
Fluoranthene
Bromoacetone
Bruc ine
Cadmium
Chlordane
Chloro-m-cresol (4-)
Chloroanlline (p-)
Chloroethyl vinyl ether (2-)
Chlorophenyl thiourea (l-o-)
Chrysene
Crotonaldehyde
Cyc1ohexanone
D (2,4-)
DDT
Di-n-propylnitrosamine
D ibenzopyrene (1,2,7,8-)
Dichloro-2-butene (1,4-)
Dichlorodifluoromethane
Dichloroethene
Dlchloromethane
Dichloropropane (1,2-)
Dlepoxybutene (1,2,3,4-)

Diethylphthalate
Dimethoate
DimethyIbenz[a]anthracene (7,12-)
Dimethylphenethylamine (0,0-)
Dinitro-o-cresol (4,6-)
Dinoseb
Disulfoton
Epichlorohydrin
Ethyl ether
Ethyl-4,4'-dichlorobenzilate
Ethylenimine
Fluoroacetamide
Bromemethane
Butanol (n-)
Carbon tetrachlorlde
Chlornaphaz ine
Chloro-o-toluidine (4-)
Chlorobenzene
Chloromethane
Chloropropionitrile (3-)
Copper
Cumene
Cyclohexyl-4,6-dinitrophenol (2-)
D salts and esters (2,4-)
Daunomyc in
Diallate
Dibromo-3-chloropropane (1,2-)
Dichlorobenzene (1,2-)
Dichloroethane (1,1-)
Dichloroethylene (cis) (1,2-)
Dichlorophenol (2,4-)
Dichloropropane (1,3-)
Diethyl-o-pyrazinyl-
  phosphorothioate (0.0)
Diethylstilbestrol
Dimethoxybenzidine (3,3-)
Dimethylbenzidine (3,3-)
Dimethylphenol (2,4-)
Dinitrotoluene (2,4-)
Dioxane (1.4-)
Endosulfan
Ethyl acrylate
Ethyl methacrylate
Ethylene dibromide
Ethylenebis(dithiocarbamic acid)
Formaldehyde

-------
                                                         TABLE 8  (Continued)
                Rank:  Persistence (i.e., 0.5 days < half-life) (Continued)
GO
O
Formic acid
Glycidylaldehyde
Hexachlorocyclohexane (a-)

Hydrazine
Isosafrole
Lindane
Mercury
Methapyrilene
Methyl chlorocarbonate
Methyl iodide
Methyl-2-pentanone (4-)
Methylene bromide

Methylthiouracil
Naphthalenedione (1,4-)
Naphthylthiourea (a-)
Nicotine
Nitroglycerin
Nltroso-dl-n-butylamine (n-)
Nitroso-n-methylurea (n-)
Nitrosomethylvinylamine (n-)
0-Nitrotoluene
PCB-1254
Pentachlorobenzene
Pentachlorophenol
Phenylmercuric acetate
Phosgene
Propanamine (1-)
Propyn-1-ol (2-)
Pyridlne
Saccharin
Selenium dioxide
Streptozotocln
Fur an
Hexachlorobenzene
Hexachloroethane

Indeno(l,2,3-cd)pyrene
Kepone
Malononitrile
Methanethiol
Methorny1
Methyl ethyl ketone
Methyl methacrylate
Methyllacetonitrile  (2-)
Methylene chloride

Mitomycin C
Naphthylamine (1-)
Nickel
Nitro-o-toluidine (5-)
Nitrophenol (4-)
Nitroso-n-ethylurea  (n-)
Nitrosodiethanolamlne (n-)
Nitrosopiperidine (n-)
Octachlorocamphene
Paraldehyde
Pentachloroe thane
Pentadlene (1,3-)
Phenyl-thiourea (n-)
Picoline (2-)
Propanenitrile
Pyrene
Reserpine
Safrole
Silver
Strychnine
Furfural
Hexachlorobutadiene
Hexachlorohexahydro-exo,
  exo-dimethanonaphthalene
Isobutanol
Lead
Melphalan
Methanol
Methyl aziridine
Methyl hydrazlne
Methyl parathion
Methylcholanthrene (3-)
Methylenebis
  (2-chloroanlllne) (4.4'-)
Naphthalene
Naphthylamine (2-)
Nickel carbonyl
Nitrobenzene
Nitropropane (2-)
Nltroso-n-methyl urethane (n-)
Nltrosodiethylamine (n-)
Nitrosopyrrolidine (n-)
Osmium tetroxide
Parathion
Pentachloronltrobenzene
Phenacetln
Phorate
Pronamlde
Propane sultone (1,3-)
Pyridinamine (4-)
Resorcinol
Selenium
Silvex
T (2,4.5-)

-------
                                                       TABLE  8 (Concluded)
              Rank:  Persistence (i.e.. 0.5 days < half-life) (Concluded)
oo
Tecrachlorobenzene (1,2,4,5-)
Tetrachloroethene
Tetrachlorophenol (2,3,4,6-)
Thlfanox
Toluldlne hydrochlorlde (o-)
Trlchloroethane (1,1,1-)
Tr ichloroethy1ene
Trichlorophenol (2,4,5-)
Uracll,5[bls(2-chloromethyl)amlno
Zinc
Tetrachloroethane (1,1,1,2-)
Tetrachloroethylene
Tetrahydrofuran
Toluene
Toxaphene
Trlchloroethane (1,1,2-)
Trlchloromethyl mercaptan
Trichlorophenol (2,4,6-)
Warfarin
Tetrachloroethane (1,1,2,2-)
Tetrachlorome thane
Tetranltromethane
Toluenedlamlne
Trlchloroacetaldehyde
Trichloroethene
Trlchloromonofluoromethane
Trls(2,3-dlbroitopropyl)phosphate
Xylene

-------
OO
                                                         TABLE  9


              THE DOMINANT  PROCESS FOR SUBSTANCES WITH  HALF-LIFE EQUAL TO OR  LESS  THAN 1 DAY



                    	Dominant  Process	
                                                                                                             Hydrolysis and
   Half-Life,                                                             Free-Radical    Volatilization and    Free-Radical
  t. ,.,  (days)       Biodegradation  Hydrolysis  Photolysis  Volatilization    Oxidation        Biodegradatlon       Oxidation

        < 0.01                         12


0.01 <  ti/2 < 0.1         1             1           1                           1


  0.1 < t!/2 < 1          2             3           2            6              1                   1                1


Note:   Numbers shown  in the table represent the total number of substances belonging to the identified category.
       0.01 day = 15  minutes
       0.1  day = 2.4 hours

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6.0  BIBLIOGRAPHY

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-------
Environ Corporation, 1984.  "Exposure Profiles Prepared in Support of
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Fiksel, J. and M. Segal, 1982.  "An Approach to Prioritization of
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French, J. G. et al. (1984).  A System for Prevention, Assessment, and
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Garde, R. J. and K. G. Ranga Raja, 1977.  Mechanics of Sediment
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Garten, C. T. and J. R. Trabalka, 1983.  "Evaluation of Models for
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Geyer, H., G. Politzki, and D. Freitag, 1984.  "Prediction of
Ecotoxicological Behavior of Chemicals:  Relationship Between
n-Octanol/Water Partition Coefficient and Bioaccumulation of Organic
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Hunter, K. A. and P. S. Liss (1979).  "The Surface Charge of Suspended
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                                  85

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Hunter, K. A. (1980).  "Mlcroelectrophoretic Properties of Natural
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Koch,  R., 1984.   "A Theoretical-Methodological Approach Towards the
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Kurbatov, M. H., G. B. Wood, and J. D. Kurbatov, 1981.  "Isothermal
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Luecker, E. B. (1982).  "Navy Assessment and Control of Installation
Pollutant (NACIP) Confirmation Study Ranking Model," Proceedings of
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                                  87

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                                 88

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                                 89

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                             APPENDIX A




     REVIEW OF PERSISTENCE FACTORS IN OTHER SITE RANKING SYSTEMS




     This appendix reviews the persistence factors that have been




incorporated in 11 other systems used to rank the threat posed by




hazardous waste sites.  The review focuses on how the persistence




factors are used in the various systems and how persistence is




defined and evaluated in the various ranking systems.  If more than




one transport pathway is considered, the review focuses on the




surface water pathway.  Important similarities and differences




between these factors and the HRS persistence factor are identified.




     The 11 ranking systems reviewed are:




     •  JRB Methodology




     •  HARM




     •  HARM II




     •  CSR




     •  ADL




     •  S.P.A.C.E. for Health




     •  Dames and Moore Methodology




     •  PERCO




     •  SAS




     •  Action Alert System




     •  RAPS
                                 91

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A.I  JRB Methodology

     The JRB methodology was developed by JRB Associates, Inc. to

evaluate the relative potential environmental impact among land based

hazardous waste disposal sites (JRB, 1980).  It considers four

generic areas:  receptors, pathways, waste characteristics, and waste

management practices.

     Waste characteristics are evaluated based on nine factors,

including a persistence factor.  In considering persistence, each

waste is assigned an integer value of 0, 1, 2, or 3 depending on the

biodegradability of the waste:

           Characteristics                  Rating Scale Levels

     Easily biodegradable compounds                  0

     Straight chain hydrocarbon                      1

     Substituted and other ring                      2
     compounds

     Metals, polycyclic compounds                    3
     and halogenated hydrocarbons

A look-up table was prepared for more than one hundred chemicals.

     Both the persistence rating criteria and the look-up tables from

the JRB methodology are adopted in the current HRS.

A.2  HARM

     The Hazard Assessment Rating Methodology (HARM) is used by the

U.S. Air Force to rank hazardous substance sites for priority

attention for follow-on site investigations and confirmation

activities under Phase II of the Air Force's Installation
                                 92

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Restoration Program  (IRP).  HARM is designed to use data developed

during the Record Search  (Phase I) portion of the IRP (Engineering-

Science, 1983).  Record Searches are essentially equivalent to EPA

Preliminary Assessments.

     The HARM  score  is developed from four subscores:  receptors,

pathways, waste characteristics, and waste management practices.  A

total risk is  estimated by  averaging and normalizing the first three

subscores.

     Waste persistence is one  of the three factors considered in

waste characteristics.  Depending on the persistence of the waste,

each waste is  assigned a  value called "persistence multiplier."

         Persistence Criteria               Persistence Multiplier

     Metals, polycyclic compounds,                     1.0
     and halogenated hydrocarbons

     Substituted and other  ring                        0.9
     compounds

     Straight  chain  hydrocarbons                       0.8

     Easily biodegradable compounds                    0.4

Despite the difference in values assigned to each rank, the criteria

used in HARM are the same as those used in the current HRS.

A. 3  HARM II

     The Hazard Assessment  Rating Methodology II (HARM II) is a

modification and extension  of  the HARM system that is intended to

permit the use of site-specific monitoring data in setting

priorities.  HARM II is used by the U.S. Air Force in Phase II of
                                  93

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the IRP program to set priorities for detailed site investigations and




possible remedial action (Barnthouse et al., 1986).




     When the measured contaminant concentration is used to assess the




health and ecological hazards of contaminants, there is no need to




evaluate persistence.  In the absence of measured concentration data,




the persistence multiplier (M ) is used with several other factors




to calculate the health hazard score and the ecological hazard score.




     The persistence multiplier used in HARM II is the same as that




defined in HARM, and therefore is based on the same criteria as is




employed in the current HRS.




A.4  CSR




     The Confirmation Study Rating (CSR) model is used by the




U.S. Navy in the Navy Assessment and Control of Installation




Pollutants (NACIP) Program to assign priorities for further study to




hazardous substance sites.   The CSR model is based on the HARM system




and the JRB model, but differs from them in several areas including




the waste characteristics scoring approach (Luecker, 1982).




Nonetheless, persistence, which is one of the 13 factors considered in




the waste characteristics section, is evaluated according to the




identical criteria as those in the JRB model.  Since persistence in




the current HRS is adopted from the JRB model, persistence in the CSR




model is evaluated in the same manner as in the current HRS.
                                  94

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A.5  ADL




     The Arthur D. Little, Inc. (ADL) system is an adaptation of the




HRS that was developed for the Chemical Manufacturers Association




(Fiksel and Segal, 1982).




     Persistence is one of the seven factors considered in evaluating




the amount of waste released from a site.  Persistence of waste is




evaluated in the same manner as in the current HRS.




