ENVIRONMENTAL
                                                    PROTECTION
 l-'l'j                                                  AGENCY
EPA-600/3-76-098
August 1976                                    Ecological
                                                     LIBRARY
                      EFFECTS OF  WASTEWATER AND
                  COOLING WATER  CHLORINATION  ON
                                            AQUATIC LIFE
         ,5*-.-.
                                        Environmental Research Laboratory
                                       Office of Research and Development
                                      U.S. Environmental Prelection Agency
                                             Duluth, Minnesota 55804

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                 RESEARCH REPORTING SERIES

Research reports of the Office of Research and Development, U.S. Environmental
Protection Agency, have been grouped  into five series. These five broad
categories were established to facilitate further development and application of
environmental technology. Elimination of traditional grouping was consciously
planned to foster technology transfer and a maximum interface in related fields.
The five series are:

     1.    Environmental Health Effects Research
     2.    Environmental Protection Technology
     3.    Ecological Research
     4.    Environmental Monitoring
     5.    Socioeconomic Environmental Studies

This report has been assigned to the ECOLOGICAL RESEARCH series. This series
describes research on the effects  of pollution on humans, plant and  animal
species, and materials. Problems are assessed for their long-  and short-term
influences.  Investigations include formation, transport, and pathway studies to
determine the fate of pollutants and their effects. This work provides the technical
basis for setting standards to  minimize undesirable changes in living organisms
in the aquatic, terrestrial, and atmospheric environments.
This document is available to the public through the National Technical Informa-
tion Service, Springfield, Virginia 22161.

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                                                   EPA-600/3-76-098
                                                   August 1976
EFFECTS OF WASTEWATER AND COOLING WATER CHLORINATION ON AQUATIC LIFE
                          William A. Brungs
                  Environmental Research Laboratory
                      Duluth, Minnesota  5580U
                  ENVIRONMENTAL RESEARCH LABORATORY
                 OFFICE OF  RESEARCH AND DEVELOPMENT
                U.S. ENVIRONMENTAL PROTECTION AGENCY
                      DULUTH, MINNESOTA  5580^

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                                  DISCLAIMER


    This report has teen reviewed "by the Environments,! Research Laboratory-Duluth,
U.S. Environmental Protection Agency, and approved for publication.  Mention of
trade names or commercial products does not constitute endorsement or recommendation
for use.
                                          11

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                                 FOREWORD
    Our nation's freshwaters are vital for all animals and plants, yet our
diverse uses of water	for recreation, food, energy, transportation, and
industry	physically and chemically alter lakes, rivers, and streams.  Such
alterations threaten terrestrial organisms, as well as those living in water.
The Environmental Research Laboratory in Duluth, Minnesota develops methods,
conducts laboratory and field studies, and extrapolates research findings

    —to determine how physical and chemical pollution affects
      aquatic life

    —to assess the effects of ecosystems on pollutants

    —to predict effects of pollutants on large lakes through
      use of models

    —to measure bioaccumulation of pollutants in aquatic
      organisms that are consumed by other animals, including
      man

    This report summarizes the recent literature on the effects of total
residual chlorine on aquatic life and should be useful to people with interests
in aquatic toxicology and the control and regulation of water pollution.
                                     Donald I. Mount, Ph.D.
                                     Director
                                     Environmental Research Laboratory
                                     Duluth, Minnesota
                                      111

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                                   CONTENTS






                                                                          Page




Acknowledgments	•	,,.vi




I   Introduction  	  ,,,,,.,.,......   1




II  Summary	,,,,,,,   3




III Conclusions	,..,...   4




IV  Recommendations	   5




V   Review of the Literature	   6




        Review Papers	   °




        Chlorinated Municipal Wastewaters	••   7




        Continuously Chlorinated Water  	   9




        Intermittently Chlorinated Water  	  !3




        Dechlorination  	  20




        Avoidance 	  .....  20




        Formation of Chlorinated Organic Compounds	2-L




        Miscellaneous 	  25




        Aquatic Life Criteria and Application Factors ...  	  2°



        Regulations	30




VI  References	32

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                                ACKNOWLEDGMENTS
    This review, like any that attempts to "be current, is greatly dependent  upon
researchers and other interested parties who have permitted the citation of  their
unpublished data and conclusions.  There are many, as the following references
indicate.  These people are to be commended for their concern for this
environmental problem, and I wish to thank them sincerely for their cooperation.
                                       VI

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                                   SECTION I

                                 INTRODUCTION
    In the past few years there has been a great increase in the amount of field
and laboratory research on the effects of wastewater and cooling water chlorination
on aquatic life.  The majority of this research has been on the effects of
intermittent chlorination used in the control of biofouling organisms.  Some data
for intermittent chlorination can be applicable to wastewater chlorination if
they describe relative sensitivity of various aquatic organisms or life stages
of single species.  It is probably valid to assume that these sensitivity
relationships would be comparable for aquatic life under conditions of continuous
exposure, the characteristic of chlorinated municipal wastewaters.

    The increased concern about chlorine toxicity results from three principal
causes:  (a) field observations demonstrating significant areas of biological
degradation; (b) the erroneous impression that total residual chlorine (TRC) is
very rapidly converted to chlorides; and (c) the increasing reliance on discharge-
permit limitations in the National Pollutant Discharge Elimination System of the
U.S. Environmental Protection Agency.  Discharge permits have been influential in
controlling the discharge of TRC from power-generating stations.

    Until recently it was assumed that TRC would not persist in most environments
because of the chlorine demand of the receiving water, which would reduce TRC to
chloride, a relatively nontoxic anion.  Studies have described (l, 2) the rate
of decay of TRC by both dilution and chlorine demand of the receiving stream.
On-site studies at several municipal waste treatment plants were conducted with
plant effluents and stream water.  Concurrent effects of chlorine demand of the
receiving water, dilution, and time were studied.  Dilution ratios of effluent
to receiving water were 1:1, 1:^, and 1:9.  One significant observation of these
studies was that TRC persisted in the diluted wastewater throughout the 3-hr
period.  Also noteworthy was the almost complete lack of chlorine demand of the
receiving water; the major effect on chlorine decay rate was from dilution only.

    An additional problem in wastewater disinfection is that little effort has
been made to optimize the process in existing plants (3).  Personnel engaged in
wastewater treatment have generally attempted to meet increasingly stringent
bacteriological requirements of regulatory agencies by increasing the chlorine
feed rate.  Other changes such as mixing and contact time would require
structural modifications.  The need to optimize the disinfection process so that
the toxic effect on aquatic communities is reduced to a minimum is obvious.
Rising costs for disinfection procedures such as dechlorination may result in
greater efforts toward optimization.  Increasing chlorine feed rates to meet
bacteriological limitations has resulted in maximum TRC values of 5.17 mg/1 in
central Illinois (M, of over 10 mg/1 in southern Wisconsin (5), and as high
as 15 mg/1 in wastewater effluent in California (6).

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    The degree of environmental damage caused "by chlorine has passed relatively
unnoticed for other reasons.  Harr (7) concluded that "chlorination is the most
universally accepted method for the disinfection of wastewater."  When a process
has been as effective in protecting public health as chlorination, many data
are needed to convince managers that it needs reappraisal.

    There is an interesting historical note with regard to the regulation of
chlorine discharges.  In 1868, the Rivers Pollution Commission was appointed in
the United Kingdom to inquire into "the best means of preventing the pollution
of rivers."  A report and conclusions were submitted in 1870 (8) with
recommendations for the Mersey River and Ribble River basins.  The Commission
concluded that "it will be necessary to prescribe definite standards of purity
below which no liquid shall be admissible into any river or stream."  These
standards of purity "have been framed with a due regard to the extent to which
the cleansing of foul liquids can be effected without the imposition of undue
restrictions upon the manufacturer."  Numerical concentration limits were
suggested for a wide variety of materials and conditions.  If these concentration
limits and conditions were exceeded the liquids would be "deemed polluting and
inadmissible into any stream."  For free chlorine the limit for any liquid, after
acidification was 10 mg/1.  The Commission had sufficient insight to believe that
"as science progresses improved methods of purifying polluting liquids will be
discovered, and that eventually standards of purity considerably higher....may,
if necessary, be enforced."

    The following discussion of the biological effects of chlorine is a
continuation of an earlier review by the author (9).  The reader is referred to
that paper for publications before 1973.  The present review is divided into
various sections to permit those readers with only specific interests in
chlorination to find those topics with a minimum of effort.  These sections are:
review papers, chlorinated municipal wastewaters, continuously chlorinated water,
intermittently chlorinated water, dechlorination, avoidance, formation of
chlorinated organic compounds, miscellaneous, aquatic life criteria and application
factors, and regulations.

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                                  SECTION II

                                    SUMMARY


    The literature since 1972 pertaining to waste-water and cooling water chlorination
is discussed under the following headings:  review papers, chlorinated municipal
wastewaters, continuously chlorinated water, intermittently chlorinated water,
dechlorination, avoidance, formation of chlorinated organic compounds, aquatic life
criteria and application factors, and regulations.

    Field and laboratory research results support a single criterion of 0.003 mg/1
for continuous exposure of freshwater organisms.  The former distinction between
warmwater and coldwater systems is no longer appropriate; recent data indicate
that several freshwater fish species are as sensitive as trout and salmon.

    The present concern for the formation of chlorinated organics in water and
wastewaters is justifiable and the greatest present need is to determine the
ecological significance, if any, of these results.  The future course of wastewater
chlorination will be greatly influenced by the recent proposed changes in the
Environmental Protection Agency's regulations on secondary treatment.  The changes
intend that disinfection only be considered when public health hazards need to be
controlled, and that the exclusive use of chlorine should not be considered where
protection of aquatic life is of primary consideration.  Where these uses co-exist,
alternate means of disinfection must be considered.

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                                  SECTION III

                                  CONCLUSIONS


1.  Total residual chlorine (TRC) is acutely lethal to some aquatic organisms
    at concentrations below the usual detectable analytical limit.

2.  The toxicity of TRC in seawater is less clear than in freshwater because of
    the unclear picture of the chemistry of halogens in seawater.

3.  The acute toxicity of TRC in clean water and chlorinated domestic wastewaters
    is generally the same.  This appears to be true of chronic toxicity also.

U.  Dechlorination appears to eliminate the acute and chronic toxicity of TRC to
    aquatic life.

5.  Intermittent chlorination for biofouling control in freshwater can generally
    be significantly reduced with no loss of control.

6.  Several species of freshwater minnows are as sensitive as trout and salmon
    to lethal TRC concentrations.

7.  Most freshwater invertebrates are no more sensitive to TRC than freshwater
    fish.

8.  Avoidance of intermittent chlorination in the laboratory and continuous
    wastewater chlorination in the field has been demonstrated.  The implications
    of the former have not been demonstrated.

9.  Chlorination of water and wastewater results in the formation of chlorinated
    compounds that have been shown to be bioconcentrated by freshwater fish.

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                                  SECTION IV

                                RECOMMENDATIONS


1.  Several important general research needs are evident from this review:

    a)  Halogen chemistry in seawater.

    b)  Chemical and toxicological data on alternatives to disinfection by
        chlorination.

    c)  More sensitive and specific analytical methods for disinfectants.

    d)  Exposure conditions necessary to control various species of biofouling
        organisms.

2.  When disinfection and the protection of aquatic life are both necessary, the
    most feasible alternative at this time would be dechlorination.

3.  The single criterion for continuous exposure of freshwater organisms to TRC
    should be 0.003 mg/1.

h.  The most appropriate criteria for intermittent exposure of aquatic organisms
    to TRC are time dependent.

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                                   SECTION V

                           REVIEW OF THE LITERATURE
REVIEW PAPERS

    Tsai (lO) reviewed the literature on the effects of sewage treatment plant
effluents on fish.  He discussed not only the toxic effects of TRC, but also
the toxic effects of ammonia, synthetic detergents, hydrogen sulfide, sewage
sludge, and dissolved oxygen.  Additional topics of this review included fish
culture in wastewater effluents and toxic flagellates.  One of his more important
observations about chlorine toxicity was that very few studies have been conducted
on the effects of continuous exposure of TRC on estuarine and marine fishes.  This
situation continues to persist; most of the present marine research, to be discussed
later, is oriented to the intermittent effects of power plant chlorination or is
conducted under laboratory conditions with clean dilution water rather than with
chlorinated wastewater effluent itself.