A.6  S.P.A.C.E. for Health




     The System for Prevention, Assessment, and Control of Exposures




and Health Effects from hazardous sites (S.P.A.C.E. for Health) was




developed by the Centers for Disease Control (CDC) for use in public




health assessments of hazardous sites (French et al., 1984; Kay and




Tate, 1984).  The system is used to assign priorities to sites, based




on the potential of the site to endanger human health.




     Site characteristics is one of four factors used in S.P.A.C.E.




for Health for determining the site priority.  Site characteristics




include seven factors, and the persistence of the five most hazardous




substances at a site is one of the factors considered.  Persistence of




a substance is determined by using the same look-up tables that are in




the current HRS.




A.7  Dames and Moore Methodology




     The Dames and Moore Methodology was developed to evaluate waste




disposal sites with respect to their potential for ground and surface




water contamination (Dames and Moore, undated).
                                 95

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     It consists of four rating areas.  One of these rating areas is




Material Hazards Rating, which includes persistence as one of seven




rating factors.  Persistence of a hazardous substance is assigned a




rating value of 0, 1, 2, or 3, depending on the biodegradability of




the hazardous substance.  The criteria for evaluating the




biodegradability of a hazardous substance are the same as those in the




current HRS.  No look-up table is presented.




A.8  PERCO




     The Prioritization of Environmental Risks and Control Options




(PERCO) model (Arthur D. Little, Inc., 1983) was developed for the




Massachusetts Department of Environmental Quality Engineering for use




in ranking contaminated sites in terms of immediate and long-term




environmental and human health hazards.  The ranking is used to




provide a rationale for allocation of state remedial action funds.




     PERCO evaluates the potential risks posed by a site by




considering the following six migration paths:  air, ground water,




surface water, soil/direct contact, fire/explosion, and flood.




     In the surface water pathway, an attenuation score is used to




identify sites with similar characteristics.  Persistence of waste is




one of the factors considered in the attenuation score.  There is no




clear description on how persistence is ranked in the surface water




pathway; however, in scoring persistence of hazardous substances




through flood, PERCO suggests using the following criteria:
                                 96

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              Criteria                            Persistence score

     Easily biodegradable compounds                      2
     and straight chain hydrocarbons

     Substituted and other ring compounds;               3
     metals, polycyclic compounds and
     halogenated hydrocarbons

     This scoring scheme differs from the current HRS in that

persistence scores become higher for most substances:  substances

that receive a score of 0 or 1 in the current HRS will receive a

score of 2 in PERCO; substances that receive a score of 2 or 3 in

the current HRS will receive a score of 3 in PERCO.

     PERCO made the changes based on the consideration that areas

less than several miles downstream of a waste site may not

necessarily benefit from any lack of long-term persistence.

A. 9  SAS

     The Site Assessment System (Michigan, 1983) is used to assess

and prioritize release sites for further investigation and possible

remedial action.

     Persistence is one of the seven factors considered in

evaluating the chemical hazard of a substance.  Persistence is

defined as follows:

           Criteria                         Persistence Score

     Half-life in soil, air or                      5
     water < 6 months

     Half-life in soil, air or                      0
     water < 6 months
                                 97

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No tables are available on the expected half-lives for various




substances considered.




A.10  The Action Alert System




     The Action Alert System (AAS) was developed to support the




Monitoring and Data Support Division, Office of Water Regulations and




Standards (OWRS), U.S. EPA.  The purpose of the AAS is to serve as a




screening tool that separates large numbers of priority pollutants




into more manageable clusters (Fiksel and Segal, 1980).




     The underlying conceptual framework for the Action Alert System




consists of a hierarchy of data elements.  Environmental concentration




of the toxic pollutant is required to evaluate the effect and the




hazard.




     Environmental concentration is estimated using information on the




release rate of the substances and their environmental fates.  The




term "persistence" is not explicitly used.  Instead, rates are




estimated for several environmental loss processes in predicting the




environmental fate of substances.  The loss processes considered are




hydrolysis, photolysis, free-radical oxidation, and volatilization.




A. 11  RAPS




     The Remedial Action Priority System (RAPS) was developed for the




U.S. Department of Energy to more realistically assess the risks posed




by radioactive waste constituents.  RAPS considers four major pathways




for contaminant migration:  ground water, overland, surface water, and




atmosphere (Whelan et al., 1986).
                                98

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     In estimating the contaminant concentration in the surface water

pathway, RAPS uses the steady-state, vertically integrated mass

balance equation:
in which


                      f£ = 0 at y = 0 and y = B
                      dy

where  C = Dissolved in-stream contaminant concentration.
       u = Average stream flow velocity.
      Ey = Lateral or transverse dispersion coefficient.
       B = Width of stream.
       Y = Degradation/decay constant (0.693/half-life).

     There is no further elaboration on the number of processes

which are considered in estimating the degradation/decay constant.

In the case of the examples illustrated in the reference document,

arsenic is given a half-life of 8 years and Strontium-90 is given a

half -life of 28.5 years.
                                 99

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                             APPENDIX B




       ILLUSTRATIVE HALF-LIVES  OF SUBSTANCES  IN  STREAMS/RIVERS




     The half-life values presented in this appendix are based on a




limited sample of comprehensive literature review articles.   As a




result, the half-life values in the appendix may not be  the  best




available estimates.  Moreover, the values in these review articles




may not have been estimated in a manner consistent with the




methodology described in Appendix G.  As a result, these half-life




values should be used for illustrative purposes only.  Specifically,




these values were collected for preliminary assessment on the




availability of the data, and to estimate the feasibility and




sensitivity of the proposed ranking methods.
                                 101

-------
                                     TABLE  B-l

     ILLUSTRATIVE  HALF-LIVES OF SUBSTANCES IN STREAMS/RIVERS
                                        Dominant
Waste Name

Acenaphthylene
Acetaldehyde
Acetone
Acetonitrile
Acetophenone
Acetyl Chloride
Acetylaminofluorene  (2-)
Acrolein
AeryI amide
Acrylic acid
Acrylonitrile
Aldicarb
Aldrin
Allyl alcohol
Ammoniun Picrate
An iIi ne
Anthracene
Arsenic
Arsenic III oxide
Asbestos
a-naphthylthiourea
Benzacridine (3,4-)
Benzal chloride
Benzanthracene (1,2-)
Benzene
Benzenethiol
Benzene,  1,3,5-trinitro
Benzensulfonyl  Chloride
Benzidine
Benzoquinone (p-)
Benzotrichloride
Benzo(a)anthracene
Benzo(b)fluoranthene
Benzo(a)pyrene
Benzyl Chloride
Bioxirane  (2,2-)
Bis(chloromethyl)ether
Bis-2-chloroisopropyl ether
8is-2-chloromethoxymethane
Bromoacetone
Bromoform
Bromomethane
Process
H P V
*
*



*

*


*

*

*
*
*





*

*
*
*
*


*
*
*
*
*
*
*
*


*
*
Half-life
0 (days)
3.8
1.0
5.0
7.0
<13
0.00000006
>365
2.6
>»365

2.1
>365
2.8
8
<32
<47
1.3
999
999
999
>365
999
0.005
999
1.3
1.8
1.9
0.0026
* 0.262
>5
0.002
3.8
3.8
1.2
0.37
29
0.00029
3.4
>365
175
2.3
1.2
References &
Comments
4a
4
1,2,3
4
1,2.3
1,2.3
1,2,3
1,2,3
1,2,3
1.2,3
4
1,2.3
1,2,3
1,2,3
1,2,3; explosive
1,2,3
5
1,2,3
1,2,3
7
1,2,3
1,2.3
1,2,3
1,2,3
4
1,2,3
1,2,3
1,2,3
6
1,2,3
1.2,3
4a
4a
4a
1,2,3
1,2,3
1
1,2,3
1,2,3
1,2,3; poisonous gas
1,2,3
1,2,3
                                         102

-------
                             TABLE B-l  (Continued)
 Waste Name

 Bromopropyl  phenyl ether (4-)
 Brucine
 Butanol (n-)
 Butanone (2-)
 Cadmium
 Carbon tetrachloride
 Chlorambucil
 Chlordane
 Chlornaphazine
 Chloroacetaldehyde
 Chloroaniline Cp-)
 Chlorobenzene
 Chloroethene
 Chloroethyl vinyl ether (2-)
 Chloroform
 Chloromethane
 Chloromethyl methyl ether
 Chloronapthalene (B-)
 Chlorophenol (o-)
 Chloropropionitrile (3-)
 Chloro-2,3-epoxypropane (1-)
 Chloro-m-cresol (4-)
 Chloro-o-toluidine (4-)
 Chromiifn
 Chrysene
 Copper
 Cresols
 Crotonaldehyde
 Cumene
 Cyclohexane
 Cyclohexanone
 Cyclohexyl-4,6-dinitrophenol (2-
 Cyflophosphamide
 Oaunomycin
 ODD
 DDT
 D(2,4)
 D(2,4)  salts and esters
 Diallate
 Dibenzopyrene (1,2,7,8-)
Dibenz(a,h)anthracene
Dibromo-3-Chloropropane (1,2-)
Dominant
Process
B H P V 0
*

*
*

*

*

*
*
*
*
*
*
*
*
*

*
*

*

*

*
*
*
*

*


*
*


*

*
*
+
Half-life
(days)
2.0
>365
19.0
6.3
999
1.3
<365
4.2
<365
1.25
57
1.4
1.0
1.5
1.2
0.9
0.00029
2.1
>5; <37
4.1
4.9

18
999
6
999
8
12
1.4
1.1

2.2
<365
>365
2.2
7.4
999
>365
3.2
999
3.8
3.2

References &
Comments
1,2,3
1,2,3
1,2,3
1,2,3

1,2,3
1,2,3
4
1,2,3
4
1,2,3
4
1,2,3
1,2,3
4
1,2,3
1,2,3
1,2,3
1,2,3
1,2,3
1,2.3
1,2,3
1,2,3

4a

1,2,3
1,2,3
1,2,3
1,2,3
1,2,3
1,2,3
1,2,3
1,2,3
,2,3
,2,3
,2,3
,2,3
,2,3
,2,3
4a
1,2,3
                                         103

-------
                             TABLE  B-l (Continued)
                                          Dominant                +
                                          Process        Half-life        References &
 Waste Name                             B  H  P  V  0      (days)             Comments

 Dibutylphthalate                          *            >80                   1-2'3
 Dichlorobenzene (1,2-)                          *      1.5                    *
 Dichlorobenzene (1,4-)                          *      1.5                    *
 Dichlorobenzidine (3,3'-)                     *         °-06                   5
 Dichlorodifluoromethane                         *      '•*                   1,2,3
 Dichloroethane (1,1)                             *      1-3                   1,2,3
 Dichtoroethane (1,2-)                            *      !•*                   1,2,3
 Dichloroethene (1,1-)                            *      1.0                    4
 Dichloroethyl  ether                              *      8.2                   1,2,3
 Dichloroethylene (1,1-)                          *      1.2                   1,2,3
 Dichloroethylene (CIS) (1,2-)                    *      1.2                   1,2,3
 Dichloroethylene (trans) (1,2-)                  *      1.2                   1,2,3
 Dichloromethane                                 *      1.2                    4
 Dichlorophenot  (2,4-)                   *               6.0                    4
 Dichlorophenol  (2,6-)                   *               6.0                    4
 Dichloropropane (1,2-)                          *      1.4                    4
 Dichloro-2-butene  (1,4-)                         *      3.8                   1,2,3
 Dieldrin                                         *      28                    1,2,3
 Diethylphthalate                                *      6.4                   1,2,3
 Diethylstilbesterol                                     999                   1,2,3
 Diethyl-o-pyrazinyl- (0,0)                                                    1,2,3
 phosphorothioate                                *      28.3                   1,2,3
 Diisopropylfluorophosphate                       *      23.3                   1,2,3
 Dimethoate                                              289                   1,2,3
 Dimethoxybenzidine (3,3'-)                              999                   1,2,3
 Dimethyl sulfate                          *             0.05                   1,2,3
 Dimethylamine                                           999                   1,2,3
 Dimethylbenzidine (3,3'-)                               999                   1,2,3
 Dimethylbenz[A]anthracene (7,12-)                       999                   1,2,3
 Dimethylcarbamoyl chloride                 *             0.0029                 1,2,3
 Dimethylnitrosamine                                     999                   1,2,3
 Dimethylphenethylamine (a,a-)                    *      11.1                   1,2,3
 Dimethylphenol  (2,4-)                   *                3.0                    4
 Dimethylphthalate                          *             >12                  1,2,3
 Dinitrotoluene  (2,4-)                        *          12                      4a
 Dinitrotoluene  (2,6-)                        *         0.35                    5
 Dinitro-o-cresol (4,6-)                                75; <150              1,2,3
 Dinoseb                                         *      3.1                   1,2,3
 Dioxane (1,4-)                                  *      200                   1,2,3
 Diphenylhydrazine (1,2-)                             *  0.03                   6
Dipropylamine                          *               0.33                  1,2,3
Disulfoton                                             >5;  <67                1,2.3
                                          104