    The literature on the use of calcium hypochlorite in fisheries was summarized
by Podoliak (ll).  His title and discussion suggest a very narrow topic, but his
listing of approximately 1,230 citations would be useful to any generalist or
specialist involved in manufacturing, use, effects, or regulation of chlorine.
Chlorine was used to eradicate unwanted fish UO years ago, but its principal
use in fisheries today is to control or eliminate infectious diseases and
parasites in hatcheries.

    Becker and Thatcher (12) reviewed and tabulated data on the toxicity to
aquatic life of a wide variety of chemical additives, including chlorine and
bromine, that may be used in nuclear power plants.  In tabulating the toxicity
data, they described the chemical compound, test organism, test conditions,
concentrations, and the type of test conducted.

    Whitehouse (13) prepared a review of the literature on chlorination of
cooling water and presented data on the effects of free and combined chlorine
on a wide variety of aquatic organisms.  He concluded that marine and freshwater
species are apparently equally vulnerable to the action of chlorine and that
smaller organisms are affected in shorter exposure times than larger ones.
He concluded that all aquatic organisms are susceptible to chlorine and that
chlorine apparently has a common mode of action on living material, although
certain organisms with specialized tissues such as gills or byssus glands may
not fit this generalization.

    An annotated bibliography was prepared by Mattice and Pfuderer (1*0 that
covers the chemistry and effects of chlorine in aquatic systems.  This
bibliography contains abstracts of 190 papers and reports written during the
past 50 years.  Evins (15) surveyed and summarized published data on the
toxicity of chlorine and chloramines to some freshwater organisms, excluding
bacteria and fungi.  Davis and Middaugh (l6) reviewed the use of chlorine as a

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disinfectant and antifouling chemical in marine ecosystems.  They discussed
briefly the chemistry of chlorine in marine waters with emphasis on the
production of bromine and bromamines by the chlorination of seawater.  They
summarized the toxicity of TRC for phytoplankton, invertebrates, and estuarine
fish.  Brooks and Seegert (17) discussed the various factors such as chemical forms,
time of exposure, and temperature that are important in determining the toxicity of
TRC to aquatic life.  They presented a synthesized view of the toxicity of TRC
as it relates to clean waters and sewage effluents.  The principal differences
in toxicity were due to differences in chlorination, whether intermittent or
continuous, and in experimental temperatures, which covered a wide test range.

    The Atomic Safety and Licensing Board requested a critical review (l8) of
current literature and research on the lethal, sublethal, and behavioral effects
of chlorine and other biocides on aquatic life and on the chemistry and
biochemistry of the products formed following release and degradation of
chlorine in the aquatic environment.  The principal purpose of this review
was to evaluate biofouling control for power-generating stations on the
Columbia River.
CHLORINATED MUNICIPAL WASTEWATERS

    Servizi and Martens (19) placed rainbow trout at various points downstream
from three sites where chlorinated domestic wastewater effluent was being
discharged.  At one site the discharge from a retention lagoon essentially
resulted in a dechlorinated final effluent that was nontoxic to the rainbow
trout.  The test fish died downstream from the other two sites that had no
retention ponds.  During one test period at one of the latter sites the
chlorinator was not operating, and no fish died.  They concluded, in general,
that lethality was common at stations where TRC concentrations were 0.02 mg/1
or greater.

    One hundred forty-nine domestic wastewater treatment plants were studied
in Virginia, Pennsylvania, and Maryland (20).  Fish-community diversity and fish
occurrence were related to observed TRC concentrations.  In most of the plants
studied a TRC concentration of 0.5 to 2.0 mg/1 was maintained in the effluent.
In streams receiving chlorinated effluent no living organisms were observed in
the immediate vicinity of the outfall.  No fish were found in water at TRC
concentrations at or above 0.37 mg/1.  The species diversity index fell to zero
at 0.25 mg/1.  An analysis of Tsai's graphically presented data indicated that
the brown and brook trout did not occur at TRC concentrations above approximately
0.02 mg/1.  Ten fish species, including five minnows, a bullhead, two darters,
and the two trout were not observed at concentrations above 0.05 mg/1.  At 10
facilities with chlorination and an effluent-holding lagoon that resulted in
dechlorination, fish-species diversity did not differ above and below the
outfalls.

    Olson (2l) studied the effect of chlorinated wastes from the Marshalltown
(Iowa) water pollution control plant on native and caged fish in the Iowa River.
The dilution of the effluent during these studies ranged from 25:1 to 282:1.
The observations were made just as the plant began a chlorination program, and
the TRC concentrations determined amperometrically varied from 0.00 to 5.0

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mg/1.  No adverse effects on native fish were observed, and caged channel catfish
did not survive within a distance of 150 ft after 96 hr of exposure.

    Norris et_ a^. (22) discussed ecological investigations of municipal waste
disposal in San Francisco Bay and the Gulf of the Farallones.  Static
bioassays were conducted with a variety of marine and estuarine fish and
invertebrate species.  Continuous-flow bioassays were conducted on Dungeness
crab zoea and three-spined stickleback.  Unfortunately, all of the toxicity
results are expressed as percentage of effluent, and no mention is made of
residual chlorine concentrations.

    During 1973 and 197^ massive fish kills involving bluefish, sea trout,
croaker, menhaden, and others were observed in the James River estuary of
Virginia (23).  Extensive field studies determined that the cause was chlorinated
wastewater discharged to the system by two sewage plants.  Field bioassays
were conducted with bluegill sunfish, and unchlorinated and chlorinated
effluents in the plant confirmed the lethality of the discharge.  When the
chlorination feed was reduced, the fish kill was almost completely eliminated
during the next 2k hr.  This observation was made during both years.  Laboratory
bioassays with a variety of estuarine species provided kQ- and 96-hr LC50
values between 0.005 mg/1 for oyster and clam larvae and 0.28 mg/1 for pipefish.
Details of these studies will be discussed later in this review.

    Unchlorinated sewage was a relatively weak inhibitor of fertilization of
gametes of the sea urchin, Strongylocentrotus purpuratus (2U).  Chlorinated
sewage was more detrimental, and adverse effects were observed at TRC concentrations
as low as 0.05 mg/1.  The principal effect was on sperm.  Fertilization was
also inhibited at 0.20 mg/1 for Urechis caupo and Phragmatopoma californica.
All exposures were for only 5 min.

    Nominal TRC concentrations of 0.02, 0.1, and 3.0 mg/1 for a 1-hr contact
time were evaluated for disinfection capability with primary sewage (25).  An
acceptable MPN (most probable number) was obtained only at 3.0 mg/1, which
nominal concentration was highly toxic to sockeye salmon.  Measured TRC
concentrations varied considerably and ranged from 0.06 to 2.05 mg/1.  Golden
shiners were exposed to chlorinated primary and secondary effluent by Esvelt
et_ all. (26), and continuous-flow, 96-hr LC50 values averaged 0.19 mg/1 with a standard
deviation of 0.08 mg/1.

    Stone et_ al_. (27) reported on studies that focused on the long-term effects
resulting from the discharge of various municipal effluents into the waters
of Central San Francisco Bay.  Central Bay model aufwuchs (represented by
decomposers, producers, and herbivores) were tested with unchlorinated and
chlorinated secondary effluent.  Above U percent effluent the unchlorinated
waste stimulated growth of aufwuchs biomass.  The average TRC concentration was
0.06 mg/1 in the bay model tanks receiving 1 percent effluent; this concentration
reduced biomass accumulation to less than 30 percent of that measured in the
controls.  A reduction in chlorophyll a_ concentration to about 50 percent of the
control was also observed in a 1-percent effluent with a TRC concentration of
0.06 mg/1.  No aufwuchs biomass was found in tanks receiving higher TRC
concentrations.  Golden shiners were also studied; tap water was used for dilution
of the chlorinated primary effluent.  Ninety-six-hr LC50 values ranged from
0.16 to 0.26 mg/1 with a mean of 0.21 mg/1.

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    Chronic, life-cycle toxicity tests with the fathead minnow, a cladoceran
(Daphnia magna), and an amphipod and numerous acute tests with fish and invertebrate
species were conducted by Arthur et_ al. (28).  Non-disinfected, chlorinated,
dechlorinated, and ozonated secondary effluent was used.  The lowest mean TEC
concentrations having a measurable adverse chronic effect were O.OH2 mg/1 for the
fathead minnow, 0.019 mg/1 for the amphipod, and approximately 0.010 mg/1 for
Daphnia magna.  The highest mean TRC concentrations having no measurable effect
were Q.Qlk mg/1 for the fathead minnow, 0.012 mg/1 for the amphipod, and 0.002 to
O.OOU mg/1 for Daphnia magna.  This corresponds to a concentration range of 1.2 to
2.5 percent chlorinated effluent.  One-hr to 7-day LC50 values were determined
for the brook trout, coho salmon, fathead minnow, white sucker, walleye, yellow
perch, largemouth bass, amphipod, stonefly, caddisfly, crayfish, and snails.  The
7-day LC50 values for the fish ranged from 0.082 to 0.26l ing/1.  The invertebrates
were generally more resistant with 7-day LC50 values from 0.21 to >0.8l mg/1.

    Ward et_a^. (29) and Ward (30) discussed a set of toxicity tests nearly comparable
to those of Arthur et^ al_. (28) at the Grandville (Michigan) Wastewater Treatment
Plant, an activated sludge facility receiving wastewater almost totally derived from
domestic sources.  The results of their chronic test with the fathead minnow
were consistent with those of Arthur et_ al_. (28).  The lowest concentration of TRC
that caused an adverse effect was O.OU5 mg/1, at which concentration larval growth
and survival were affected.  A concentration of 0.01 mg/1 was considered safe.
Acute toxicity tests with the fathead minnow, lake trout, goldfish, rainbow trout,
coho salmon, largemouth bass, crappie, an unidentified sunfish, walleye, pugnose
shiner, common shiner, and golden shiner also yielded comparable results to those
of Arthur _e_t al_. (28), with 96-hr LC50 values between 0.0^0 and 0.278 mg/1.  The
LC50 values for the four species of minnows were as low as or lower than those
for the trout and salmon, which would indicate that these warmwater fish species
are as sensitive as the trout and salmon.  The most resistant fish were the sunfish
and largemouth bass.  Chlorobrominated effluent had no chronic effect on fathead
minnows at concentrations of residual bromine at or below 0.0^3 mg/1; 96-hr LC50
values for lU fish species were from O.Okj to 0.283 mg/1 residual bromine.  Fathead
minnows exposed to sublethal concentrations of chlorine and bromine before LC50
tests were more resistant to lethal concentrations than those fish not previously
exposed.  Similar acute and chronic toxicity tests to those described above have
begun at the Wyoming (Michigan) Wastewater Treatment Plant; the influent to this
plant is about equally derived from industrial and municipal operations.

    Primary, secondary, and chlorinated secondary effluents from a municipal
sewage treatment plant were tested to determine their impact on off-flavor in
rainbow trout as determined by the Sensory Evaluation Section of the Department
of Food Science and Technology, Oregon State University (3l).  Only chlorinated
secondary effluent concentrations of 20 percent by volume and above produced
tainted fish.  In one experiment no flavor impairment occurred at 33 percent
by volume, and all fish died at higher concentrations.  The addition of chlorine
to the secondary effluent appeared to reduce the impairment since concentrations
of about 15 percent by volume of unchlorinated primary and secondary effluent
produced an off-flavor.


CONTINUOUSLY CHLORINATED WATER

    Eren and Langer (32) studied the effects of chlorinated water on a mixed
population of two species of tilapia.  Fish kills involving these species had

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been observed in the operational reservoirs of the Israel National Water
System.  An especially severe kill occurred in the Tsalmon Reservoir, and chlorine
was suspected since the channel leading to this reservoir had been previously
chlorinated with measured TRC concentrations up to 0.3 mg/1.  Various laboratory
exposures for k to 18 hr were conducted at different temperatures and ratios of
free and combined chlorine.  The authors concluded that smaller fish were more
sensitive, that fish were more sensitive at the higher test temperatures, and
that free chlorine was more toxic than combined chlorine.

    When a concentration of O.U mg/1 TRC was maintained continuously to eliminate
fouling organisms at a marine power station, productivity of entrained marine
phytoplankton decreased 83 percent (33).  Productivity was measured at six other
continuously applied TRC concentrations, and the lowest concentration tested,
which was below the authors' detectable limit of 0.1 mg/1, caused a decrease of
79 percent in productivity.  When chlorine was not applied during the study period,
phytoplankton productivity was essentially unaffected.

    Gentile et_ al_. (3*0 discussed the results of field and laboratory investigations
on chlorine toxicity to marine organisms related to power plant condenser cleaning.
In the laboratory growth rate of 11 species of phytoplankton decreased 50 percent
during a 2k-hr exposure to TRC concentrations between 0.075 and 0.330 mg/1.
Phytoplankton were also studied at several power-generating stations.  Median
survival times for three species of estuarine copepods ranged from 120 to 360 min
at 1.0 mg/1 to 0.7 to 5 min at a TRC concentration of 10 mg/1.  Two species of
ichthyoplankton (winter and yellowtail flounder) were studied under laboratory
conditions.  The 2^-hr LC50 values for the yellowtail flounder were 0.2 and 0.1
mg/1.  Attempts were made to evaluate these effects in the field.

    The combined effects of chlorine and temperature on rainbow and brook trout
were studied by Wolf et_ aJ^. (35).  Sensitivity of brook trout decreased as size
of the fish increased.  Ninety-six-hr LC50 values as determined in continuous-
exposure tests were between approximately 0.04 and 0.065 mg/1 with a mean of about
0.05.  Thatcher et_ aJ. (36) acclimated brook trout to 10, 15, and 20° C and tested
these fish at 7, 10, 15, and 20° C.  The TRC 96-hr LC50 values from 13 continuous-flow
toxicity tests run at 10 and 15° C were not significantly different regardless of
the previous acclimation temperature.  At 20° C the brook trout were more sensitive.
The mean LC50 values at 10 and 15° C were about 0.15 mg/1; the mean value at 20° C
was about 0.10 mg/1.  Schneider et_ aJ^. (37) cited these same results, but included
data from some interesting studies with crayfish.  The 96-hr LC50 value for
TRC was 0.96 mg/1 and indicated that the crayfish were very resistant.  However,
many crayfish died during the 6-wk period after the exposure ended.  When the LC50
was recalculated to take these deaths into account, the value became 0.25 mg/1.

    Warren (38) exposed several fish species and crayfish to chloramines and
determined acute and subacute effects on growth and survival.  Alkalinity
and pH were varied, but over the experimental range (pH, 7-5 to 8.1; alkalinity,
lUO to 320 mg/l) the 96-hr LC50 values for cutthroat trout and coho salmon did
not vary significantly (0.078 to 0.089 mg/l).  Ninety-six-hr LC50 values for
brook trout ranging in age between 8 and 60 weeks were between 0.082 and 0.091
mg/l, which indicated no influence of age on sensitivity, a result different
from that of Wolf et_ al_. (35).  Growth, food consumption, or food-conversion
efficiency at different feeding levels of coho salmon juveniles were not affected
by exposure to TRC concentrations of 0.005 and 0.010 mg/l.  Fish exposed to
0.020 mg/l chloramines had significantly lower growth, food consumption, and
                                          10

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food-conversion efficiency.  Residual chlorine had no apparent effect on the
fertilization process (artificial), embryo survival, time of hatching, or alevin
mortality at TRC concentrations (only during fertilization) as high as 0.39** mg/1-
Results of partial chronic tests with crayfish indicated mortality at a
chloramine concentration as low as 0.100 mg/1 and at 0.050 mg/1 egg clusters
carried "by female crayfish contained few, if any, live embryos.  The control
and 0.025 mg/1 exposures showed no effects on the embryos.  Additional studies on
laboratory streams are continuing.

    Blacknose dace were exposed (39) to both free chlorine and chloramine
concentrations for several periods of time to determine survival times after short
exposure and subsequent return to chlorine-free water and lethal exposure times.
The need for determining both types of results became apparent when the authors
observed dead fish among the fish returned to clean water after brief exposures
to chlorine.  At higher test concentrations free chlorine was more toxic than
chloramines, but it was less toxic at lower concentrations.

    Bluegill and channel catfish were exposed to chloramines under continuous-
flow conditions by Roseboom and Richey (ho),  Different temperatures and fish
sizes were compared.  The 96-hr LC50 values for the more resistant bluegill
ranged from 0.18 to 0.33 mg/1.  The authors indicated that the smaller bluegills
were more sensitive and that chloramine was more toxic at a higher temperature.
The estimated 96-hr LC50 for the channel catfish was about 0.09 mg/1, and
temperature did not appear to influence the sensitivity of this fish species.

    Carlson (Ul) exposed mature threespine sticklebacks to chloramine concentrations
of 0.001, O.OOU3, and O.OUA mg/1 for 3.5 months to observe their reproductive
behavior under laboratory conditions simulating their natural environment.
Isopod and amphipod populations were included in the test chambers as a
partial food source for the sticklebacks.  By the end of the test no differences
in reproductive behavior of the fish could be observed at any.of the measured
chloramine concentrations.  In addition, no differences were detectable
in the standing crops of amphipods (Crangonyx sp.) or isopods between the control
and experimental chambers.  Early in the study the growth of periphyton on the
chamber walls was delayed at the tested concentrations as compared to the controls.
Estimates of periphyton standing crop at the end of the test reflected a trend
of decreasing biomass with increasing chloramine concentrations; effects were
observed at all tested concentrations.

    Eggs and larvae of plaice, a flatfish, were continuously exposed to TRC
concentrations at test temperatures of 5.U to 9.3° C (^2).  The 3-day and 8-day
LC50 values for eggs were 0.7 and 0.12 mg/1, respectively.  Ninety-six-hr LC50
values for the larvae were 0.02^, 0.028, and 0.03U mg/1.  The egg membrane
appeared to give considerable protec-t^Lon to the embryo, allowing development
to continue normally over long periods, even in TRC concentrations that would
be rapidly lethal to the hatched larvae.  Hughes (k3) used reconstituted
water and acute, static bioassay methods to determine the sensitivity of
striped bass larvae and 1-month-old striped bass fingerlings to 30 chemicals
including chlorine.  Nearly all the observed deaths due to chlorine occurred
within 2k hr; the 96-hr LC50 values for larvae and fingerlings were 0.5 and
0.25 mg/1.
                                         11

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    The toxicity of TRC to Juvenile spot in flowing seawater was studied by
Middaugh et_ al_. (kk) .  Incipient lethal concentrations were determined, and
avoidance tests were conducted.  Histopathological changes and the combined
effect of thermal stress were also determined.  After continuous exposure for
up to 8 days, the incipient LC50 values for TRC were 0.12 mg/1 at 10° C and 0.06
mg/1 at 15° C.  Pseudobranch and gill damage was indicated at a measured TRC
concentration of 1.57 mg/1; no consistent tissue damage was detectable after
exposure to 0.02 to 0.62 mg/1.  Avoidance also appeared to be temperature
dependent with avoidance to a TRC concentration of O.l8 mg/1 at 10° C.  At
15 and 20° C the spot avoided concentrations as low as 0.05 mg/1.  After
exposure to 15, 20, 25, and 28° C for 7.5, 15, 30, and 60 min, a significant
increase in sensitivity was detectable related to increased temperature and
exposure time.
                                                 *
    Gregg (1*5) described studies with a variety of aquatic invertebrate species
exposed continuously and intermittently at different temperatures to TRC.
He also conducted heat-shock and chlorine-plus-heat-shock studies to simulate
conditions to which organisms entrained in cooling waters are exposed.  Median
survival times and concentrations were determined; carbon-filtered tap
water was used for dilution.  Temperature exerted an influence on chlorine
toxicity, although the degree of effect varied with different species and for
some no temperature effect was detected.  Mayflies, stoneflies, sowbugs, amphipods,
caddisflies, water pennies  (beetle), and snails were tested.  The LC50 values
for continuous exposures were intermediate between the LC50 values for
intermittent exposures based on maximum or peak concentrations and mean
concentrations.  Extreme differences in chlorine sensitivity were found among
the species tested, even among the mayfly species.  The majority of the k- and
7-day LC50 values for continuous exposure to TRC were between 0.010 and 0.10 mg/1.
Since some of these tests were conducted at nearly lethal temperatures, some
instances of high control mortality may have been due to heat.
    The rotifer, Keratella cochlearis, was continuously exposed by Grossnickle
to concentrations of TRC for periods of 1, U, and 2k hr.  Any longer exposure
would have been over 10 percent of the average life span of this species.  Only
the most resistant individuals could survive concentrations of 0.055 mg/1 or above
at any of the exposure times; control mortality was 0 to 12 percent.  The 1-, k-,
and 24-hr LC50 values were 0.032, 0.027, and 0.0135 mg/1, respectively.

    Several invertebrate estuarine species were exposed to various TRC concentrations
by Roberts et_ al . (47) under continuous- flow, continuous-exposure conditions for up
to 96 hr.  The 48-hr LC50 for the copepod, Acartia tonsa, was less than 0.05 mg/1,
the minimum detectable TRC concentration in this study.  Larvae of the clam,
Mercenaria mercenaria, and oyster, Crassostrea virginica, demonstrated 48-hr LC50
values of less than 0.005 mg/1.  The 96-hr LC50 for the glass shrimp, Palaemonetes
pugio, was 0.22 mg/1.  Of the three fish species tested, the pipefish was the most
tolerant with a 96-hr LC50 of 0.28 mg/1.  The 96-hr LC50 values for silversides
and naked gobies were 0.037 and 0.08 mg/1, respectively.  The authors used
amperometric titration and could not detect monochloramine ; they assumed that only
free chlorine was present in all experiments.  Bender et al. (48) also discussed
these results on estuarine fish and invertebrates, but included a brief discussion
of the uptake of carbon by four species of algae.  Hannochloris occulatus,
Tetraselmia suecica, Pseudoisochrysis paradoxa , and Pyramimonas virginica
in unialgal cultures and natural mixed populations were exposed to various
TRC concentrations.  The algae in monospecific cultures were tested at three
                                          12

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salinities and three temperatures in pasteurized river water.  Carbon uptake
rates were measured with a U-hr incubation period.  More details of the
methods have been discussed  (^9).  Results expressed in relation to the
control values and EC50 values ranged from approximately 0.01 to O.UT mg/1
depending upon species, temperature, and salinity.

    Gibson et al. (50) conducted preliminary toxicity tests and growth rate
experiments with the coon stripe shrimp, Pandalus danae, to determine LC50
values for temperature, chlorine, and copper, and the sublethal effects of these
factors on growth rate.  Shrimp were acclimated at 8 and 15° C and exposed
for 96 hr to TRC at test temperatures of 10, 15, and 20° C.  The shrimp were
most resistant when acclimated and exposed at the lowest test temperature; the
96-hr LC50 values were 0.26  to 0.36 mg/1.  They were less resistant when
acclimated at the low temperature and tested at the two higher temperatures;
the 96-hr LC50 values were between approximately 0.11 and 0.19 mg/1.
Intermediate results, 96-hr  LC50 values between 0.15 to 0.21 mg/1, were
obtained for those shrimp acclimated to and tested at 15° C, which was near
the shrimps' optimum short-term growth temperature of l6° C.  A TRC concentration
of O.l8 mg/1 was lethal to young shrimp at l6° C, and 0.08 mg/1 reduced their
growth over a 1-month period.

    Beeton et_ al_. (5l) exposed freshwater copepods and rotifers to continuous
concentrations of TRC.  The  copepod Cyclops bicuspidatus thomasi was quite
sensitive with a 96-hr LC50  of 0.08k mg/1 as monochloramine.  The 96-hr
LC50 for this same species was 0.069 mg/1 when the TRC was a mixture of
hypochlorite and monochloramine.  The ^-hr LC50 values for the rotifer
Keratella cochlearis was 0.019 mg/1.

    Sodium hypochlorite was  added by Sanders et_ al_. (52) to hatchery water in
experiments to evaluate its  ability to control the infectious protozoan,
Ceratomyxa shasta.  Chlorination and filtration apparently inactivated infectious
organisms when TRC ranged from 2.2 to 5.3 mg/1.  Granular activated carbon was
used to dechlorinate the hatchery water after a 60-min contact time.