-------
                             TABLE B-l  (Continued)
                                          Dominant                +
                                          Process        Half-life        References &
 Waste Name                             B  H  P  V  0      (days)            Comments

 Di-n-octylphthalate                                                         1,2,3
 Di-n-propylnitrosamine                          *      25                   1,2,3
 Endosulfan                                      *      >5;  <14               1,2,3
 Endrin                                                 >5;  <68               1,2,3
 Epichlorohydrin                                 *      3.5                     4
 Ethtlene oxide                                  *      3.6                   1,2,3
 Ethyl acrylate                                  *      2.6                   1,2,3
 Ethyl carbamate                                        >365                  1,2,3
 Ethyl ether                                      *      1.2                   1,2,3
 Ethyl methacrylate                               *      2.4                   1,2,3
 Ethylene dibromide                               *      2.0                   1,2,3
 Ethylenimine                           *               5.0                   1,2,3
 Ethylmethanesulfonate                      *            0.8                     1
 Ethyl-4,4'-dichlorobenzilate                            >7.2                  1,2,3
 Etylenebis(dithiocarbamic acid)                         >365                  1,2,3
 Fluoranthene                                 *          15                      4a
 Fluoroacetamide                                        >365                  1,2,3
 Formaldehyde                                    *      .9                      4
 Formic  acid                                                                  1,2,3
 Furan                                           *      1.1                   1,2,3
 Furfural                                *               0.6                   1,2,3
 Glycidylaldehyde                           *             29                    1,2,3
 Heptachlor                                 *         *   0.5                    4,6
 Hexachlorobenzene                                *      2.0                     4
 Hexachlorobutadiene                     *               1.5                     4
 Hexachlorocyclohexane (a-)                              >365                  1,2,3
 Hexachlorocyclopentadiene                     *          0.2                     4a
 Hexachloroethane                                 *      1.1                     4
 Hexachlorohexahydro-exo.exo-                                                 1,2,3
 dimethanonaphthalene                            *      2.4                   1,2,3
 Hydrazine                                        *      75; <145              1,2,3
 Indeno(1,2,3-cd)pyrene                        *          3.8                     4a
 Isobutanol                              *               3.4                   1,2,3
 Isosafrole                                 *      *      >1; <47               1,2,3
 Kepone                                                                       1,2,3
 Lead                                                    999
 Maleic anhydride                           *             0.0003                  1
 Malononitrile                                           >365                  1,2,3
 Helphalan                                               <365                  1,2,3
 Mercury                                          *      1.7                     3
Methanol                                *                2.4                   1,2,3
Hethomyl                                                >365                  1,2,3
                                          105

-------
                             TABLE  B-l  (Continued)
 Waste Name

 Methyl  aziridine
 Methyl  Chlorocarbonate
 Methyl  ethyl  ketone
 Methyl  hydrazine
 Methyl  iodide
 Methyl  methacrylate
 Methyl  isocyanate
 Methyl  parathion
 Methylcholanthrene (3-)
 Methylene bromide
 Methylene chloride
 Methylenebis(Z-chloroaniline) (4,4'-)
 Methyllacetonitrile (2-)
 MethylthiouraciI
 Methyl-2-pentanone (4-)
 Mitomycin C
 Naphthalene
 Naphthalenedione (1,4-)
 Naphthylamine (1-)
 Naphthylamine (2-)
 Nickel
 Nickel carbonyl
 N i cot i ne
 Nitrobenzene
 Nitroglycerin
 Nitrophenol  (4-)
 Nitropropane (2-)
 Nitro-o-toluidine  (5-)
 n-Nitrosodiethanolamine
 N-Nitrosodiethylamine
 N-Nitrosomethylvinylamine
 N-Nitrosopiperidine
 N-Nitrosopyrrolidine
N-Nitroso-di-n-butylamine
 N-Nitroso-N-ethylurea
 N-nitroso-N-methyl  urethane
 N-Nitroso-N-methylurea
 N-Phenylthiourea
Octachlorocamphene
0-Nitrotoluene
Osmium tetroxide
Paraldehyde
Dominant
Process
B H P V
*
*
*
*
*
*
*
*
*
*
*



*

*

*
*

*

*


*
*

*
*
*
*
*
*
*
*

*
*
*
*
•f
Half-life
0 (days)
6.1
0.000024
2.0
<25
1.5
1.7
0.0058
90
2.0
2.2
1.2
>365
>365
>365
2.4
999
1.4

44
5.0
999
1.6
>365
12.5

* 14
1.2
2.6
999
250
3.3
2.9
14
1.8
31
1.8
69
>365
2.5
1.4
6.6
6.0

References &
Comments
1.2,3
1,2,3
4
1.2,3
1,2,3
1,2,3
1
1,2,3
1,2,3
1.2,3
1,2.3
1.2,3
1,2,3
1,2,3
1,2.3
1.2,3
1,2,3
1,2,3
1,2,3
1.2,3

1,2,3
1,2,3
4
2; explosive
6
1,2.3
1.2,3
1,2,3
1.2,3
1,2,3
1,2.3
1.2,3
1,2,3
1,2.3
1,2,3
1.2,3
1,2,3
1,2,3
5
1,2.3
1,2.3
                                         106

-------
                             TABLE B-l  (Continued)
 Waste Name

 Parathion
 PCB-1254
 PentachIorobenzene
 Pentachloroethane
 Pentachloroni trobenzene
 Pentachlorophenol
 Pentadiene (1.3-)
 Phenacetin
 Phenol
 Phenylmercuricacetate
 Phorate
 Phosgene
 Phosphine
 Phthalic anhydride
 Picoline (2-)
 Pronamide
 Propanamine (1-)
 Propane nitrile
 Propane sultone (1,3-)
 Propyn-1-o1  (2-)
 Pyrene
 Pyridinamine (4-)
 Pyridine
 p-Nitroaniline
 Reserpine
 Resorcinol
 Saccharin
 Safrole
 Selenium
 Selenium dioxide
 Silver
 Si Ivex
 Strychnine
 T(2,4,5)
 Tetrachlorobenzene (1,2,4,5-)
 Tetrachloroethane  (1,1,1,2-)
 Tetrachloroethane  (1,1,2,2)
 Tet rachIoroethene
 TetrachIoroethyIene
Tetrachloromethane
Tetrachlorophenol  (2,3,4,6-)
Tetrahydrofuran
Dominant +
Process Half -life
B H P V 0 (days)
* * 35
* 2.0
* 2.1
* 1.8
* 2.1
* 150
* 1.0
* 140
* 0.1
2.9
* 4.0
* 0.96

* 0.002
* 7.1
* 27
* 6.7
* 5.6
<365
NHYF
* 1.3
* 34
* 2.0

* 3
* 5
>365
* * >1;<19
999
260
999
999
999
999
* 3.9
* 1.6
* 1.8
* 1.4
* 1.6
* 1.5
* 1.8
* 2.2

References &
Comments
4
4
1,2,3
1,2,3
1,2,3
4a
1,2,3
1,2,3
4b
6
4
1,2,3
2; poisonous gas
1.2,3
1,2,3
1,2,3
1,2,3
1,2,3
1,2,3
1,2,3
5
1,2,3
4
1.2,3
1,2,3
1.2,3
1,2,3
1,2,3
7
3

1,2,3
1,2,3
1.2,3
1,2,3
1,2.3
4
4
1,2.3
1.2,3
1.2,3
1.2.3
                                         107

-------
                            TABLE B-l  (Continued)
                                          Dominant                +
                                          Process        Half-life         References &
Waste Name                              B  H  P  V   0      (days)            Comments

Tetranitromethane                                *       34                    1.2.3
Thiofanox                                               <365                   1.2,3
Toluene                                          *       1.0                     4
Toluene diamine                               *         30.0                     4a
Toluene diisocyanate                       *            0.0016                  1
Toluidine hydrochloride (a-)                     *       25                    1,2,3
Toxaphene                                        *       2.0                     4
Trichloroacetaldehyde                            *       1.7                   1,2,3
Trichloroethane  (1,1,1-)                         *       1-3                     4
Trichloroethane  (1,1,2-)                         *       1.8                   1,2,3
Trichloroethene                                  *       1.3                     4
Trichloroethylene                                *       1.4                   1,2,3
Trichloromethyl  mercaptan                        *       3.2                   1,2,3
Trichloromonofluoromethane                       *       1.4                   1,2,3
Trichlorophenol  (2,4,5-)                         *       36                    1,2,3
Trichtorophenol  (2,4,6-)                *               13                      4
Tris(2,3-dibromopropyl)phosphate                 *       5.6                   1,2,3
Triflurallin                                 *         0.63                     5
Urcil,5[Bis-2-chloromethylamino]                        >365                   1,2,3
Warfarin                                                180                   1,2,3
Xylene                                           *       1.5                     4
Zinc                                                    999

+    A half-life of 999 days is assigned for elements and substances
     with every  long half-lives.

1.   Wolfe  (1985)

2.   Environmental Monitoring and Services,  Inc.  (1985)

3.   Estimate using a method similar to that described in ICF
     (1984), except that the diffusion coefficients  were
     estimated using the formula sugested by HydroQual  (1982).
     The Henry's constants were from U.S.  EPA (1985).

4.    Environ (1984)

4a.   Modified from Environ (1984),  the photolysis half-life in Environ
     (1984)  is for mid-day,  near surface situation and  is  multiplied
     by a  factor of 30  to  represent a daily-average,  depth-average
     situation with the assumptions of a 2m  depth of  water  and a
     diffusion attenuation coefficient of  10 m-1.
                                          108

-------
                           TABLE  B-l  (Concluded)
                                         Dominant                +
                                         Process        Half-life        References &
Waste Name                             B  H  P  V  0      (days)            Comments
4b.  Photolysis uas one of  the dominant processes according to  Environ
     (1984),  however,  after the adjustment for a typical  surface
     water environment as described  in 4a, biodegradation becomes
     the only dominant process.

5.   Modified from Zepp et  al., (1984), the literature value is
     multiplied by a factor of 30 to represent a daily-average,
     depth-average situation with the assumption of a 2m  depth  of
     water and a diffusion  attenuation coefficient of 10m-1.

6.  Estimated by using the  oxidation constants given in Mabey et al.
    (1982),  and assuming peroxy radical conc.= 10E-9H,
    single oxygen conc.=10E-12M.