    The effect of free chlorine and chloramine on the uptake of nitrate and
ammonia by freshwater phytoplankton was studied by Toetz et_ ajU (53).  Free
chlorine and chloramine were added to bottled lake water in concentrations that
ranged from 0.01 to 0.1 mg/1.  These bottles were incubated for about 2k hr after
which uptake was determined.  These single doses of chlorine reduced nitrate uptake
by phytoplankton at a concentration as low as 0.028 mg/1.


INTERMITTENTLY CHLORINATED WATER

    The following studies evaluating the impact of intermittent chlorination on
freshwater and marine organisms are most applicable to cooling waters.  As
discussed earlier, however,  some of the data are useful also for the evaluation
of chlorinated municipal wastewaters.  Any adverse concentrations observed
would obviously be adverse under continuous-exposure conditions.  The relative
sensitivity of species, or life stages of a species, intermittently exposed may
be the same under continuous-exposure conditions, that is, a species very
sensitive, or very resistant, under the intermittent-exposure conditions
could be expected to respond similarly to conditions comparable to those found in
chlorinated wastewaters.
                                        13

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    Chlorination of cooling water to retard growth of fouling organisms was
first tried in the United States in 192U.  All but about 10 percent of the
electric generating plants chlorinate on a programmed basis.  Exceptions are
those plants using cooling water that contains sufficient suspended solids to
physically scour the condenser tubes.  The total amount of chlorine used for
this purpose is currently about 100,000 tons per year (5*0.

    Cole (55) summarized chlorination practices used to control^biofouling in
freshwater and seawater systems and under once-through and recirculating
conditions.  He believed that there is a tendency for operators to overchlorinate
because of the difficulty in determining the required chlorination schedule.
The author concluded that it appeared reasonable to expect that heat exchangers
can be maintained in a clean condition using less chlorine than has been used
in the past, since minimization programs have resulted in reductions in the duration
of chlorination periods, frequency of chlorination, and chlorine feed rates.
Draley (56) discussed biofouling control in cooling towers and closed cycle systems
in general and specifically at a nuclear power station with a mechanical draft
cooling tower and a coal-fired plant with a natural draft cooling tower.  He was
concerned principally in describing the buildup and decay of chlorine in these
systems.  Monitoring of residual chlorine in effluents for compliance with discharge
regulations and the necessity of using continuous recorders was discussed by
Baker (57).  The levels at which these analyzers are required to operate approach
the precision and sensitivity of the methods used to calibrate them.  Practical
problems associated with operation and maintenance of continuous recorders under
normal municipal-industrial conditions would, at present, limit the lowest
practical level that can be recorded with assurance to about 0.1 mg/1.

    Mattice and Zittel (58) critically summarized the experimental and analytical
methodology used to develop the data in the literature on chlorine toxicity to
aquatic organisms.  Available data for freshwater and marine organisms were
summarized, and acute and chronic toxicity thresholds were approximated that
would result in no toxicity.  Log TRC concentrations versus log time plots
demonstrated different acute and chronic thresholds for freshwater and marine
species.  The chronic toxicity threshold for fresh water was 0.0015 mg/1 and
that for salt water was 0.02 mg/1.  The freshwater organisms appeared to be
more sensitive to chronic exposure, but marine organisms appeared more susceptible
to acute doses of TRC.  The authors used these thresholds to develop a site-
specific procedure for evaluating chlorination schemes at power plants.  An
analysis of a hypothetical marine-based power plant was presented to demonstrate
the procedural steps involved.  The analysis was based on comparison of the
concentrations and exposure times expected at this hypothetical plant and the
toxicity threshold developed for marine organisms.  Additional examples of a
hypothetical marine power plant have also been discussed in a summary of the
above predictive site-specific analysis by Mattice (59) in which he compared a
single plant with three possible dilution rates.

    Brungs  (60) reviewed the literature relating to condenser antifouling and
discussed the possible additive effect of other stresses such as supersaturation,
temperature, diseases, and parasites.  This review included a brief discussion
of needed research on antifouling control and its effects.

    Dickson et_ al_. (6l) conducted an in situ toxicity test in the Clinch River
(Tennessee) to evaluate the effects of intermittently chlorinated cooling
tower blowdown.  Bluegills and snails were placed in cages at various
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distances downstream from the plant that was treating the cooling towers
four times a day at 0.75 mg/1 for 30 min.  The free chlorine concentration
ranged from 0 to 88 percent (0 to 0.35 mg/l) of the TRC at the point of
discharge; the mean was IT. 3 percent (0.08 mg/l).  The highest observed free
chlorine and TRC concentrations in the river were 0.07 and 0.35 rag/1, respectively.
Wo bluegill deaths could be attributed to chlorine, but the blowdown was lethal
to 50 percent of the snails in 72 hr when exposed to TRC at 0.0*t mg/l for
less than 2 hr per day.  Copper concentrations at this station were as high as
0.08 mg/l and may have affected the results with the snails.

    Basch and Truchan  (62) and Truchan (63) have described field studies conducted
at five power-generating stations in Michigan.  Caged brown trout were held for
96 hr in the intake and discharge channels.  Most chlorinations were for
30 min.  Intermittent concentrations of TRC of O.Ik to 0.17 and O.l8 to 0.19
mg/l for two and four 30-min chlorinations, respectively, were lethal to 50 percent
of the trout in 1*8 hr.  In 96 hr, 50 percent of the trout were killed at TRC
concentrations of 0.02 to 0.05 and 0.17 and O.l8 mg/l for three and six 30-min
chlorinations, respectively.  Caged brown bullheads, fathead minnows, and
various species of sunfish were not killed at these same concentrations.
Underwater observations of resident fish in distress were made at two plants
at concentrations ranging from 0.2 to 0.5
    Marcy (6*0 in his study of vulnerability and survival of Connecticut
River fish entrained at a power plant, observed no deaths due to chlorination.
He concluded that, since only one-fourth of the system was chlorinated at a
time, the resultant dilution and additional chlorine demand lowered the TRC
concentration below an effect level.  The residual chlorine was recorded at
less than 0.1 mg/l.

    Biological studies at the Quad-Cities Nuclear Power Station (65) resulted
in the conclusion that the periodic concentrations of chlorine in the heated
effluent appeared to have a more significant impact on the biotic communities
in the Mississippi than the increased water temperature.  Productivity of
periphytic algae was reduced at times downstream from the plant.

    Fox and Moyer (66) determined in situ productivity in the discharge to the
Gulf of Mexico by the fossil-fueled Crystal River plant.  Primary production
was decreased an average of 57 percent by plant passage and chlorination.
In the absence of chlorine the average decrease was 13 percent.  Each of eight
intake pipes was chlorinated to a TRC concentration of 0.1 to 1.0 mg/l with
dilution by unchlorinated water from the other seven units.  Consequently, TRC
was never detected (limit was 0.01 mg/l) at the discharge where productivity
was reduced.

    Polgar et_ aj^. (67) described a model for entrainment loss of zooplankton
in a power-generating station in the lower Potomac River.  Experimental data
on zooplankton (^6) were compared with the results of this model.   This
comparison showed that radical depletions in the population of copepodite and
naupliar stages occurred that could not be accounted for by cooling system
or delayed entrainment deaths .

    The effect on yellow perch, coho salmon, rainbow trout, alewife, and
spottail shiner of a single 30-min exposure to various concentrations of TRC
                                        15

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was evaluated by Seegert et_ al_. (68).  After exposure the fish were placed in
unchlorinated water and observed for as long as hQ hr.  The LC50 values for
yellow perch tested at 10, 15, and 20° C were 7.7, ^.0, and 1.1 mg/1, respectively.
All other species were tested only at 10° C, and they were all more sensitive
than the yellow perch.  The LC50 value for coho salmon was 1.25 mg/1; for rainbow
trout, 2.0 mg/1; for alewife, 2.25 mg/1; and for spottail shiner, 3.2 mg/1.  Later
studies (69) resulted in LC50 values for alewife at 15, 20, and 25° C of 2.3,
1.65, and 0.92 mg/1, respectively.  For coho salmon, the LC50 values at 15 and
20° C were 1.35 and 0.92 mg/1, respectively.  Additional tests with yellow perch
at 25° C provided an LC50 of 1.0 mg/1 and with rainbow trout at 15° C the LC50
value was 0.9 mg/1.  Delayed mortalities occurred in most of the exposures and
in the tests with the alewife 1J5-95 percent of the TRC was free chlorine.  Yellow
perch and rainbow trout were also exposed for a single 5-min period.  Only one
yellow perch out of 100 was killed at TRC concentrations between 9 and 27 rag/1;
only two out of 130 rainbow trout were killed at concentrations from 1.5 to U.O
mg/1.  Brooks and Seegert (70) exposed rainbow trout and yellow perch to three
5-min doses of TRC separated by 3-hr recovery periods and observed their survival
for hQ to 72 hr.  At 10° C the LC50 value for the rainbow trout was 2.87 mg/1
and for the yellow perch at 10° C the LC50 value was 22.6 mg/1 as TRC.  Mortalities
were delayed for both species usually occurring 2 to 2U hr after the third
exposure.

    Bass and Heath (71, 72), Bass et^ al_. (73), and Bass (7^) exposed rainbow trout
to intermittent chlorinations three times per day.  Breathing, coughing frequency,
and heart beat were measured.  During each chlorination blood p02, pH, and heart
rate decreased, whereas breathing and coughing rates increased.  Increased mucus
production and damage to respiratory epithelium were apparent in histological
sections of gill tissue.  The authors concluded that the primary mode of action
of chlorine is through gill damage leading to death by asphyxiation.  Bass and
Heath (75) and Heath  (76) also exposed bluegills to intermittent chlorinations
simulating the operation of steam electric generating plants.  Small bluegills
were exposed to four concentrations of TRC (0.21 to 0.52 mg/1) at four
temperatures (6 to 32° C).  No deaths occurred at 0.21 mg/1 at any temperature,
and only a few deaths occurred at 0.31 mg/1.  A concentration of 0.52 mg/1
caused 50 percent mortality in less than 75 hr; high temperatures resulted
in more rapid death.

    Warren, in addition to the continuous exposures discussed earlier (38), also
has begun studies on intermittent chlorination with predominantly  free chlorine
and cutthroat trout.  In preliminary experiments single 15- to 60-min exposures
resulted in few deaths at TRC concentrations up to 1.0 mg/1.

    Dickson and Cairns (77) conducted 7^ static bioassays with goldfish at
different exposure times  (15 min to 2h hr), exposure frequencies (one to six times),
chlorine species (free and combined chlorine), sizes of test fish, and temperatures
(a range of 12.5 to 16.5° C and a range of 17 to 22.5° C).  Temperature and size
of fish had no detectable effect on toxicity.  When the concentration of TRC and
the duration of an exposure were held constant, a doubling of the frequency of
exposure from one to two increased the predicted fish mortality by a factor of 8.
Combined chlorine appeared in these tests to be slightly more toxic than free
chlorine.  The TRC continuous-exposure 2l|-hr LC50 for the goldfish was 0.27 mg/1.
The authors concluded that a chlorination protocol of two to three exposures of
                                        16

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15 to 30 min per day with a TRC concentration of 0.5 to 0.75 mg/1 would not
be acutely lethal to fish equally as sensitive as or less sensitive than the
goldfish.  Unfortunately, as indicated elsewhere in this review, the goldfish is
one of the fish species more resistant to TRC.

    Collins (78) exposed emerald shiners to single, 30-min doses of TRC and
observed their behavior and survival for 96 hr.  At 10 and 25° C the LC50 values
for juveniles were approximately 1.1* and 0.3 mg/1, respectively.  He also observed
that the juveniles were less sensitive than the adults at 10° C.

    Stober and Hanson (79) exposed juvenile Chinook salmon to five TRC
concentrations in sea water at four temperatures and four exposure times between
7.5 and 60 min.  Juvenile pink salmon were tested at three temperatures.  Dynamics
of chlorine decay in sea water were also discussed.  A decrease in the tolerance
of both species was demonstrated with increasing temperature and exposure
time.  Mean times to equilibrium loss and death were presented.  The result
of studies with fluctuating TRC concentrations during a 2-hr chlorination
under continuous-flow conditions with juvenile pink salmon was an LC50 value
of O.Ql*5 mg/1; under these conditions, the time for 50 percent of the test
fish to die occurred in about 100 min at approximately 0.5 mg/1.

    The interaction of temperature shock and up to 10-min exposures to TRC
concentrations in sea water of 0.3 to 0.5 mg/1 was studied by Hoss et_ aJ^. (80).
Larval flounder exposed to 0.3 nig/1 with no temperature shock survived for
up to 5 min, but after 7 min the exposure mortality was 20 percent, and after
10 min mortality was 100 percent.  At 0.3 mg/1 there was no loss of larval
menhaden after 7 min when there was no temperature shock.  At 0.5 mg/1 the
mortality of these fish was 100 percent after 10 min.  Between 1*0 and 60
percent of juvenile mullet died when exposed to 0.3 mg/1 for 7 to 10 min
with no thermal shock.  When these three fish species were subjected to shock
temperature increases of as much as 12° C, their chlorine sensitivity increased
greatly, indicating at least an additive effect of the two stresses.

    Margrey et al. (8l) exposed Atlantic menhaden and hogchoker to concentrations
of chlorine between 0.125 and 2.0 mg/1 under continuous and intermittent exposure
conditions for 96 hr or until 100 percent mortality occurred.  The Atlantic
menhaden was the more sensitive species and, in general, the fish survived longer
when exposed intermittently rather than continuously.

    Early developmental stages of plaice and Dover sole were exposed under
continuous-flow conditions to TRC in sea water by Alderson (82).  The eggs of
plaice were most resistant with 72- to 192-hr LC50 values of 0.6k and 0.105
mg/1, respectively.  The early larval stages of both fish species were most
sensitive with 1*8- to 96-hr LC50 values between 0.025 and 0.071 mg/1.  Metamorphosed
fish were of intermediate sensitivity with 96-hr LC50 values for TRC between
0.070 and 0.095 mg/1.  No attempt was made to differentiate between the effects
of the various chlorine and bromine compounds produced as a result of sea-
water chlorination.  The author concluded that in sea water the TRC probably
consisted mainly of bromine compounds.

    Nash (83) has presented some of the problems and uses of condenser cooling
water for fish farms.  Specific problems resulting from chlorination of these
waters are discussed in relation to water chemistry.
                                         17

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    The effects of intermittent chlorination on marine and freshwater
invertebrates are less well understood than the effects on fish.  McLean C8U)
exposed colonies of hydroids attached to suspended nylon lines to TRC concentrations
of 1.0 to U.5 mg/1 for 1 and 3 hr and then returned the colonies to their
natural habitat.  Differences in exposure time caused no significant difference
in new growth.  The percentage of new growth was slightly lower in colonies subjected
to concentrations of 2.5 to 3,5 mg/1 than in the controls,  McLean (85) also
exposed barnacle larvae, copepods, grass shrimp, and two species of amphipods to
TRC in the laboratory in continuous-flow test chambers.  Most of the exposures
were for 5 min to a TRC concentration of 2.5 mg/l» after which the test organisms
were transferred to chlorine-free water for observation.  Average mortality was
80 percent for barnacle larvae and 90 percent for copepods exposed for 5 min.
Mortality was low in the shrimp and amphipods exposed to TRC for 5 min.  When the
exposure time for these two species was increased to 3 hr, mortality of one
amphipod species immediately after the 3-hr exposure was about 25 percent and
after 96 hr mortality was 97.2 percent.  Shrimp deaths were comparable after the
3-hr exposure, and almost all were dead at 96 hr.

    Acute bioassays were conducted (86) to determine the effect of thermal
shock and chlorine exposure on the estuarine copepod, Acartia tonsa.
Laboratory conditions simulated power plant operation with an 8° C thermal
shock and brief chlorinations.  A single dose of chlorine was added to static
test chambers, and after 96 hr a TRC concentration of 0.75 mg/1 measured at
the start of the test was fatal to 30 percent of the copepods.  At 1.15 mg/1
all copepods died.  Latimer (87) and Latimer et al. (88) exposed two species of
freshwater copepods to 30-min chlorinations at several temperatures.  Based on
the added chlorine and the ammonia content of the test water, the authors expected
that the resulting TRC would be predominantly free chlorine.  As temperature
increased over the range of 10 to 20° C, sensitivity also increased, and the
30-min LC50 values for Cyclops bicuspidatus thomasi decreased from lU.68 to 5«76
mg/1.  The 30-min LC50 values for Limnocalanus macrurus at 5 and 10° C were both
1.5^ mg/1.  The two species had entirely different regression slopes.  Cyclops
was able to withstand a much wider range of TRC concentrations than was
Limnocalanus.  Twenty-five percent of Cyclops died at concentrations below 5 ng/l»
whereas 25 percent were able to survive a concentration of 1*5 mg/1.

    Protozoan communities were exposed to free chlorine three times in a 2-hr
period by Cairns and Plafkin  (89).  The number of species (relative to controls)
decreased significantly at concentrations above 1.15 mg/1.  Free chlorine
concentrations above 0.66 mg/1, when added every 20 min over the 2-hr period,
caused a significant decrease in the number of species surviving.  Certain species
appeared to be more tolerant of the chlorine stress, and these  species were among
those previously known to be tolerant of other stress conditions.  In these
experiments an increase in the number of chlorine additions over the 2-hr period
effectively lowered the concentration that produced a significant reduction in species
diversity.  Changes in species numbers or species diversity were not different from
those expected as purely additive effects,

    Ginn et_ a!L.  (90) studied the survival of estuarine amphipods entrained
in condenser  cooling water from the Hudson River.  Mean survival at
the intake and discharge stations with no chlorination ranged from 90 to 99
percent; during  chlorination mean survival at the two discharge stations ranged
from 51 to 8l percent.  Data on TRC concentrations were not presented.
                                           18

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    Davies and Jensen (91) examined quantitatively the entrainment of zooplankton
at representative thermal power plants operating in a once-through mode on a
river, lake, and estuary.  Thermal and chlorination effects were both evaluated.
The TRC concentrations between 0,25 and 0.75 mg/1 at the Indian River plant
(estuarine) did not reduce the zooplankton motility ratio by more than 50
percent.  In two of three instances when chlorine levels of 1,00 mg/1 were measured
at the Indian River plant and when concentrations from 0.50 to 5-0 mg/1 were
recorded at the Chesterfield Plant (river), the zooplankton motility ratio was
reduced by 85 to 100 percent.  The plant sited on a freshwater lake used
mechanical cleaning instead of chlorination.

    Stage I larvae of the American lobster  (less than 48 hr old) were exposed
by Capuzzo et al. (92) to 30- and 60-min exposures at three temperatures to free
and combined chlorine in sea water filtered through activated charcoal to remove
dissolved organics and a 1-y filter to remove particulates.  The larvae were
observed during a 48-hr period.  Applied chloramine was more toxic than
corresponding concentrations of applied free chlorine with estimated LC50
values at 25° C of l6.3 mg/1 (applied concentration of free chlorine) and 2.02
mg/1  (applied concentration of chloramine),  Toxicity was reduced at 20° C and
increased at 30° C.  Approximately 18 percent of the applied concentration of
free  chlorine and chloramine was detectable, amperometrically, as residual
chlorine.  No reason for this low recovery  in filtered sea water was determined.
Respiration rates of the lobster larvae were reduced even 48 hr after the short
exposure periods at all tested concentrations.  Similar results were obtained at
0.05 mg/1 applied chloramine and 0.10 mg/1  applied free chlorine.

    One significant problem in antifouling  control is the significant lack of
experimental data with which to determine the actual need for chlorination in
terms of frequency and duration of use and  the times of years when antifouling
is necessary.  It is readily apparent that  in many cases chlorine is used in
great excess.  For example, during 1973 to  1975 Commonwealth Edison Company
(with plants on and around Lake Michigan) has achieved a system-wide 30 percent
net reduction in chlorine use (93).  This reduction represented a savings of 1.5
million pounds of chlorine in this one system.

    Carpenter and Macalady (94) discussed the ability of various analytical
methods for the determination of residual chlorine in sea water.  They concluded
that present methods do not appear to be satisfactory if close compliance with
regulatory statutes involves analysis of samples from wastewater treatment plants
and electric generating stations.  They attribute this problem to the lack of
understanding of exactly what occurs when sea water is chlorinated, and this
knowledge of the chemical species is a prerequisite to designing proper
analytical methods,

    Eppley et_ al. (95) studied the decline  in free and residual chlorine in
filtered, non-filtered, and ultraviolet-oxidized sea water.  In the filtered
and non-filtered samples there was a rapid  initial decline followed by a slower
decline; no decline was observed in the ultraviolet-oxidized sample probably
because of removal of those molecular species that react with chlorine.  In
addition, they observed decreases in marine phytoplankton photosynthesis after
intermittent exposure to power plant chlorination as low as 0.01 mg/1 of TRC.
The authors discussed the analytical problems unique to sea water as influenced
                                        19

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by bromine and the formation of residual bromide after the initial formation of
hypobromous acid and hyprobromite.  They suggest that differences between toxicity
between freshwater and marine situations might reflect differences in the toxicity
of residual chlorine vs. residual bromine.
DECHLORINAT10N

    Many of the above recent toxicity studies have also evaluated the use
of dechlorination for the elimination of TRC toxicity by using a variety of
chemicals and procedures such as lagooning of wastewater (19» 20), sodium
bisulfite (26, 27), sulfur dioxide (28, 29), sodium sulfite  (U6, 51), activated
carbon (52), and sodium thiosulfate (2U, 62, 63).  Tsai (10) included a brief
summary of several studies that involved dechlorination of wastewaters.  Carbon
filtration alone may not always reduce TRC to acceptable levels for toxicity
testing (1*5).

    Martens and Servizi (96) studied the influence of dechlorination of primary
sewage with sulfur dioxide on toxicity, pH, and dissolved oxygen.  The pH and
dissolved oxygen were the same whether or not dechlorination was used.  In
addition to the elimination of chlorine toxicity, the toxicity of the chlorinated-
dechlorinated primary effluent was less than the toxicity of untreated primary
effluent, suggesting degradation of some toxic constituents by the chlorination-
dechlorination treatment of primary effluent.  No acute effects of a mean
sulfur dioxide residual of 2,20 mg/1 were detectable after 96 hr.  When the study
plant (Lulu Island Treatment Plant) reaches the design flow of 16 mgd, the cost of
dechlorination is estimated to be about one-third the cost of disinfection
with chlorine.

    Photochemical action for the removal of free chlorine from water before its use
in fish tanks has been discussed by Armstrong and Scott (97).  Commercial mercury-
lamp water sterilizers can be used.  The treated water appeared to be harmless to
fish.

    Shifrer et_ al_. (98) evaluated the toxicity of the effluent from a small
physical-chemical waste treatment system at a Utah highway rest station.
Sodium sulfite was used to eliminate TRC toxicity so that less toxic components
of the effluent could be evaluated.
AVOIDANCE

    This interesting phenomenon has been  studied to only  a  slight degree
recently.  Meldrim  et_ al_.  (99) determined behavioral avoidance responses to
temperature and  chlorine under various conditions of salinity, light, and
dissolved  oxygen concentration over the annual range of temperature  in the
Delaware River estuary.  Responses to various TRC concentrations were determined
for the white perch, mummichog, hogchoker, grass shrimp,  sand shrimp, and blue
crab.  Measurements of free  and combined  chlorine indicated that most of the TRC
was free chlorine.  Results  of multiple regression analysis indicated that only
                                         20

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the bluecrab preferred potentially lethal concentrations.  In addition, avoidance
concentrations were generally inversely related to temperature and to light level.