7.   Callahan et al.,  (1979)
                                         109

-------
                             APPENDIX C




      ILLUSTRATIVE  HALF-LIVES  OF  SUBSTANCES  IN LAKES/RESERVOIRS




     The half-life values presented in this appendix are based on a




limited sample of comprehensive literature review articles.   As a




result, the half-life values in the appendix may not  be the  best




available estimates.  Moreover, the values in these review articles




may not have been estimated in a manner consistent with the




methodology described in Appendix G.  As a result, these half-life




values should be used for illustrative purposes  only.  Specifically,




these values were collected for preliminary assessment on the




availability of the data, and to estimate the feasibility and




sensitivity of the proposed ranking methods.
                                Ill

-------
                                  TABLE  C-l
 ILLUSTRATIVE  HALF-LIVES  OF  SUBSTANCES  IN  LAKES/RESERVOIRS
 Waste Name

 Acenaphthytene
 Acetaldehyde
 Acetone
 Acetonitrile
 Acetophenone
 Acetyl Chloride
 Acetylaminofluorene (2-)
 Acrolein
 AeryI amide
 Acrylonitrile
 Aldicarb
 ALdrin
 AUyl alcohol
 Ammoniun Picrate
 Aniline
 Anthracene
 Arsenic
 Arsenic III oxide
 Asbestos
 a-Chlorophenylthiourea (1-)
 a-naphthylthiourea
 Benzacridine (3,4-)
 Benzal  chloride
 Benzanthracene (1,2-)
 Benzenethiol
 Benzene
 Benzene, 1,3,5-trinitro
 Benzensulfonyl  Chloride
 Benzidine
 Benzo(a)anthracene
 Benzo(b)fluoranthene
 Benzo(a)pyrene
 Benzoquinone (p-)
 Benzotrichloride
 Benzo[a]pyrene
 Benzyl Chloride
Benzylchloride
Bioxirane (2,2-)
Bis-2-chloroisopropyl  ether
Bis(chloromethyl)ether
Bis-2-chloromethoxymethane
Bromoacetone
Dominant +
Process Half -life
B H P V 0 Days
* 3.8
* * 1.0
* 5
* 7.0
19
* 0.0000006
>365
* 6
999
* * 5.1
>365
* 17
* 8
* 43
* 53
* 1.3
999
999
999
>365
>365
999
* 0.005
999
* 7.8
* 7.0
* 11.5
* 0.0026
* 0.262
* 3.8
* 3.8
* 1.2
>5
* 0.002
999
* 0.37
* 8.7
* 29
* 11.7
* 0.000129
>365
• 182

References
& Comments
4a
4
1,2,3
4
1,2,3
1,2,3
1,2,3
1,2,3
1,2,3
4
1,2,3
1,2,3
1,2,3
1,2,3
1,2,3
5
1,2,3
1,2,3
7
1,2,3
1,2,3
1,2,3
1,2,3
1,2,3
1,2,3
4
1,2,3
1,2,3
6
4a
4a
4a
1,2,3
1,2,3
1,2,3
1,2,3
1,2,3
1,2,3
1,2,3
1
1,2,3
1,2,3
                                      112

-------
                           TABLE  0-1  (Continued)
 Waste Name

 Bromoform
 Bromomethane
 Bromopropyl phenyl ether (4-)
 Brucine
 Butanol (n-)
 Butanone (2-)
 Cadmium
 Carbon tetrachloride
 Chlorambucil
 Chlordane
 Chlornaphazine
 Chloroacetaldehyde
 Chloroaniline (p-)
 Chlorobenzene
 Chlorodane
 Chloroethene
 Chloroethyl vinyl ether (2-)
 Chloroform
 Chloromethane
 Chloromethyl methyl ether
 Chloconapthalene (B-)
 Chlorophenol (o-)
 Chloropropionitrile (3-)
 Chloro-2,3-epoxypropane (1-)
 Chloro-m-cresol (4-)
 Chloro-o-toluidine (4-)
 Chromium
 Chrysene
 Copper
 Cresols
 Crotonaldehyde
 Cumene
 Cyclohexane
 Cyclohexanone
 Cyclohexyl-4,6-dinitrophenol (2-)
 CycIophosphamide
 Daunomycin
 ODD
 DDT
 D(2,4)
D(2,4) salts and esters
Dial late
Dominant
Process
8 H P V 0
*
*
*

*
*

*
*
*

*
*
*
*
*
*
*
*
*
*

*
*

*



*

* *
*
*
*


*
*


*
+
Half-life
Days
13
6.7
12.8
>365
24
11
999
7.3
>365
16
>365
6.1
63
7.8
15.7
5
7.4
6.6
4.3
0.00029
10.0
>5; <44
46.6
10
>365
26
999
6
999
8
>5; <16
4
6
13
13
>365
>365
15
21
999
>365
>5; <15

References
& Comments
,2,3
.2.3
,2.3
.2,3
,2,3
,2.3
1,2,3
4
1,2,3
1,2.3
1.2.3
1.2,3
1,2,3
4
4
1,2.3
1.2,3
4
1.2.3
1,2,3
1,2.3
1,2,3
1,2,3
1.2,3
1,2,3
1.2.3
1.2.3
4a
1,2.3
1,2.3
1,2,3
1,2.3
1,2,3
1,2,3
1,2.3
1,2,3
1,2,3
1.2,3
1,2,3
1.2,3
1,2,3
1.2.3
                                     113

-------
                           TABLE C-l  (Continued)
 Waste  Name

 Dibenzopyrene  (1,2,7,8-)
 D i benz[a,h]anthracene
 Dibromo-3-Chloropropane (1,2-)
 Dibutylphthalate
 Dichlorobenzene (1,2)
 Dichlorobenzene (1,4)
 Dichlorobenzidine (3,3'-)
 Dichlorodifluoromethane
 Dichloroethane (1,1)
 Dichloroethane (1,2)
 Dichloroethene (1,1)
 Dichloroethyl ether
 Oichloroethylene (1,1-)
 Dichloroethylene (CIS) (1,2-)
 Dichloroethylene (trans) (1,2-)
 Dichloromethane
 Dichlorophenol (2,4)
 Dichlorophenol (2,6)
 Dichloropropane (1,2-)
 Dichloropropane (1,3-)
 Dichloro-2-butene (1,4-)
 Dieldrin
 Diethylenedioxide (1,4-)
 Diethylphthalate
 Diethylstilbesterol
 Diethyl-o-pyrazinyl- (0,0)
 phosphorothioate
 Di isopropylfluorophosphate
 Dimethoate
 Dimethoxybenzidine (3,3'-)
 Dimethyl sulfate
 Dimethylamine
 Dimethylbenzidine (3,3'-)
 Dimethylbenz[A]anthracene (7,12-)
 Dimethylcarbamoy chloride
 Dimethylfuran
 Dimethylnitrosamine
 Dimethylphenethylamine (a,a-)
 Dimethylphenot  (2,4)
Dimethylphthalate
Dinitrotoluene  (2,4-)
Dinitrotoluene  (2,6-)
                                          Dominant
                                          Process
                                        B  H  P  V  0
  Half-life
     Days

 999
 3.8
 14
 >80;  <230
 8.5
 8.5
 0.06
 7.8
 6.9
 7.0
 2.7
 16
 6.8
 6.8
 6.8
 5.8
 6.0
 6.0
 7.5
 7.6
 10
 >5; <42
 >5; <200
 16
 999
 25

 32
 290
 999
 0.05
 999
 999
 999
 0.0029
 0.15
 999
 19
3.0
>12
 12
0.35
References
& Comments
   1,2.3
    4a
   1.2,3
   1,2,3
     4
     4
     5
   1,2,3
   1,2,3
   1,2,3
     4
   1,2,3
   1.2.3
   1,2,3
   1.2,3
     4
     4
     4
    .2,3
    .2,3
    .2,3
    .2,3
    .2,3
    .2,3
    .2,3
    ,2.3

    ,2,3
    ,2,3
    ,2.3
    ,2.3
    ,2.3
    ,2,3
    ,2,3
    ,2.3
     5
   1,2.3
   1.2,3
     4
   1,2,3
   4a
     5
                                        114

-------
                          TABLE C-l  (Continued)
 Waste Name

 Dinitro-o-cresol (4,6-)
 D i noseb
 Dioxane  (1,4-)
 Diphenylhydrazine (1,2-)
 Dipropylanrine
 Disulfoton
 Di-n-octylphthalate
 Di-n-propylnitrosamine
 Endosulfan
 Endrin
 Epichlorohydrin
 Ethtlene oxide
 Ethyl acrylate
 Ethyl acrylate
 Ethyl carbamate
 Ethyl ether
 Ethyl Hethacrylate
 Ethylene dibromide
 Ethylenimine
 Ethylmethanesulfonate
 Ethyl-4,4'-dichlorobenzilate
 Etylenebis(dithiocarbamic acid)
 Fluoranthene
 Fluoroacetamide
 Formaldehyde
 Formic acid
 Furan
 Furfural
 Glyeidylaldehyde
 Heptachlor
 Hexachlorobenzene
 HexachIorobutadi ene
 Hexachlorocyclohexane (a-)
 HexachlorocycIopentadi ene
 Hexachloroethane
 Hexachlorohexahydro-exo,exo-
 dimethanonaphthaiene
HexachIoropropene
Hydrazine
 Ideno(1,2,3-Cd)pyrene
Isobutanol
Isosafrole
Dominant
Process
B H P V 0

*
*
*
*
* *

*


* *
* *
*
*

*
*
*
*
*


*

* *

*
*
*
* *
*
*
*
*
* *

*
*


*

4-
Half-life
Days
>5; <160
14
205
0.03
0.33
>5; <36
999
31
>5; <29
>5; <83
4.7
4.3
8.1
5.5
>365
6
8.6
11
5
0.8
>7.2; <458
>365
15
999
1.6
237
5.3
0.6
75; <29
0.5
11.0
7.3
>365
0.02
2.6

16
13
>5; <147
3.8
3.4
>5; <55

References
& Comments
1.2,3
1,2,3
1,2,3
6
1.2,3
1,2,3
1,2,3
1,2,3
1,2,3
1,2,3
4
1,2,3
1,2,3
1,2,3
1,2,3
1,2,3
,2,3
,2,3
,2,3
,2,3
,2,3
,2,3
4a
1,2,3
4
1,2,3
1,2,3
1,2,3
1,2,3
4,6
4
4
1,2,3
4a
4
1,2,3
1,2,3
1.2,3
1,2,3
4a
1,2,3
1,2,3
                                      115

-------
                          TABLE  C-l (Continued)
 Waste Name

 Kepone
 Lead
 Lindane
 Maleic anhydride
 Malononitrile
 Melphalan
 Methanol
 Hethapyriline
 Methomyl
 Methyl aziridine
 Methyl Chlorocarbonate
 Methyl ethyl  ketone
 Methyl hydrazine
 Methyl iodide
 Methyl methacrylate
 Methyl parathion
 Methylcholanthrene (3-)
 Methylene bromide
 Methylene chloride
 Methylenebis(2-chloroaniline) (4,4'-)
 Methyllacetonitrile (2-)
 MethylthiouraciI
 Methyl-2-pentanone (4-)
 Mitomycin C
 Naphthalene
 Naphthalenedione (1,4-)
 Naphthylamine (1-)
 Naphthylamine (2-)
 Nickel
 Nickel carbonyl
 Nicotine
 Nitrobenzene
 Nitroglycerin
 Nitrophenol (4-)
 Nitropropane (2-)
 Nitro-o-toluidine (5-)
 n-Nitrosodiethanolamine
 N-Nitrosodiethylamine
 N-Nitrosomethylvinylamine
 N-Nitrosopiperidine
N-Nitrosopyrrolidine
N-Nitroso-di-n-butylamine
                                          Dominant
                                          Process
                                        B  H  P  V  0
Half-life
Days

999
>365
0.0003
>365
>365
2.4

>365
5.2
0.000024
3.3
38
8.7
7.4
90
13
11
6.2
>365
>365
>365
8.0
999
6.2
60
51
5
999
9.9
999
18.8

14
6.4
11
999
256
7.9
4.1
20.0
9.6
References
& Comments
1.2.3

1,2.3
1,2,3
1,2.3
1.2,3
1,2,3
1.2.3
1.2.3
1,2.3
1.2.3
4
1,2,3
1,2.3
1,2,3
1,2.3
1.2,3
1,2.3
1,2.3
1.2,3
1.2,3
1,2.3
1.2.3
1,2,3
1,2,3
1.2,3
1.2.3
1,2.3
1,2,3
1,2,3
1.2,3

1,2,3
6
1.2,3
1,2,3
1.2.3
1.2.3
1.2,3
1.2,3
1.2,3
1.2,3
                                       116

-------
                          TABLE  C-l  (Continued)
 Waste Name

 N-Nitroso-N-ethylurea
 N-nitroso-N-methyl urethane
 N-Nitroso-N-methylurea
 N-Phenylthiourea
 OctachIorocamphene
 Osmium tetroxide
 0-Nitrotoluene
 Paraldehyde
 Parathion
 PCB-1254
 PentachIorobenzene
 PentachIoroethane
 Pentach I oron i t robenzene
 PentachIorophenol
 Pentadiene (1,3-)
 Phenacetin
 Phenol
 Phenylmercuricacetate
 Phorate
 Phosgene
 Phosphine
 Phthalic anhydride
 Picoline (2-)
 Pronamide
 Propanamine (1-)
 Propane nitrile
 Propane sultone (1,3-)
 Propyn-1-o1 (2-)
 Pyrene
 Pyridinamine (4-)
 Pyridine
 p-Nitroaniline
 Reserpine
 Resorcinol
 Saccharin
 Safrole
 Selenium
 Silver
 Si Ivex
Strychnine
T(2,4,5)
Tetrachlorobenzene  (1,2,4,5-)
Dominant
Process
B H P V 0
*
*
*

*
*
*
*
* *
*
*
*
*

*

*

*
*
*
*
*
*
*
*


*
*
*
*
*
it







*
+
Half-life
Days
37
8.7
75
>365
18
18
1.4
13
35
2.0
13
11
14
>365
5.3
150
0.1
2.9
4.0
0.96
3.34
0.002
12.5
38
11
9.3
<365
999
1.3
39
2.0
180
23
5
>365
>1; <27
999
999
999
999
999
14

References
& Comments
1,2,3
1,2,3
1,2,3
1,2,3
1.2,3
1.2,3
5
1,2,3
4
4
1.2.3
1.2,3
1.2,3
1,2,3
1.2,3
1,2,3
4b
6
4
,2.3
.2.3
.2.3
.2.3
,2.3
,2.3
,2,3
,2.3
,2,3
5
1,2,3
4
1,2,3
1,2,3
1,2,3
1.2.3
1,2,3
7
1,2,3
1,2,3
1,2,3
1.2,3
1,2,3
                                       117

-------
                          TABLE  C-l  (Continued)
                                          Dominant                   +
                                          Process           Half-life    References
 Waste Name                             B  H  P  V  0          Days      & Comments

 Tetrachloroethane  (1,1,1,2-)                     *         9.8              1,2,3
 Tetrachloroethane  (1,1,2,2)                      *         8.6                4
 Tetrachloroethene                                *         7.9                4
 Tetrachloroethylene                              *         9.7              1,2,3
 Tetrachtoromethane                              *         9.2              1,2,3
 Tetrachlorophenol  (2,3,4,6-)                     *         12               1,2,3
 Tetrahydrofuran                                  *         6.7              1,2,3
 Tetranitromethane                                *         43               1,2,3
 Thiofanox                                  *               >365             1,2,3
 Toluene                                         *         7.9                4
 Toluene diamine                               *            30.0               4
 Toluene diisocyanate                       *               0.002              1
 Toluidine  hydrochloride (a-)                     *         32               1,2,3
 Toxaphene                                        *         14.2               4
 Trichloroacetaldehyde                            *         9                1,2,3
 Trichloroethane (1,1,1)                          *         7.2                4
 Trichloroethane (1,1,2-)                         *         11                1,2,3
 Trichloroethene                                  *         7.2                4
 Trichloroethylene                                *         8.3              1,2,3
 Trichloromethyl mercaptan                        *         11                1,2,3
 Trichloromonoftuoromethane                       *         8.5              1,2,3
 Trichlorophenol (2,4,5-)                         *         45                1,2,3
 Trichlorophenol (2,4,6)                 *                   13                  4
 Trinitrotoluene (2,4,6)                                    15                4a
 Tris(2,3-dibromopropyl)phosphate                 *         28                1,2,3
 Urcil,5[Bis-2-chloromethylamino]            *                <365              1,2,3
 Warfarin                                   *                180              1,2,3
 Xylene                                           *         9.0                4
 Zinc                                                       999

 +   A half-life of 999 days is assigned for elements and substances
    with very long half-lives.

 1.  Wolfe (1985)

2.  Environmental  Monitoring  and  Services,  Inc. (1985)

3.  Estimate using a  method similar  to  that described in ICF
    (1984), except  that the diffusion coefficients were
    estimated using the formula suggested by HydroQual (1982).
    The Henry's constants  were from  EPA  (1985).
                                       118

-------
                         TABLE  C-l  (Concluded)
                                         Dominant                   +
                                         Process           Half-life    References
Waste Name                              B   H  P  V  0          Days      & Comments

4.  Environ (1984)

4a. Modified from Environ (1984),  the  photolysis half-life in Environ
    (1984) is for mid-day,  near surface  situation and is multiplied
    by a factor of 30 to represent a daily-average, depth-average
    situation with the assumptions of  a  2m  depth of water and a
    diffusion attenuation coefficient  of 10 m-1.
4b. Photolysis was one of the dominant  processes according to Environ
    (9184), however,  after the adjustment  for a typical surface
    water environment as described in 4a,  biodegradation becomes
    the only dominant process.

5.  Modified from Zepp et al., (1984),  the literature value is
    multiplied by a factor of 30  to represent a daily-average,
    depth-average situation with  the assumption of a 2m depth of
    water and a diffusion attenuation coefficient of 10m-1.

6.  Estimated using the oxidation constants given in Mabey et al.
    (1982) and assuming peroxy radical  conc.=10E-9M,
    single oxygen conc.=10E-12M.

7.  Callahan et al.,  (1979)
                                      119

-------
                             APPENDIX D



          LOGARITHM N-OCTANOL-WATER COEFFICIENTS (LOG Pow)



     Table D-l presents a range of log P   values from a



computerized data base (Technical Database Services, Inc., 1985).



For a limited number of substances found at waste sites, and which



are not included in the computerized data base, MITRE calculated



log P   values or found log P   values in the literature.  These
     ow                      ow


values are presented in Table D-2.
                                 121

-------
               TABLE D-l




LOGARITHM N-OCTANOL-WATER COEFFICIENTS
Substance Name
1,1, 1 -TRICHLOROETHANE /EPA/
1,1,2, 2 -TETRACHLOROETHANE
1,1, 2 -TRICHLOROTRIFLUOROETHANE
1,1-DICHLOROETHANE /BPA/
1, 1-DICHLOROETHYLENE/VlNYLIDINE CHLORIDE/
1 , 2 , 3-TRICHLOROBENZENE
1,2,3- TRIMETHYLBENZENE
1,2,4, 5 -TETRACHLOROBENZENE
1 , 2 ,4-TRICHLOROBENZENE
1,2,4- TRIMETHYLBENZENE
1,2,5 , 6-DIBENZANTHRACENE
1,2-DIBROMOETHANE
1,2-DICHLOROETHANE /BPA/
1,2-DICHLOROETHYLENE -CIS
1,2-DICHLOROETHYLENE -TR
1 , 3 , 5-TRIMETHYLBENZENE/MESITYLENE/
1,3,5- TRINITROBENZENE
1,3 -BUTADIENE /BPA/
1 , 3 - DICHLOROBENZENE
1,4- NAPHTHOQUINONE
(Source: Technical Database Services, Inc., 1985)
122
CAS Number
71-55-6
79-34-5
76-13-1
75-34-3
75-35-4
87-61-6
526-73-8
95-94-3
120-82-1
95-63-6
53-70-3
106-93-4
107-06-2
156-59-2
156-60-5
108-67-8
99-35-4
106-99-0
541-73-1
130-15-4


Log Pow
2.49
2.39
3.16
1.79
2.13
3.99
3.66
4.82
4.12
3.78
6.50
1.96
1.48
1.86
2.09
3.42
1.18
1.99
3.38
1.78



-------
TABLE D-l (Continued)
Substance Name
1-BUTENE /BPA/
1-CHLOROBUTANE /BPA/
1 - ETHYL- 1 -NITROSOUREA/ENU/
1 - ETHYL- 2 - METHYLBENZENE
1 -METHYL- 1 - NITROSOUREA
1 - PROPENE , 1 - PHENYL
2,2' -DICHLOROETHYLETHER
2,2, 2 -TRICHLORO- 1 , 1 - ETHANEDIOL/CHLORALHYDRATE
2,3,4, 5 -TETRACHLOROPHENOL
2,3,4,6- TETRACHLOROPHENOL
2 , 3 ,4-TRICHLOROPHENOL
2 , 3 , 4-TRICHLOROPHENOL
2,3,5, 6 -TETRACHLOROPHENOL
2,3, 5 -TRICHLOROPHENOL
2,3, 6 -TRICHLOROPHENOL
2 , 3-DICHLOROPHENOL
2,4,5- TRICHLOROPHENOL
2,4, 6 -TRICHLOROPHENOL
2,4,6- TRINITROTOLUENE
2 , 4-DICHLOROPHENOL
CAS Number
106-98-9
109-69-3
759-73-9
611-14-3
684-93-5
637-50-3
111-44-4
302-17-0
4901-51 3
58-90-2
15950-66-0
15950-66-0
935-95-5
933-78-8
933-75-5
576-24-9
95-95-4
88-06-2
118-96-7
120-83-2
Log Pow
2.40
2.64
-0.15
3.53
-0.16
3.35
1.29
1.61
5.05
4.10
3.51
3.51
4.88
4.56
3.46
2.52
3.72
3.62
1.60
3.30
        123

-------
TABLE D-l (Continued)
Substance Name
2,4- DIMETHYLPHENOL
2 , 4-DINITROPHENOL
2 , 4-DINITROTOLUENE
2 , 5 -DICHLOROPHENOL
2,6-DICHLOROPHENOL
2-BUTANONE
2-HEXANONE
2-NITROGUANIDINE
2 - PENTANONE
2 -PICOLINE/2 -METHYL PYRIDINE/
3,3' -DICHLOROBENZIDINE
3,4, 5 -TRICHLOROPHENOL
3, 4 -DICHLOROPHENOL
3-METHIO-4-AMINO-6-T-BU-l,2,4-TRIAZINE-5-ONE
3-METHIO-4-AMINO-6-T-BU-l,2,4-TRIAZINE-5-ONE
4 , 4 ' - 1 - PROPYLIDENE- DIPHENOL/DIPHENYLOLPROPANE
4.4--PCB
4,4'-STILBENEDIOL,A,A'-DIETHYL/DES/
4-AMINOPYRIDINE
4 - NITROQUINOLINE - 1 - OXIDE
CAS Number
105-67-9
51-28-5
121-14-2
583-78-8
87-65-0
78-93-3
591-78-6
556-88-7
107-87-9
109-06-8
91-94-1
609-19-8
95-77-2
21087-64-9
21087-64-9
80-05-7
2050-68-2
56-53-1
504-24-5
56-57-5
Log Pow
2.30
1.50
1.98
3.20
2.34
0.29
1.38
-0.89
0.91
1.11
3.51
4.01
2.86
1.70
1.70
3.32
5.58
5.07
0.26
1.02
          124

-------
TABLE D-l (Continued)
Substance Name
6-AMINOCHRYSENE
7 , 12 -DIMETHYLBENZC A) ANTHRACENE
A , A , A - TRI CHLOROTOLUENE
A- CHLOROTOLUENE
A-NAPHTHYLAMINE
A- NAPHTHYLTHIOUREA/ANTU/
ACENAPHTHENE
ACETANILIDE , 4 - ETHOXY/PHENACETIN/
ACETIC ACID
ACETIC ACID, ETHYL ESTER
ACETIC ACID, METHYL ESTER
ACETIC ACID, BUTYL ESTER
ACETIC ACID.PROPYL ESTER
ACETONE
ACETONITRILE
ACETOPHENONE
ACETYLENE /BPA/
ACRIDINE
ACRYLAMIDE
ACRYLIC ACID, BUTYL ESTER
CAS Number
218-01-9
57-97-6
98-07-7
100-44-7
134-32-7
86-88-4
83-32-9
62-44-2
64-19-7
141-78-6
79-20-9
123-86-4
109-60-4
67-64-1
75-05-8
98-86-2
74-86-2
260-94-6
79-06-1
141-32-2
Log Pow
4.98
5.80
2.92
2.30
2.25
1.66
3.92
1.58
-0.17
0.73
0.18
1.82
1.24
-0.24
-0.34
1.73
0.37
3.40
-0.67
2.36
       125

-------
TABLE D-l (Continued)
Substance Name
ACRYLIC ACID, METHYL ESTER
ACRYLIC ACID, ETHYL ESTER
ACRYLONITRILE
ADIPIC ACID
ALACHLOR/LASSO/
ALACHLOR/LASSO/
ALDICARB/TEMIK/
ALLYL ALCOHOL
ANILINE
ANILINE, N-METHYL
ANTHRACENE
ARGON /BPA/
AZOBENZENE , 4 - DIMETHYLAMINO
B-NAPHTHYLAMINE
BENZALDEHYDE
BENZENE
BENZIDINE
BENZO(A)PYRENE
BENZOIC ACID
BENZONITRILE
CAS Number
96-33-3
140-88-5
107-13-1
124-04-9
15972-60-8
15972-60-8
116-06-3
107-18-6
62-53-3
100-61-8
120-12-7
7440-37-1
60-11-7
91-59-8
100-52-7
71-43-2
92-87-5
50-32-8
65-85-0
100-47-0
Log Pow
0.80
1.32
-0.92
0.08
3.52
3.52
0.70
0.17
0.90
1.82
4.45
0.74
4.58
2.28
1.48
2.13
1.34
5.97
1.87
1.56
         126