    Bogardus et_ al. (100) described a new avoidance test chamber and determined
the avoidance responses of the mimic shiner, river shiner, and the bullhead
minnow.  The system was buffered to pH 8.6 with an excess of ammonium chloride
to ensure that monochloramine was the principal component of TRC in this study.
Test concentrations were analyzed amperometrically and ranged from 0.005 to
0.5 mg/1.  Each group of fish was exposed to a low concentration, and if no
response was detected, the concentration was raised to the next level.  The
procedure was continued until avoidance was observed.  The mimic shiner was the
most sensitive and was able to detect and avoid all tested concentrations between
0.005 and 0.^5 mg/1.  River shiners avoided test solutions when the monochloramine
concentration reached 0.15 mg/1.  The avoidance-inducing concentration for the
bullhead minnow was between 0.03 and 0.05 mg/1.  Even after the test ended and
no TRC could be detected, the mimic shiner still avoided entering the effluent
side of the test chamber.  Observations for up to 30 min indicated that this
minnow had learned to avoid the toxicant side of the chamber.  At higher
concentrations the avoidance reaction was so great that even when the observer
placed his hands in the chamber, the fish could not be driven into the toxicant
side.

    The study by Tsai (20) previously described was not designed to detect or
observe avoidance, but the study did relate the presence and absence of 1*5 fish
species in relation to measured TRC concentrations.  Unless there were
additive or synergistic effects of TRC and such factors as ammonia concentration,
turbidity, detergents, or other major components of domestic wastewaters, it
may be that Tsai (20) was actually observing avoidance.  Tsai and Fava (101)
and Fava and Tsai (102, 103) studied the avoidance of chlorinated sewage effluent,
chloramine solutions, and free chlorine solutions by the blacknose dace, a small
minnow.  The fish avoided a TRC concentration of 0.51 mg/1. after 20-min exposures
to the chloramine solutions and to the chlorinated sewage.  The avoidance
concentration for free chlorine was 0.92 mg/1.   The threshold avoidance
concentrations, indicating an initial slight response to TRC, were 0.13, 0.18,
and 0.6l mg/1 for chlorinated sewage, chloramine, and free chlorine, respectively.
When the exposure time was increased to 220 min the fish avoided all the chloramine
and free chlorine solutions at concentrations as low as 0.07 mg/1.  Unchlorinated
sewage effluents were not avoided.  The authors also observed that some fish
definitely preferred concentrations of free chlorine at 0.52 and 0.19 mg/1
after a 20-min exposure.   The authors concluded that chloramines are the major
constituents in chlorinated sewage effluents causing fish to avoid these effluents
and that this avoidance response explains the absence of fish in streams below
outfalls when there is no evidence of fish kills.
FORMATION OF CHLORINATED ORGANIC COMPOUNDS

    Among the factors contributing to the present concern for the potential
environmental impact of wastewater chlorination is the formation of chlorine-
containing organic constituents in chlorinated effluents.  Jolley (lOU, 105)
described a method to study this potential problem by combining radioactive
tracer chlorination in the laboratory with high-resolution chromatography.   Using
this procedure he detected over kQ chlorine-containing compounds in primary
domestic effluent.  Subsequent studies (106) dealt with secondary effluent.  These
                                        21

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studies also attempted to estimate the concentrations of the chlorine-containing
compounds.  The qualitative results with secondary effluent were comparable to
those with primary effluent (105).  The actual concentrations of these compounds
ranged from 0.00021* to O.OOU3 mg/1.  Jolley et al. (10?) have described their
analytical procedures in detail.

    Glaze et_ al. (108) studied secondary effluent before and after laboratory
chlorination for 1 hr and have presented some preliminary results.  Mass
spectroscopy and mass spectroscopy-gas chromatography were used after neutral
organic constituents were concentrated by adsorption on resin.  The gas
chromatography studies with a Coulson detector demonstrated concentrations of
chlorine compounds in the range of 0.001 to 0.05 mg/1 in the wastewater effluent.
Only a few of the compounds the authors observed were identified, but chloroform
was positively identified.  In addition, Glaze and Henderson (109) and Glaze
et_ al. (110) collected grab samples of secondary municipal effluent, and
superchlorinated them (> 1,000 mg/l) with a contact time of 1 hr.  Organics were
resin-extracted and analyzed.  Qualitative and quantitative results were obtained
for a few dozen chemicals with most concentrations in the range of 0.010 to O.OHO
mg/1.  The highest concentration detected was 0.285 mg/1 for 3-chloro-2-methylbut-l-ene.

    Jolley et al. (ill) have also studied the formation of chloro-organics by
chlorination of cooling waters.  Cooling water was chlorinated in the
laboratory for 75 min at 2.0 mg/1.  Over 50 chlorine-containing organic
compounds were found.  They estimated that several hundred tons of chlorinated
organics are produced annually in the United States by this antifouling process.
The concentrations of chloro-organic products formed during chlorination of
cooling waters and process effluents were estimated by Jolley et_ al_ . (112).
Concentrations ranged from 0.0002 to 0.02 mg/1 for phenols, purines , aromatic acids,
pyrimidine, and nucleoside.

    The ability of natural humic substances to act as precursors for haloform
production during chlorination of natural waters was studied by Rook (113).  Four
haloforms were clearly recognized; these were chloroform, dichlorobromomethane,
chlorodibromomethane, and bromoform.  Further experimentation with a non-polluted
natural water taken from a lake in a peaty region provided the same result;
chloroform production attained a concentration of 0.2 mg/1.  An unexplained
phenomenon was the formation of bromohaloforms in proportions much greater than
the ratio of added chlorine to bromine concentrations in the river water.
    A report by Carlson et_ a.1. (llH) dealt with the aqueous chlorination of
aromatic systems and the examination of the relationship of chlorine incorporation
to pH and contact time.  The extent of chlorine incorporation into the biphenyl
nucleus (chlorobiphenyl production) was pH dependent, and above pH U extended
reaction times were required to observe extensive chlorine incorporation.
The ability of the relatively unactivated biphenyl nucleus to be chlorinated
under a wide range of aqueous chlorination conditions, plus the facile
chlorination of those compounds (phenols and aromatic ethers) that resemble a
variety of naturally occurring compounds , suggests that many chlorinated organics
could be produced in this manner.

    Carlson and Caple (115, 116) found that chlorine reacted readily in an aqueous
medium with a variety of compounds (a-terpineol, oleic acid, abietic acid,
cholesterol, etc.) that are known to be present in wastewaters subjected to
                                           22

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chlorine-renovation processes.  Biological effects on Daphnia magna, a.
cladoceran, of the compounds formed by chlorine incorporation were also examined.
Toxicity generally increased with increasing chlorine content.  The effects
of chlorination on "biological oxygen demand (BOD) were examined by comparing
the BOD requirements of a sample containing a given chemical system with that
of its chlorinated products.  The results indicated that the chlorinated material
is generally degraded to a lesser degree than the parent compound and that the
lowered BOD values appear, at least -in the case of phenols, to be due to the
increased toxicity of the chlorinated material to the degrading species.

    The study of chloro-organic formation has also extended into the area of
biological studies.  Kopperman et^ aU (117) have studied the residues accumulated
by fish exposed to chlorinated secondary wastewater for their entire life cycle
through reproduction.  The exposure tests with these fish were described
earlier (29).  By using gel permeation chromatography for tissue cleanup and
gas chromatography-mass spectroscopy techniques for identification, various
compounds were identified that were either not present in fish reared in non-
disinfected effluent or were present in much lesser quantities.  Some of these
compounds were di- and tri-chlorophenol, di- and tri-chlorobenzenes, and
trichloroanisole.  Tribromoanisole was tentatively identified in fish raised in
chlorobrominated effluent.  The principal concern about these chloro-organics
as they relate to fish residue is that the incorporation of chlorine into an
organic molecule increases its lipophilic character, which usually results in
increased toxicity and bioaccumulation.

    Fourteen industrial organic chemicals were studied during biological
wastewater treatment in semi-continuous activated sludge systems (ll8).  The
ability of these chemicals to combine with free chlorine was then determined.
Five of the initial compounds combined readily with chlorine under conditions
commonly used in effluent chlorination.  The ability of these compounds
(phenol, m-cresol, hydroquinone, aniline, and dimethylamine) to react with
chlorine can be related to the structural characteristics of the chemicals.
Several of the reaction products were examined in respirometer studies and
found to be resistant to degradation by a heterogenous microbial population.
In addition, static 96-hr bioassay tests with the fathead minnow were
conducted to determine the toxicity of five reaction products.  The range in
LC50 values was from 0.01 to 10 mg/1.  Continuous-flow aquaria with a
plant-animal ecosystem were also tested with trichlorophenol, benzoquinone, and
trichloroaniline.

    The formation of chlorinted compounds during wastewater chlorination
is not unique.  Unbleached pulp typically becomes fully bleached in a process
that involves one or more chlorinations with hypochlorite and chlorine dioxide
(119).  The toxicity of five compounds, separated in a pure state from the effluent,
was determined with rainbow trout and static bioassay procedures.  The TRC
after the chlorination stage was 50 to 130 mg/1.  The compounds and their
96-hr LC50 values were:  3,^,5-trichloroguaiacol, 0.75 mg/1; 3,^,5,6-
tetrachloroguaiacol, 0.32 mg/1; monochlorodehydroabietic acid, 0.6 mg/1;
dichlorodehydroabietic acid, 0.6 mg/1; and 9, 10-epoxystearic acid, 1.5 mg/1.
These same compounds were found in effluents collected from six other kraft mills.

    Gehrs et al. (120) studied the toxicity to carp eggs of two reaction products
of wastwater chlorination:  U-chlororesorcinol and 5-chloroura.cil.  Eggs
that were water-hardened before exposure were more resistant to these
                                         23

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chemicals than were non-water-hardened eggs.  Both reaction products reduced
hatchability at nominal concentrations as low as 0,001 mg/l.  Subsequent studies
(121) with 5-chlorouracil have been conducted to study its sublethal effect on
carp.  Kine replicated concentrations (0.001 to 10 mg/l) were tested; solutions
were changed twice daily during the 3-day incubation period before hatching.
The effect end point was the percentage of larvae that were malformed just after
hatching occurred.  The percentage of malformed carp larvae increased with
increasing concentrations of 5-chlorouracil above 0,5 mg/1.

    Kopperman et^ al^. (122) determined the toxicity to Daphnia magna of 1^ phenolic
compounds having the ability to incorporate chlorine over a wide range of pH
and concentration.  Toxicity increased significantly with increased halogen content.

    Katz and Cohen  (123, 12U) tested several classes of common compounds before
and after excessive chlorination (5 to 10 mg/l) to determine whether such
treatment would affect the toxicity of those compounds.  Mosquitofish was the
test fish for the static bioassays.  The toxicity of phenol and tryptophan was
increased by chlorination, whereas the toxicity of tannic acid was decreased.
Chlorination had no influence on most of the tested compounds, which included urea,
ornithine, histidine, uracil, linear alkene sulfonate, leucine, and others.

    Morris (125) concluded that the reactions of aqueous chlorine in water
chlorination are not indiscriminate and unpredictable.  In fact, they follow
quite well-defined pathways in accord with general principles of organic reaction
mechanisms.  He added that it is generally possible to predict something of the
nature and extent of the reactions of aqueous chlorine with components of water
and wastewater.

    The Conference on the Environmental Impact of Water Chlorination was held at
the Oak Ridge National Laboratory, Oak Ridge, Tennessee, October 22-2U, 1975.
The major objective of its program was to present and discuss the best available
data concerning the formation and effects of chlorinated organic compounds
associated with the use of chlorine as a biocide or in process treatment.
Three major technical sessions dealt with the aqueous chemistry of chlorine,
biomedical effects of chloro-organics, and environmental transport and effects.
Several presented papers are discussed in this review and the proceedings of this
conference will be published.

    The chlorination of municipal water supplies, although not directly appropriate
to this review since such water has no contact with aquatic life, does result in the
formation of chlorinated organic compounds.  Such information is useful to those
concerned with this problem in sanitary wastewaters and cooling waters and will
be discussed briefly.  Morris and McKay (126) have critically reviewed the
available literature on formation of halogenated organic compounds during the
chlorination of water supplies.  They concluded that chlorination is not
indiscriminate and  does not lead to the formation of a wide variety of chlorinated
derivatives with any and all organic pollutants.  Chlorination results in a
limited number of well-defined reactions on a few specific types of organic
structures.  The identifiable initial reactions are electrophilic aromatic
substitution of positive chlorine and electrophilic addition of positive chlorine
to appropriately activated double bonds.