-------
TABLE D-l (Continued)
Substance Name
BENZOPHENONE
BENZOTHIAZOLE
BIPHENYL
BROMOBENZENE
BROMOCHLOROMETHANE
BUTANE /BPA/
BUTANOL
BUTOXYETHANOL
BUTYL BENZOATE
BUTYLAMINE
BUTYLBENZENE
BUTYLBENZYLPHTHALATE
BUTYRALDEHYDE
CAPTAN
CARBOFURAN
CARBON TETRACHLORIDE /BPA/
CHLORAMBUCIL/NCS 3088/
CHLOROBENZENE
CHLORODIFLUOROMETHANE/FREON-22/ BPA/
CHLOROFORM
CAS Number
119-61-9
95-16-9
92-52-4
108-86-1
74-97-5
106-97-8
71-36-3
111-76-2
136-60-7
109-73-9
104-51-8
85-68-7
123-72-8
133-06-2
1563-66-2
56-23-5
305-03-3
108-90-7
75-45-6
67-66-3
Log Pow
3.18
2.01
3.95
2.99
1.41
2.89
0.88
0.83
4.21
0.88
4.26
3.97
0.88
2.35
2.32
2.83
1.70
2.84
1.08
1.97
         127

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TABLE D-l (Continued)
Substance Name
CHLOROTRIFLUOROMETHANE/FREON 13/BPA/
CYCLOHEXANE /BPA/
CYCLOHEXANOL
CYCLOHEXANONE
CYCLOHEXYLAMINE
CYCLOPROPYLBENZENE
CYTOXAN/CYCLOPHOS PHAMIDE/
DDE
DDT
DECANE
DEMETONTHIOL
DI- (P-AMINOPHENYL)METHANE
DI - 2 - ETHYLHEXYLPHTHALATE
DI - I - PROPANOLAMINE
DIBENZOFURAN
DIBUTYL ETHER
DICHLORODIFLUOROMETHANE/FREON-12/BPA/
DICHLOROFLUOROMETHANE/FREON- 2 I/ BPA/
DICOFOL
DIETHANOLAMINE
CAS Number
75-72-9
110-82-7
108-93-0
108-94-1
108-91-8
873-49-4
50-18-0
72-55-9
50-29-3
124-18-5
298-04-4
101-77-9
117-81-7
110-97-4
132-64-9
142-96-1
75-71-8
75-43-4
115-32-2
111-42-2
Log Pow
1.65
3.44
1.23
0.81
1.49
3.27
0.63
4.87
3.98
5.01
1.93
1.59
3.98
-0.82
4.12
3.21
2.16
1.55
3.54
1.43
         128

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TABLE D-l (Continued)
Substance Name
DIETHYLAMINE
DIETHYLPHTHALATE
DIMETHOATE
DIMETHOXYMETHANE
DIMETHYLAMINE
DIMETHYLFORMAMIDE
DIMETHYLPHTHALATE
DINOSEB
DIOXANE
DIPHENYLAMINE
DIPHENYLNITROSAMINE
DIPROPYLAMINE
DIPROPYLNITROSAMINE
DODECANOIC ACID/LAURIC ACID/
ETHANE /BPA/
ETHANE -1,2- DIOL/ETHYLENE GLYCOL/
ETHANOLAMINE
ETHION
ETHYL CHLORIDE/BPA/
ETHYL ETHER
CAS Number
109-89-7
84-66-2
60-51-5
109-87-5
124-40-3
68-12-2
131-11-3
88-85-7
123-91-1
122-39-4
86-30-6
142-84-7
621-64-7
143-07-7
74-84-0
107-21-1
141-43-5
563-12-2
75-00-3
60-29-7
Log Pow
0.57
2.47
0.50
0.00
-0.38
-1.01
1.56
2.30
-0.42
3.34
3.13
1.73
1.36
4.20
1.81
-1.93
-1.31
5.07
1.43
0.77
         129

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TABLE D-J.  (Continued)
Substance Name
ETHYLAMINE
ETHYLBENZENE
ETHYLENE
ETHYLENE OXIDE /BPA/
FLUORANTHENE
FLUORENE
FLUOROACETAMIDE
FLUOROFORM/BPA/
FORMALDEHYDE
FORMALDEHYDE
FORMIC ACID
FURAN /BPA/
FURFURAL
GLYCEROL /BPA/
GLYCERYL TRINITRATE
HEPTANE
HEXACHLORO -1,3- BUTADI ENE
HEXACHLOROBENZENE
HEXACHLOROCYCLOHEXANE , ALPHA ISOMER//124/356/
HEXACHLOROCYCLOHEXANE , BETA ISOMER//135/246/
CAS Number
75-04-7
100-41-4
74-85-1
75-21-8
206-44-0
86-73-7
640-19-7
75-46-7
50-00-0
50-00-0
64-18-6
110-00-9
98-01-1
56-81-5
55-63-0
142-82-5
87-68-3
118-74-1
319-84-6
319-85-7
Log Pow
-0.13
3.15
1.13
-0.30
5.20
4.18
-1.05
0.64
0.35
0.35
-0.54
1.34
0.41
-1.76
1.62
4.66
4.74
4.13
3.80
3.78
          130

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TABLE D-l (Continued)
Substance Name
HEXACHLOROCYCLOHEXANE/BHC/ GAMMA ISOMER
HEXACHLOROCYCLOPENTAD I ENE
HEXACHLOROETHANE
HEXACHLOROPHENE /PKA2=11.33/
HEXANE
HYDRAZINE
HYDRAZOBENZENE
HYDROCYANIC ACID /BPA/
I-BUTANOL
I-PROPANOL
I-PROPYLAMINE
IMIDAZOLIDONE , 2 -THIO/ETHYLENETHIOUREA/
INDENE
ISOPROPYLBENZENE
M-CHLOROPHENOL
M- DIHYDROXYBENZENE/RESORCINOL/
M-DINITROBENZENE
M-XYLENE
MALATHION
MALEIC ACID HYDRAZIDE /3 , 6-DIHYDROXYPYRIDAZIN
CAS Number
58-89-9
77-47-4
67-72-1
70-30-4
110-54-3
302-01-2
122-66-7
74-90-8
78-83-1
67-63-0
75-31-0
96-45-7
95-13-6
98-82-8
108-43-0
108-46-3
99-65-0
108-38-3
121-75-5
123-33-1
Log Pow
3.61
5.04
3.82
2.62
3.90
-2.07
2.94
-0.25
0.76
0.05
-0.03
-0.66
2.92
3.66
2.50
0.80
1.49
3.20
2.89
-0.84
         131

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TABLE D-l (Continued)
Substance Name
METHACRYLIC ACID, ETHYL ESTER
METHACRYLIC ACID, METHYL ESTER
METHACRYLONITRILE
METHANE /BPA/
METHANOL
METHOMYL
METHOMYL
METHOXYCHLOR
METHYL BROMIDE /BPA/
METHYL CHLORIDE/BPA/
METHYL IODIDE
METHYLAMINE
METHYLHYDRAZINE
METOLACHLOR
METOLACHLOR
MORPHOLINE
MUSCIMOL
N.N-DIMETHYLANILINE
N - METHYLCARBAMATE , 1 - NAPHTHYL
N-NITROSODIBUTYLAMINE
CAS Number
97-63-2
80-62-6
126-98-7
74-82-8
67-56-1
16752-77-5
16752-77-5
72-43-5
74-83-9
74-87-3
74-88-4
74-89-5
60-34-4
51218-45-2
51218-45-2
110-91-8
2763-96-4
121-69-7
63-25-2
924-16-3
Log Pow
1.94
1.38
0.68
1.09
-0.64
1.08
1.08
3.31
1.19
0.91
1.69
-0.57
-1.05
3.13
3.13
1.08
-2.39
2.31
2.36
1.92
         132

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TABLE D-l (Continued)
Substance Name
N-NITROSODIETHYLAMINE
N-NITROSODIMETHYLAMINE
N-NITROSOPIPERIDINE
N-NITROSOPYRROLIDINE
NAPHTHALENE
NITROBENZENE
NITROETHANE
NITROMETHANE
NONANE
0-AMINOPHENOL
0-CHLOROPHENOL
0-CHLOROTOLUENE
0-DIBUTYLPHTHALATE
0-DICHLOROBENZENE
0-DINITROBENZENE
0 - DIOCTYLPHTHALATE
0- ETHYL CARBAMATE/URETHANE/
0-HYDROXYBENZOIC ACID/SALICYLIC ACID/
0-METHYLBENZENESULFONAMIDE
0-NITROPHENOL
CAS Number
55-18-5
62-75-9
100-75-4
930-55-2
91-20-3
98-95-3
79-24-3
75-52-5
111-84-2
95-55-6
95-57-8
95-49-8
84-74-2
95-50-1
528-29-0
117-84-0
51-79-6
69-72-7
88-19-7
88-75-5
Log Pow
0.48
-0.57
0.63
-0.19
3.59
1.85
0.18
-0.33
4.51
0.62
2.17
3.42
4.72
3.38
1.58
5.22
-0.15
2.26
0.84
1.26
         133

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TABLE D-l (Continued)
Substance Name
0-PHTHALIC ACID
0-TOLIDINE
0-XYLENE
OCTANE
OCTANOL
P-AMINOPHENOL
P-CHLOROANILINE
P-CHLOROBIPHENYL
P-CHLORO PHENOL
P-DICHLOROBENZENE
P - DIHYDROXYBENZENE/HYDROQUINONE/
P-DINITROBENZENE
P-NITROANILINE
P-NITROPHENOL
P-NITROTOLUENE
P-XYLENE
PARALDEHYDE
PARAOXON
PARATHION
PENTACHLOROBENZENE
CAS Number
88-99-3
119-93-7
95-47-6
111-65-9
111-87-5
123-30-8
106-47-8
2051-62-9
106-48-9
106-46-7
123-31-9
100-25-4
100-01-6
100-02-7
99-99-0
106-42-3
123-63-7
311-45-5
56-38-2
608-93-5
Log Pow
0.73
2.34
2.77
5.18
3.15
0.04
1.83
4.90
2.35
3.39
0.59
1.46
1.39
0.76
2.37
3.15
0.67
1.69
2.15
5.52
         134

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TABLE D-l (Continued)
Substance Name
PENTACHLOROETHANE
PENTACHLORONITROBENZENE/QUINTOZENE/
PENTACHLOROPHENOL
PENTANE /BPA/
PENTANOL
PHENANTHRENE
PHENOL
PHENOL , 4 - CHLORO , 3 -METHYL
PHENOXYACETIC ACID ,2,4, 5 -TRI CHLORO
PHENOXYACETIC ACID , 2 , 4 - DICHLORO
PHENTERMINE
PHENYLARSONIC ACID /PKA2-8 . 48/
PHENYLMERCURIC ACETATE
PHENYLTHIOUREA
PHORATE/THIMET/
PHOSPHINE SULFIDE,TRIS-(1-AZIRIDINYL)/NSC 639
PHOSPHORIC ACID
PHTHALIC ANHYDRIDE
PIPERAZINE
PROARGYL ALCOHOL/2 - PROPYN - 1 - OL/
CAS Number
76-01-7
82-68-8
87-86-5
109-66-0
71-41-0
85-01-8
108-95-2
59-50-7
93-76-5
94-75-7
122-09-8
98-05-5
62-38-4
103-85-5
298-02-2
52-24-4
7664-38-2
85-44-9
110-85-0
107-19-7
Log Pow
3.05
4.22
5.01
3.23
1.40
4.46
1.48
3.10
3.13
2.81
1.90
0.06
0.71
0.73
3.56
0.53
-1.86
1.60
-1.17
-0.38
          135

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TABLE D-l (Continued)
Substance Name
PROPANOL
PROPENAL/ACROLEIN/
PROPIONALDEHYDE
PROPIONIC ACID
PROPIONITRILE
PROPYLAMINE
PROPYLENE /BPA/
PROPYLENE OXIDE
PYRENE
PYRIDINE
QUINOLINE
QUINONE
STYRENE
TEREPHTHALIC ACID
TETRACHLOROETHYLENE
TETRAFLUOROMETHANE /BPA/
TETRAHYDROFURAN /BPA/
THIOPHENOL
THIOUREA
TOLUENE
CAS Number
71-23-8
107-02-8
123-38-6
79-09-4
107-12-0
107-10-8
115-07-1
75-56-9
129-00-0
110-86-1
91-22-5
106-51-4
100-42-5
100-21-0
127-18-4
75-73-0
109-99-9
108-98-5
62-56-6
108-88-3
Log Pow
0.30
-0.01
0.59
0.33
0.16
0.48
1.77
0.03
4.88
0.62
2.02
0.20
2.95
2.00
3.40
1.18
0.46
2.52
-0.98
2.69
          136

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TABLE D-l (Continued)
Substance Name
TRICHLOROETHYLENE
TRICHLOROFLUOROMETHANE/FREON-11/BPA/
TRIETHYLAMINE
TRIETHYLPHOSPHATE
TRIFLURALIN
TRIMETHYL ORTHOFORMATE
TRIS- (2 , 3-DIBROMOPROPYL) -PHOSPHATE
UREA
VINYL ACETATE
WARFARIN
CAS Number
79-01-6
75-69-4
121-44-8
78-40-0
1582-09-8
149-73-5
126-72-7
57-13-6
108-05-4
81-81-2
Log Pow
2.29
2.53
1.44
0.80
3.06
0.25
3.71
-1.09
0.73
0.05
          137

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                                  TABLE D-2

   LOGARITHM N-OCTANOL-WATER COEFFICIENTS (LOG POW) FOR SELECTED ORGANIC
            SUBSTANCES  FOUND AT NATIONAL PRIORITIES LIST SITES
  Substance Name
Log Pow
Source
Acenaphthalene
B enz ( A) an. thr acene
Benzo(B)fluoranthene
Benzo(K)fluoranthene
1,12-Benzoperylene
Creosote (coal tar)
Chrysene
Dibenz(A,H)acridine
m-Dlchlorobenzene
Beta hexachlorocyclohexane (Beta BHC)
Delta hexachlorocyclohexane (Delta BHC)
3-Methylcholanthrene
1-Methylphenanthrene
Methylnaphthalene
Napthol
2-Pentanone (Methyl propyl ketone)
2,3-Phenylene pyrene
1,2,3,4-Tetrachlorobenzene
Trlbromomethane (Bromoform)
Trimethyl benzene
2,3,4-Trinitrotoluene (TNT)
2,4,5-Trlnitrotoluene (TNT)
  3.74     U.S. EPA, 1981
  5.61     U.S. EPA, 1981
  6.06     U.S. EPA, 1981
  6.06     U.S. EPA, 1981
  6.51     U.S. EPA, 1981
  3.98     Callahan et al., 1979
  4.98     Leo et al., 1971
  5.73     U.S. EPA, 1981
  3.44     Veith et al., 1980
  3.80     Callahan et al., 1979
  4.14     Callahan et al., 1979
  6.97     U.S. EPA, 1981
  5.00     U.S. EPA, 1981
  4.22     MITRE*
  2.84     Leo et al., 1971
  0.84     MITRE*
  6.51     U.S. EPA, 1981
  4.60     Chiou, 1985
  2.39     MITRE*
  4.04     MITRE*
  2.01     MITRE*
  2.01     MITRE*
*Calculated by Leo's Fragment Constant Method  as  specified in Lyman et al.,
 1982.
                                    138

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                             APPENDIX E

        THE SELECTION OF METHODOLOGY IN ESTIMATING PARTITION
                        COEFFICIENT OF METALS
     The HydroQual analysis of field data  (Delos et al., 1984)

indicated the absence of pH effect on sorption of priority metals on

natural sorbent in surface water.  This finding is contrary to a

wealth of literature which documents the importance of pH on

sorption in surface water.

     Since first noted by Kurbatov et al.  (1951), the importance of

pH effect on sorption has been progressively recognized.  In fact,

pH is generally considered the master variable that governs the

extent of inorganic sorption  (Schindler, 1981).

     Percent cation and anion adsorption on metal oxides (Dzombak

and Morel, 1985; Leckie et al., 1980; and Benjamin and Leckie, 1981)

and metal adsorption on organics have all been found to strongly

depend on pH.  Recall that the partition coefficient (K ) is

defined as:

     K  _  F _ Solute adsorbed per unit mass or solid
      p    C         Solute remaining in solution

                  Percent adsorbed     /      f onnA\~l
              = ,	—-=	   s (mass of solid;
                (100 percent adsorbed)

At a fixed mass of, solids, the increase of the percent adsorption

increases the partition coefficient and the decrease of the percent

adsorption decreases the partition coefficient.  Therefore, the pH

effect on the percent adsorption should manifest itself on the

partition coefficient.  However, when the field data were analyzed


                                139

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by HydroQual, no consistent relationship was found between pH and

the partition coefficient.

     One plausible cause for the absence of pH effect in the field

data is the presence of organic substance (Morel, 1983).  The

presence of natural organic compounds has been suggested to

increase, decrease, or not affect the sorption of metal oxide.  In

the absence of sufficient information to predict the effect of

natural organic material on the sorption of metal ions in natural

water, one may consider the data of Davis (1983) on the sorption of

copper on o-Al.O, (Figure E-l).

     In the figure, the percent adsorption of copper on alpha-

aluminum oxide is shown for two cases—with and without the presence

of dissolved organic carbon (DOC).  The dissolved organic carbon was

extracted from the surface sediment of Lake Urnersee, Switzerland.

In the absence of dissolved organic carbon, the percent copper

adsorbed is characteristic of the cation adsorption on metal oxide—

increasing drastically from 0 percent at pH 4.5 to 70 percent at

pH 7.  In the presence of 4.7 mg/1 dissolved organic carbon, the pH

adsorption edge* moves to the left.  The percent copper adsorbed

increases from 0 percent at pH 3 to 50 percent at pH 5.5 and

decreases slightly to 40 percent for the pH range of 5.5 to 8.
*The absorption of cations generally increases from nearly 0 to
 100 percent over a narrow pH range (1 to 2 pH units).  The curve
 which shows the dramatic increase of adsorption percentage over the
 critical pH range is called the "pH adsorption edge."
                                 140

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%Cu (II)
Adsorbed
100


 90


 80


 70


 60


 50


 40


 30


 20


 10


  0
          3.5
                5 x 10~7 M Cu(ll)
                50mg/l 7-AI2O3
                0.01 M NaCI
                 DOC Added
                Oo
                Q 4.7 mg/l
                                                I
         4.0
4.5
5.0
5.5
6.0    6.5

    pH
7.0
7.5
8.0
8.5
9.0
          Source: Davis, 1983.
                                       FIGURE E-1
                 ADSORPTION OF COPPER ON ALUMINA IN THE PRESENCE
                             OF NATURAL ORGANIC MATTER
                                       141

-------
     The comparison of the two cases indicates that at low pH (i.e.,


pH less than or equal to 6), the organic matter increases the copper


adsorption while at higher pH (pH greater than 6), it decreases the


copper adsorption.  The net result is a flattening of the adsorption


curve over the pH range of 5 to 8.  If the percent adsorption is


fairly consistent over the range of pH 5 to 8, so is the partition


coefficient.  Therefore, the presence of organic matter in the


natural water may be the cause for the lack of pH effect in the


field data analysis.


     The gap between the experimental results (of metal sorption on


metal oxides) and their application to natural systems is suggested


by the aforementioned difference between the experimental results


and field data.  Most of the experimental studies are on sorption on


metal oxides in the absence of organic matter.  Although metal


oxides are important natural sorbents, bare oxide surfaces (i.e.,


hydrated and hydrolyzed but not coated with organic matter) probably


are not the principal sorption sites (Morel, 1983).  There is


increasing evidence indicating that organic surfaces, either as


coatings on inorganic particles or as organic matter itself, provide

                                                         _2
most of the sorption sites.  Bare metal oxides except SiO»  are


positively charged near neutral pH (Stumm and Morgan, 1981).


Therefore, the predominance of organic surface is supported by


recent studies indicating that almost all particles in natural


aquatic systems are negatively charged (Davis and Gloor, 1981, and
                                 142

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Hunter and Liss, 1979).  High surface coverages of organic matter




have been demonstrated for iron oxydroxides precipitated in-situ in




lake water (Tipping, 1981).  Hunter  (1980) suggested that the




adsorbed organic material could mask the properties of the




underlying solid.  However, at present much less is known about




adsorption on organic surfaces than  on metal oxide, and to




extrapolate the result from adsorption on metal oxide to account for




the effect of organic surface coating presents considerable




difficulty.




     In this study,  the HydroQual's  result is used because of the




possible lag between the development of theoretical sorption models




from laboratory studies and their application to natural systems.




The HydroQual's result, which indicates that the partition




coefficient is affected only by the  suspended solid concentration,




is also used as a  screening procedure for metals in rivers and




streams (Mills et  al., 1985).
                                 143

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                             APPENDIX F

               TIME OF TRAVEL IN STREAMS AND RIVERS OF
                      THE SURFACE WATER PATHWAY

     The time of travel between two locations in surface water is an

important consideration in evaluating the importance of decay

processes when the decay rates of a substance are known.  For

example, if travel time is one day, decay processes with a kinetic

rate of less than 0.1 day   are rather unimportant because they

only induce less than 10 percent* concentration difference between

the two locations.  In contrast, if the travel time is 20 days, the

process with a kinetic rate of 0.1 day becomes an important

attenuation mechanism because more than 85 percent of the substance

is lost by the time it reaches the downstream location.

     Therefore, before proposing a scheme for ranking the

persistence of hazardous organic substances in the surface water

environment, it is necessary to define a time scale of concern.

     The time scale of concern is not explicitly defined in the

HRS.  Nonetheless, an estimate of the time scale may be made based

on the target distance scale specified in the HRS.  In evaluating

the targets for the surface water pathway, the HRS currently uses a

three mile target distance limit.  Distance is measured in stream

miles from the probable point of entry of released substance or from

the most downstream point of measured contamination.  The time of


*Percent loss = (1 -  (exp  [-(decay rate) x  (travel  time)])) x  100%.
                                 145

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travel may then be determined as three miles divided by the stream




velocity.




     A three-mile distance corresponds to a relatively short travel




time in most surface water environments.  Salomons and Forstner,




(1981) estimate that surface water flow velocity ranges from 101 to




103 cm/sec (0.23 to 23 mph).  This suggests a travel time for three




miles ranging from 0.005 to 0.5 days.  Table F-l summarizes the




results of several Time of Travel studies conducted by the




U.S. Geological Survey.  The flow velocity ranges from 0.16 mph for




the Ohio River from Pittsburgh to Bellaire during a low flow period




to 6 mph in several streams in the Williamette River Basin, Oregon,




during high flow periods.  This range of 0.16 to 6 mph flow




velocities corresponds to a range of travel time of 0.021 to




0.78 days for a three-mile distance.  Simons (1971) reports that the




U.S. Geological Survey tabulated 2,950 point velocity measurements




and found that fewer than one percent of the measurements exceeded




13 fps (8.9 mph), and that the mean velocity was 4.84 fps




(3.3 mph).  The median velocity corresponds to a three-mile travel




time of 0.05 days; it is 0.04 days for the mean velocity.