-------
    Volatile organics were collected from New Orleans drinking water and pooled
human blood plasma by Dowty et_ al. (127).  Using gas chromatography and mass
spectrometry, they identified 13 halogenated hydrocarbons in the drinking water
and five in the blood plasma.  Tetrachloroethylene and chloroform were found in both
plasma and water.  The relative concentrations of the halogenated hydrocarbons in
the drinking water varied considerably from day to day.  The gas chromatographic
procedures used for this study have been described (128).  Additional studies by
Dowty et_ al. (129) have identified approximately TO organic constituents in
finished water, the preponderence of which are either aromatic or halogenated
aliphatic and aromatic.  The authors noted that essentially every compound
observed in finished water was present, usually in a much lower quantity, in the
precursor river water.  They assumed that trace quantities of such compounds may
have originated from wastewater treatment plant discharges upstream.

    Stevens et al. (130) studied the halogenation of organic compounds during
chlorination of drinking water.  The major known products of these reactions
are trihalomethanes.  Several factors influence production of these compounds;
they are precursor compound concentration, pH, type of disinfectant used
(free or combined chlorine), and temperature.  In addition, the point of
chlorination in the treatment process is also a significant factor in
trihalomethane production.  The latter is the most important variable that
could be used to reduce the concentrations of these chlorinated compounds in
drinking water.


MISCELLANEOUS

    In reality, chlorine is a pesticide and it is used principally to control a
variety of human pests (bacteria, slimes, algae, setting organisms, and viruses).
The old adage "If a little will do it, a lot will do it better" applies to
chlorine use just as it does to pesticide use.  Although the usual desired TRC
concentration at the discharge is 0.5 to 2.0 mg/1, concentrations frequently
exceed those necessary for microbiological control.  Snoeyink and Markus (U)
measured TRC below 20 wastewater treatment plants in central Illinois and
determined that monochloramine was the predominant species and that free chlorine
concentrations generally were very small.  The TRC concentrations were as high as
5.17 mg/1 in grab samples.  The authors' measured concentrations were in general
much higher than the values reported by the treatment plant personnel, who used
the orthotolidine method.  Most of the plants used chlorination equipment that
added chlorine at continuous rates regardless of chlorine demand or wastewater
flow through the plant.  This procedure would obviously result in overchlorination
at any times other than the maximum daily loading.  McKersie (5) found concentrations
as high as 10.3 mg/1 in effluent from 22 wastewater treatment plants in southern
Wisconsin.  Simultaneous testing with an amperometric titrator and the chlorine
comparators used by the plant operators showed consistent inaccuracy with the
colorimetric comparators.  As in the Illinois plants, the chlorinators at most of
the Wisconsin plants studied were set at one rate for each 2k-hr period.  As
expected, the TRC concentrations increased with decreasing wastewater flow.

    It is very likely that if chlorinators were operated automatically by
chlorine demand or a monitored TRC concentration in the discharge, the
reduction in the amount of chlorine used would be significant economically as well as
environmentally.  This reduction would eliminate much of the TRC discharged to
surface waters.
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    Pereira et_ al_. (131) developed a predictive model for free residual chlorine
concentrations.  The model considers hydrodynamic transport, chlorine-demanding
reactions, and gaseous exchange with the atmosphere in a flowing stream.
Draley (132) measured free chlorine and TRC in the circulating-water system of a power
plant cooling tower.  For a typical chlorination period the concentration of
free chlorine at the condenser was about 0.1 mg/1 whereas the TRC concentration
reached a maximum of 0.63 mg/1 at the condenser discharge.  More than 2 hr
elapsed, after the addition of chlorine was stopped, before TRC was no
longer detectable (about 0.01 to 0.02 mg/l).  The data for the buildup of
TRC were fitted with a kinetic expression.  Good fits, with reasonable values
for the constants, indicated that the model was correct.  A model for gradual
decay of combined chlorine also appeared reasonable in that, again, good fits
for the data occurred.  Lietzke (133) reviewed the literature to obtain available
kinetic and thermodynamic data on the various chemical reactions of chlorine in
order to develop a model for predicting the composition of chlorinated water
discharged from power plant cooling systems.  Future refinements of this
model will incorporate temperature-dependent expressions for the various
rate and equilibrium constants.

    Nelson (13U) also developed and analyzed a mathematical model to predict
TRC in cooling tower blowdown at any time during the chlorination cycle.  The
model and its eight variations were useful in predicting TRC concentrations in the
blowdown.  The model also permitted alterations in existing chlorination
schedules, which minimized chlorine waste and reduced chlorine concentrations
in the blowdown.  As a result of concentration of dissolved materials in power
plant blowdown, the amperometric titration method had interferences (135).  The
addition of sodium pyrophosphate as a complexing agent removed those interferences
caused by iron and copper in the water matrix.

    Marinenko  (136) and Marinenko et_ aJu  (l3T) developed a new monitor for the
National Bureau of Standards to detect low concentrations of TRC.  Iodine, which
results from oxidation of potassium iodide by TRC, was measured amperometrically
in a system in which coulometrically generated iodine is used as a system
calibrant.  Laboratory and field tests with this monitor and other instruments
were performed for intercomparison.  The portable monitor was capable of measuring
TRC concentrations as low as 0.001 to 0.003 mg/1.

    Johnson (138) expressed concern about the inability to selectively measure the
various species of chlorine in order to minimize the concentration of chlorine
necessary to produce a microbiologically acceptable water.  He compared present
field, laboratory, and continuous methods for free and combined chlorine residual
for specificity, reagent stability, accuracy, and simplicity.  These methods were
the acid orthotolidine methods, DPD, SNORT, LCV, FACTS, amperometric titration,
copper-gold amperometric cells, and the NBS flux monitor.  He also evaluated a
new analytical method specific for HOC1 or NH2C1 in the presence of the poor
disinfectants  OC1~, organic chloramines, and other interferences.

    A water pollution investigation  (139) of the Fields Brook, Ashtabula River
and Harbor  (Ashtabula, Ohio) revealed high concentrations of chlorine, using the
orthotolidine method, resulting from industrial discharges.  Measurements of
total residual chlorine in Fields Brook varied from approximately 1 to 12 mg/1
near its mouth.  One measurement of 35 mg/1 was recorded at an outfall.
Concentrations were reduced by dilution in the Ashtabula River to 0.03 to 0.05 mg/1.
                                          26

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Aquatic populations were greatly reduced but may have been the result of high
concentrations of other toxic materials.

    Chlorination of urban water supplies has been found responsible for two
epidemics of acute hemolytic anemia in uremic patients undergoing hemodialysis
(lUO).  Chloramines produced denaturation of hemoglobin by their direct oxidizing
capacity and their ability to inhibit red cell reductive metabolism.  In
relation to this problem of methemoglobin production in human blood by
chloramine, Grothe and Eaton (lUl) exposed two groups of fathead minnows to a
potentially lethal concentration of monochloramine (1.5 mg/l) and compared the
methemoglobin concentrations in their blood with those in control fish.  After
a 1-hr exposure the concentrations of methemoglobin in the blood of
monochloramine-exposed fish were 32.0 and 29.^ percent of total hemoglobin,
and in the control fish the concentrations were 2.8 and 2.6 percent of total
hemoglobin.  The authors concluded that lethal concentrations of chloramine
apparently kill fish by virtue of their powerful ability to oxidize hemoglobin
and cause death by anoxia when the red cells can no longer deliver an adequate
oxygen supply to the tissues.

    Studies (U5) described earlier with aquatic invertebrates used a chlorine-
dosing system designed to control intermittent and periodic additions of chlorine.
This dosing system has been described in detail by Gregg and Heath (lU2).
It is basically a. timer-operated pump set to" simulate the chlorination schedule
of many steam-electric generating plants.
    Cairns et_ al_.  (l^3, 1^4) suggested that, since chlorine causes the epithelium
of fish gills to slough off, and a copious amount of mucus is produced which clogs
the gill lamellae, asphyxia may be a major cause of death resulting from exposure
to TRC.  Consequently, they hypothesized that elevated temperatures, which would
lower dissolved oxygen and increase the respiratory demand for oxygen, probably
would increase the toxic ity of chlorine to fish.

    Katz (lU5) studied the influence of sodium, potassium, calcium, and magnesium
on the acute toxicity of chlorine to mosquitofish under static bioassay
conditions using tap water dechlorinated by direct sunlight, deionized water,
and several concentrations of sea water.  Free and combined residual chlorine
were measured during the exposures by the orthotolidine and sodium arsenite
methods.  Sodium at concentrations between 500 and 3,000 mg/1 most effectively
reduced the toxicity of 0.5 and 1.0 mg/1 chlorine and prolonged survival time
of the test fish.  Lower sodium concentrations did not influence toxicity, and
mortality at higher concentrations of sodium probably reflected osmotic stress.
When the mosquitofish were acclimated to 25 percent sea water before transfer to
tap water with chlorine added, they were significantly more resistant to the chlorine
than fish acclimated to tap water.  When 100 mg/1 of calcium was added to tap water or
when equivalent amounts of both calcium and sodium were added to distilled water,
chlorine toxicity was similar to an exposure to chlorine in tap water, which indicates
that calcium nullified the protective action of the sodium ion.  This ionic
interplay with chlorine was highly suggestive of some membranal effect.  Katz
also described several studies that evaluated the influence of chlorine on gill
membrane permeability.  Sodium efflux and gain in fish weight were a direct
consequence of the addition of chlorine.  The author suggested that ammonia
excreted by fish gills rapidly converts free chlorine to chloramines so that
the fish would be exposed mainly to combined chlorine.  A model was presented,
                                          27

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based on the results of these studies, for the action of chlorine  in the
gill of freshwater fish.  Consequences of physiological effects at the
membrane and environmental levels were discussed.

     Yearling coho salmon were exposed for 12 weeks to chlorinated sewage plant
effluent diluted with seawater under continuous flow conditions   (lW>).
Concentrations of effluent of 1.1 and 3.6 percent  (0.009 and 0.03  mg/liter of TRC,
respectively, resulted in reductions of hemoglobin and hematocrit  to levels
indicative of anemia.  Observations of the erythrocytes revealed  lysed  and
degenerating cells, increased numbers of circulating immature  cells, and
abnormal cells.  The highest tested no-effect concentration of TRC was
0.003 mg/liter (0.3 percent effluent).


AQUATIC LIFE CRITERIA AND APPLICATION FACTORS

     Various problems arise during the development of aquatic  life criteria.  One
principal difficulty is evaluating the quality of  the available data so that
their influence on the eventual recommendations is proportional to their  importance
and accuracy.  As discussed earlier, the analytical method used in various studies
can have a great influence on the accuracy of the  result  , whether chemical or
biological.  However, unless the investigator specifically compares two or more
methods, one of which is amperometric, there is no way to measure  the accuracy of
his results.  No quality control procedure can be  applied to data generated
years ago.  Consequently anyone attempting to summarize and evaluate research
data before developing a recommendation or criterion should accept the  results
of most analytical methods for TRC but the possible limitations of the  data
should not be forgotten.