     Based on the information available, 0.1 day is selected as the




representative three-mile travel time in streams and rivers.  The




short travel time for streams and rivers clearly suggests that only




substances with half-lives much shorter than one day will experience




significant decay while traveling a distance of three miles.
                                 146

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                         TABLE F-l




SUMMARY OF TIME OF TRAVEL STUDIES BY U.S. GEOLOGICAL SURVEY
Name of River
Great Miami River
Potomac River
Middle Patuxent River
Little Patuxent River
Patuxent River
Mississippi River



Missouri River
Reach
Dayton to Cleveland, Ohio
Ohio (71.3 miles)
Cumberland, MD to
Washington, DC
(186.1 miles)



Baton Rouge to Plaquemine, LA
Plaquemine to Sunshine
Bridge, LA
Sunshine Bridge to Reserve,
LA
Reserve to New Orleans, LA
Yankton, SD to St. Louis,
MO
Flood Conditions
During the Study
Low stream flow
discharge
(550 cfs In July)
Low flow with 99.9%
exceed ence
High flow with 0.3X
exceedence







Flow in the river is
fairly uniform
Velocity (mob) References
0.28 Bauer, 1968
0.51 Searcy and Davis, 1961
3.4
0.74 Crooks et al., 1967
0.90
0.70
1.44 Stewart, 1967
1.36
1.40
1.24
1.68 - 3.35 Bowie and Petri, 1969
1.34 - 2.32

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                                                        TABLE F-l  (Concluded)
             Same of River
                                          Reach
                               Flood Conditions
                               During  the Study
                        Velocity  (mph)
                                                                                                             References
00
           Streams in the
           Williamette River
           Basin, Oregon:

             Subreach discharge
             for Williamette and
             Williamette Rivers

             Middle Santiam River
             South Santiam River
           Ohio River
Pittsburgh to Bellaire
(96.4 miles)
                                   Bellaire to Parkersburg
                                   (88.0 miles)
                                   Parkersburg to Huntington
                                   (127.2 miles)
                                   Huntington to Cincinnati
                                   (158.4 miles)
                              Low flow                  0.4
                              High                     6.0
Low flow                  0.2
High flow                 6.0

Low flow                  0.2
High flow                 6.0

Low flow discharge        0.16
High flow discharge       3.75
(404,000 cfs)

Low flow discharge        0.27
(5,375 cfs)
High flow discharge       4.8
(482,500 cfs)

Low flow discharge        0.23
(7,175 cfs)
High flow discharge       4.9
(637,500 cfs)

Low flow discharge        0.34
(9,250 cfs)
High flow discharge       4.4
(822,000 cfs)
                                                                        Harris, 1968
Steacy, 1961

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                             APPENDIX G

               METHODOLOGY FOR  CALCULATING HALF-LIVES

     This appendix describes the methodology for calculating the

hydrolysis half-life, the biodegradation half -life, the free-radical

oxidation half -life, the photolysis half -life, and the

volatilization half -life.

G.I  Hydrolysis

     The hydrolysis half-life (t -./jX. is calculated as follows:

     (t1/2)h = 0.693/1^

     where K,  is the hydrolysis rate constant.

     The hydrolysis rate constant K,  includes contributions from

acid-catalyzed hydrolysis, base-catalyzed hydrolysis, and

nucleophilic reaction with water (which is often referred to as

neutral hydrolysis).  The value of K,  is determined as follows

(Lyman et al. , 1982):

     Kh = Ka [H+] + Kn + Kb [OH-]

     where    K^ = Total hydrolysis rate constant, in units of (time)"-'-.
              Ka = Acid hydrolysis rate constant, in units of
                    (M)~l(time)~-l where M is moles per liter.
              Kjj = Base hydrolysis rate constant, in units of
              KQ = Neutral hydrolysis rate constant, in units of
                   (time)"1.
            [H+] = Hydrogen ion concentration, in units of  (M).
           [OH+] = Hydroxyl ion concentration, in units of M.

     Obtain the values of K , K, , and K  from peer-reviewed
                           a   o       n
literature or comprehensive review documents such as Wolfe  (1985),

Mabey et al. (1982), and Mills et al. (1985).  If the hydrolysis rates
                                 149

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are reported for a temperature (T) other than 25°C, multiply the


                                                            T-25
reported rates by a temperature adjustment factor of (1.116)



(Wolfe, 1985).  This temperature adjustment factor will cause the rate



constant to vary by a factor of 3 for each 10°C change in temperature.



     Assume the pH of the water to be in the range of 6 to 9, which



covers most of the pH values in surface water (Britton et al., 1983).



Calculate the value of 1^ at pH 6 (i.e., [H+] = 10~6 M and [OH~] -



10~8 M) and at pH 9 (i.e., [H+] = 10~9 M and [OH~] = 10~5 M).



Select the lower of the two calculated values.   Use this as the value of



the total hydrolysis rate constant K, .



G.2  Biodegradation



     The biodegradation half-life (ti/?)v is calculated as follows:



     (t1/2)b = 0.693/1^



     where K,  is the biodegradation rate constant, in units of



     (time)'1.



     Obtain the value of K,  from peer-reviewed literature or



comprehensive review documents such as Mills et al. (1985).  If the



rate is reported for a temperature (T) other than 25°C, multiply the


                                                           25—T
reported value by a temperature adjustment factor of (1.07)



The value of 1.07 is the mean of the lower range 1.04 and the upper



range 1.095 (Delas et al., 1984).



     In some cases, the biodegradation rate is  specified as a second



order rate constant (e.g., in units of (volume) (cells)



(time)" ), rather than as a first order rate constant (i.e.,  in
                                150

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unit of (time)  ).  When a second order rate constant is



specified, multiply the rate specified by an assumed microorganism



concentration of 10  cells/ml* to obtain the value of K. .



G.3  Free-radical Oxidation



     Oxidation half-life (t, /0)  is calculated as follows:
                           L/ 2. o


     (t1/2)o - 0.693/ko



     where K  is the total oxidation rate constant.
            o


     The total oxidation rate includes contributions from oxidation



by peroxyl radicals, oxidation by singlet oxygen, and oxidation by



other unspecified oxidants.  The total oxidation rate constant is



calculated as follows (Mabey et al., 1982):



     KQ = KRo2 1*0 '] + KlQ2 [102.] + KQX [OX-]





     where KRQ    = Rate constant for oxidation by peroxyl radical (RO •)•



           K10    = Rate constant for oxidation by singlet oxygen (10 •).



                  = Rate constant for oxidation by other oxldants (OX').



           [RO •] = Peroxyl radical concentration.

              2


           [10 •] = Singlet oxygen concentration.

              2


           [OX']  = Other oxldants concentration.



     Obtain the values of K.., Kln, and 1C   from peer-reviewed
                           KU    U       OX


literature or comprehensive review documents such as Mabey et al.


                                                          -9

(1982).  Assume the peroxyl radical concentration to be 10   M and



the singlet oxygen concentration to be 10    M (Mabey et al.,
*This value  is roughly the geometric mean of the cell concentration range

 of 500 to 106 cells/ml for 40 surface waters as reported by Paris et al.

 (1981).


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1982).  Rate constants for oxidation by other oxidants are rarely

available and need not be included unless available.

G.4  Photolysis

     The photolysis half-life (t- ,-)  is calculated as follows:

     (t1/2)p = 0.693/Kp

     where K  is the photolysis rate.

     The photolysis rate K  used in calculating the photolysis

half-life is to be the rate averaged over both a 24-hour day

receiving the mean annual sunlight and the depth of the water body.

     Obtain the value of the photolysis rate from peer-reviewed

literature.  If the reported value is for a mid-day near surface

situation, multiply the value by 2/Tr* to convert from a mid-day to a

daily average value, and then multiply by 1/30** to convert from near

surface to a depth average value.  The value of the photolysis rate

may also be obtained from existing studies that have estimated the

photolysis rate using laboratory data on absorption spectrum and

quantum yield in conjunction with the method specified in Burns

et al. (1982).
 *The ratio of daily average to daily-maximum assuming a half
  sinusoidal distribution of sunlight over the 12-hour day.
**The ratio of near surface rate to a depth average rate for a water
  column of 2 meter depth and light attenuation coefficient  of
  15 m"1.

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G.5  Volatilization

     The volatilization half-life (t/.. ,„)  is calculated as

follows:

     ^1/2^ = °-693/Kv

     where K  = Volatilization rate, in units of (time)"

     Estimate the value of K  using the following equation and

parameter values as presented in ICF (1984):

                       /                                    i
                                                             -1
Kc = 1
v L
[ 1 + RT \
Ko
\
where :
m n
(DC/D°) Hc $ (DC/DW)
11 8 8 8 /

L = Mixing depth of the water body in units of cm; assi
          be 200 cm.

     K^ = Liquid phase mass transport coefficient of oxygen in the
      1   water body in the units of cm hour"1; assumed it to be
          8 cm hour"1 in rivers and 1.8 cm hour"-'- in lakes.

     D^ = Liquid phase diffusion coefficient of the hazardous
      1   substance in water, in units of cm^ sec"1-

     D^ = Liquid phase diffusion coefficient of oxygen in water,
      1   in units of cm^ sec"-'-.

     m  = Coefficient depending on the liquid phase turbulence;
          assume it to be 0.7.

     R  = Gas constant, 62.4 torr ("K)"^"1, or
          8.205 x 10~5 m3 atm ("K)"1 mol"1-

     T  = Temperature in unit of °K; assume it to be 298°K.

     Hc = Henry's constant in unit of torr M"1 or m3 atm mol"1.

     KS = Gas phase transport coefficient for water in units of
          cm hour"1; assume it to be 2,100 cm hour"1.
                                  153

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     D£ = Gas phase diffusion coefficient of the hazardous
          substance in air, in units or cm' sec~l-

     ifd = Gas phase diffusion coefficient of water in air, in
          units of cm^ sec~l.

     n  = Coefficient depending on the gas phase turbulence; assume it
          to be 0.7-

     Obtain the value of Henry's constant from peer-reviewed

literature or comprehensive review documents such as EPA (1985).  The

ratio of the liquid diffusion constants for the hazardous substance

             C  0
and oxygen (D.. /D- ) is related to the ratio of their

molecular weights and is calculated as follows (HydroQual, 1982):

      £
     D         -2/3
     where W^ = Molecular weight of hazardous substance.
           WQ = Molecular weight of oxygen.

     Similarily, the ratio of gas diffusion constants for the
                     C  W
chemical and water (D /D ) is related to the ratio of
                     g  g
their molecular weights and is calculated as follows:
     »;   IV        I18,
     where Wy = Molecular weight of water.
                                154

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                             APPENDIX H

                              GLOSSARY
Advection

Biodegradation




First-order Kinetics
Movement of substance by current.

Enzyme-mediated reaction, primarily by
the metabolic activities of bacteria and
fungi; the catalyzed reactions include
oxidation, reduction, hydrolysis.

A reaction where the rate of change of a
substance concentration (c) is only
dependent on the substance concentration,
that is:
Free-radical Oxidation
Fully Mixed Tank Reactor
Half-life
Hydraulic Retention
Time
Hydrolysis
                                    dt
where K is a parameter independent of C.

The oxidation reaction between the
substance with free radicals in water;
the free radicals considered in this
study include singlet oxygen and alkyl
peroxyl radical.

A reactor with no concentration gradient
inside the tank and the outflow concentr
ation is the same as that in the reactor.

The time it takes for the concentration
of a substance be reduced to half of its
initial concentration; it is calculated
as 0.693/(decay rate).

The time it takes for an inflow to fill
up a specific volume of water body,
calculated as V/Q where V is the volume
and Q is the flow rate.

Reaction of a chemical with water;
usually resulting in the introduction of
a dydroxyl into a molecule:
                                    R - X + H20
                           -*-ROH, + HX
                                 155

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Hydrophobic

Idealized Water Body
Irreversible process
Photolysis
Polarity
 Priority Metals
Sorption
Steady-state model
Thermocline
Volatilization
Unionized
Nonwater soluble.

A simplified version of the water body
such as that described in the text:  a
stream as a channel with advection as
the dominant transport process and lake
as a fully-mixed reactor.

A reaction which cannot be reversed,
usually proceeds to completion in one
direction.

Photon-activated reaction; molecules
absorb sunlight in ultra violet and
visible portions of the spectrum to gain
sufficient energy to initiate chemical
reaction.

The orientation of a molecule which
cause the separation of the positive
charge nucleus from the negative charged
electron clouds.

Metals on the list of the 129 priority
pollutants designated under the Clear
Water Act, including Sb, As, Be, Cd, Cu,
Pb, Hg, Ni, Se, Ag, Tl and Zn.

A general expression to describe
processes which move a substance from
water to be accumulated in solid; it
includes physical adsorption, chemical
adsorption and ion-exchange.

A mathematical model with describes a
system with constant input and output.

In all lakes of sufficient depth, the
water may be divided into a warm,
turbulent upper region and a cool,
relatively undisturbed lower region.
The plane with maximum rate of decrease
in temperature is defined as thermocline.

Loss of a substance from water to the
atmosphere.

Not ionized; in a nondissociated
molecular form.
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