     Criteria for freshwater aquatic life have been recommended  (9) for both
continuous and intermittent exposures of TRC.  Criteria were recommended
for both coldwater fish species and warmwater fish species, a  distinction that
is becoming less justifiable because of the  sensitivity of various minnows
(l8, 25, 52, 75).  For continuous and intermittent exposures to TRC the
criteria for trout and salmon and most aquatic organisms were  0.002 and Q.Ob
mg/1, respectively.  For warmwater fish species and less  sensitive aquatic
species the criteria were 0.01  (continuous)  and 0.2 mg/1  (intermittent).  The
criteria for intermittent exposures to TRC were applicable for up to 2  hr/day.
Basch and Truchan (l^7) developed comparable TRC criteria for  freshwater  fish.
Their criteria for coldwater fish species were 0.005 mg/1 for  continuous  exposure
and 0.0k mg/1 for intermittent  exposure.  For warmwater  species the criteria
were 0.02 and 0.2 mg/1 for continuous and intermittent exposure,  respectively.
The National Academy of Sciences  (lU8) in its compilation of freshwater aquatic
life criteria recommended a single maximum TRC concentration of 0.003 mg/1 at  any
time or place.  They also concluded that aquatic organisms can tolerate short-term
exposure to higher concentrations.  Consequently,  it was  also  recommended that
when intermittent chlorination  is used TRC should  not exceed 0.05 mg/1  for
no longer than 30 min in any 2^-hr period.   For marine aquatic life the National
Academy of Sciences  (lU8) recommended an application factor of 0.1 and  96-hr LC50
data from sea-water bioassays for the most sensitive species to be protected.
They also suggested that free residual chlorine in sea water in  excess  of 0.01
mg/1 can be hazardous to marine life.
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    As discussed earlier, Mattice and Zittel  (.581 plotted available data
on median effect concentrations of TRC on freshwater and marine organisms and
estimated acute and chronic toxicity thresholds for each group.  These thresholds
represent a dose-time combination below which there are either no deaths  (acute
threshold) or no effect, no matter how long the exposure (chronic threshold).  The
freshwater and marine acute thresholds are different, but both are time dependent.
The chronic toxicity thresholds are constant and for freshwater and marine
organisms are 0.0015 and 0.02 mg/1, respectively.  As a result of apparent basic
differences in sensitivity of freshwater and marine organisms, which
may be the result of different TRC chemistry, the time at which the chronic
thresholds begin are different.  For freshwater organisms the chronic threshold
begins at nearly 1,000 min of exposure, whereas for marine organisms it begins at
just over 100 min.  The authors indicated that these thresholds were for protection
of aquatic life; the implication of a no-effect chronic threshold for continuous
exposure to chlorine seems consistent with the purpose of developing aquatic life
criteria.  The freshwater threshold (0.0015 mg/l) is similar to the criteria for
all freshwater aquatic life discussed earlier (0.002 mg/1 (9), 0.003 mg/1
and 0.005 mg/1
    The European Inland Fisheries Advisory Commission  (1^9) recommended criteria
for European freshwater fish species.  They attempted  to  convert most published
data on TRC toxicity to free chlorine, and the recommended criterion was  O.OQlt
mg/1 of free chlorine.  Total residual chlorine criteria  were temperature and
pH dependent, but not ammonia dependent, and ranged from  0.00^ to  0.121 mg/1.
They concluded that chlorine is too reactive to be very persistent in most streams,
and the upper limit for fish survival could be set closer to lethal levels since
avoidance is likely to provide additional protection at higher concentrations.
They tentatively suggested that the criterion be 0.004 mg/1 of free chlorine,
which should result in few or no fish deaths.

    A concept commonly used for the development of criteria for freshwater
fish is the application factor.  An application factor is the ratio between
an experimentally derived safe concentration of a toxicant and the 96-hr  LC50.
Application factor criteria for freshwater aquatic life have been  recommended  (l^8)
for such materials as copper, nickel, zinc, un-ionized ammonia, free cyanide,
linear alkylate sulfonates, and phenolics.

    Safe and 96-hr LC50 concentrations of residual chlorine for freshwater fish were
reported in three different studies.  Arthur and Eaton (.150) in studying  the effect
of chloramines on the fathead minnow observed a safe concentration for all life stages,
including reproduction, of 0.0165 mg/1.  The 96-hr LC50 calculated with their  data
was 0.120 mg/1.  The application factor would then be  O.lU.  Arthur et_ aO^. (28)
used chlorinated secondary wastewater effluent and also determined safe and 96-hr
LC50 concentrations of TRC for the fathead minnow; the concentrations were 0.01 4
and 0.108 mg/1 (means 0.130 and 0.086 mg/l), respectively.  The application factor
would be 0.13.  Ward et_ al^. (29) also used chlorinated secondary effluent and  the
fathead minnow.  Their safe and 96-hr LC50 concentrations were 0.010 and  0.089 mg/l,
respectively.  The individual LC50 values were 0.095 and  0.082 mg/l.  Again,
with their data the application factor would be 0.11.  The mean of these  three
application factors is 0.13, or approximately one-eighth.

    Of the three chronic studies with fathead minnows  (.28, 29, 150) two (28, 29)
concluded that growth or survival was as sensitive as  or  more sensitive than
reproduction in estimating the chronic safe concentration.  If we assume, therefore,
                                           29

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that growth is a sensitive indicator of chronic TEC effects on fish, the data
of Warren (38) may be used to calculate an application factor also.  He has
conducted several growth studies with coho salmon exposed to chloramines.  Growth
was inhibited at TRC concentrations between 0.020 and 0.02^ mg/1; no effects on
growth were detected at 0.010 to 0.012 mg/1.  The mean of his 96-hr LC50 values
was 0.077 mg/1.  When we use 0.011 mg/1 as an estimate of the safe concentration for
coho salmon, the application factor, based on coho salmon data, is 0.1^.  The mean
application factor derived from the three fathead minnow chronic tests is 0.13.

    The purpose of the application factor (151) is to estimate safe concentrations
for fish species that cannot, or probably would not, be tested chronically in
the laboratory.  A ninety-six-hr LC50 value for a specific toxicant is determined
for such a species, and this value is multiplied by the application factor for that
toxicant in order to estimate safe concentrations for chronic exposure of the
species to the toxicant in question.  If we use the 96-hr LC50 values for TRC for
the most sensitive freshwater fish species such as trout, salmon, and minnows and
multiply these values by one-eighth, we are estimating their approximate safe
concentrations for chronic exposure to TRC.  Most of the 96-hr LC50 values
for these more sensitive fish species range between O.OUO and 0.080 mg/1.  The
estimated safe concentrations of TRC would therefore range between 0.005 and
0.010 mg/1.  The minimum estimate of 0.005 mg/1 is consistent with those criteria
discussed earlier that range from 0.002 to 0.005 mg/1.  It is obvious that an
application factor of one-eighth (0.13) will provide no "margin of safety" in that
it results in a criterion that is very close to a lethal concentration.  Mattice
and Zittel (58) concluded that a barely non-lethal concentration of TRC can be
estimated by multiplying the 96-hr LC50 by 0.37> or about one-third.  Since
one-third of a 96-hr LC50 is an estimate of an acute, non-lethal concentration of
TRC and one-eighth  of a 96-hr LC50 is an estimate of a chronic, safe concentration
of TRC, the narrowness of the lethal-to-safe range is of significant concern.

    The U.S. Environmental Protection Agency, in its compilation of water
quality criteria  (152), has proposed aquatic life criteria for chlorine.  For
salmonid fish the criterion was 0.002 mg/1, and for marine and other freshwater
organisms the criterion was 0.010 mg/1.  These criteria, if approved, will be sent
to the States, who will consider them in the process of developing proposed
State standards for receiving waters.  The data summarized in this review would
support a single  criterion for TRC of 0.003 mg/1 for freshwater aquatic life
continuously exposed to TRC.  The more recent data on warmwater fish species
necessitates this change from the two-criteria concept.

    Criteria for  intermittent exposure of aquatic organisms to TRC should be
time related and  those developed by Mattice and Zittell  (58) are appropriate
at this time.
REGULATIONS

    The U.S. Environmental Protection Agency recently proposed (153)  an  amendment
of the Secondary Treatment Information regulation  contained in kO  CFR Part  133
and promulgated pursuant to  Section  304(d)(l)  of the  Federal Water Pollution
Control Act Amendments  of 1972.   Section  30l(b)(l)(B)  of this act  required
that  effluent  limitations, based  on  secondary treatment,  be achieved  on  all publicly
owned treatment works in existence on July 1,  1977» or approved for a
construction grant  prior to  June  30, 197^.   The proposed amendment deleted
the fecal  coliform  bacteria  limitations from the definition of secondary


                                         30

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treatment.  An agency task force (15^1 reviewed the U.S. Environmental Protection
Agency policy on wastewater disinfection and the use of chlorine.  It became
evident that present disinfection policy inadvertently encouraged the use of
chlorine to control "bacteria since nearly all facilities were using chlorine
or chlorine-based compounds.  In some instances the present policy required
disinfection even when it was unnecessary.  Now the U.S. Environmental
Protection Agency intends that disinfection only be considered when public
health hazards need to be controlled.  The exclusive use of chlorine for
disinfection should not be continued where protection of aquatic life is of
primary consideration.  Alternate means of disinfection and disinfectant control
(dechlorination) must be considered where public health hazards and potential
adverse impact on the aquatic and human environments co-exist.  Disinfection
should not be required where no benefits accrue.
                                       31

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                                   SECTION VI

                                   REFERENCES
 1,   Cole,  S.  A.,  and Baker, R.  J.,  "Pollution Aspects of Residual
          Chlorine in Cooling and Waste-water Discharges."  Proc.
          3_Uth Intl.  Water Conf. Eng.  Soc. Western Penn.   Pennwalt Corp.,
          Wallace  & Tiernan Div., Belleville, N.J., Report T31WC  (October
          1973).

 2.   Baker, R. J., and Cole, S.  A.,  "Residual Chlorine: Something New
          to Worry About."  Ind. Water Eng., 11, 10 (197^).

 3.   Collins,  H. F.,  and Deaner, D.  G., "Sewage Chlorination Versus
          Toxicity—A Dilemma?"  Jour. Environ. Eng. Div., 99, ?6l
          (1973).                                           ~

 h.   Snoeyink, V.  L., and Markus, F. I., "Chlorine Residuals in Treated
          Effluents." Water & Sew. Works, 121, 35 (1971*).

 5.   McKersie, J., "A Study of Residual Chlorine Below Selected Sewage
          Treatment Plants in Wisconsin, Summer, 197^."  Wisconsin
          Department of Natural Resources, Div. of Environmental Standards,
          Bur. of  Water Quality, Madison, Wis. (October 197*0.

 6.   White, G. C., Handbook of Chlorination.  Van Nostrand Reinhold Co.,
          New York, N.Y. (1972).

 7.   Harr, T.  E.,  "Residual Chlorine in Wastewater Effluents Resulting from
          Disinfection."  New York  State Department of Environmental
          Conservation, Tech. Paper No. 38, Albany, N.Y.  (March 1975).

 8.   The Commissioners, "The Best Means of Preventing the Pollution of Rivers.
          Vol. I.   Report and Plans."  Rivers Pollution Commission (1868),
          George Edward Fryre and William Spottiswoode, London, England  (l870),

 9.   Brungs, W. A., "Effects of Residual Chlorine on Aquatic Life."
          Jour. Water Poll. Control Fed., j*5, 2180  (1973).

10.   Tsai, Chu-fa, "Effects of Sewage Treatment Plant Effluents on Fish:
          A Review of Literature."   Chesapeake Research Consortium, Inc.,
          CRC Pub. No. 36; Center for Environmental and Estuarine Studies,
          University of Maryland, Contribution No. 637» College Park, Md.
           (1975).
                                       32

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11.   Podoliak, H. A., "A Review of the Literature on the Use of Calcium
          Hypochlorite in Fisheries."  U.S. Fish and Wildlife Service,
          Bureau of Sport Fisheries and Wildlife, Ho. PB-235-^1*,
          NTIS, U.S. Department of Commerce, Washington, D.C. (197M.

12.  Becker, C. D., and Thatcher, T. 0., "Toxicity of Power Plant Chemicals
          to Aquatic Life."  Battelle-Pacific Northwest Laboratories,
          Kept. No. WASH-12U9, UC-11 Richland, Wash. (June 1973).

13.  Whitehouse, J. W., "Chlorination of Cooling Water:  A Review of
          Literature on the Effects of Chlorine on Aquatic Organisms."
          Central Electricity Research Laboratories, Laboratory
          Memorandum No. RD/L/M 1*96 (Job No. VJ kkO), Leatherhead, Surrey,
          England (1975).

lU.  Mattice, J. S., and Pfuderer, H. A., "Chemistry and Effects of
          Chlorine in Aquatic Systems: A Selected Annotated Bibliography."
          Oak Ridge National Laboratory, Oak Ridge, Tenn.  ORNL/EIS-82
          (Environmental Sciences Division Pub. No.  808) (March 1976).

15.  Evins, C., "The Toxicity of Chlorine to Some Freshwater Organisms."
          Resources Division, Water Research Centre, Stevenage Laboratory,
          Tech. Rept. TR8, Elder Way, Stevenage, Herts. SGI 1TH (March 1975),

l6.  Davis, W. P., and Middaugh, D. P., "Impact of Chlorination Processes
          on Marine Ecosystems."  Presented at the Conference on the
          Environmental Impact of Water Chlorination, October 22-2*+, 1975,
          at Oak Ridge National Laboratory, Oak Ridge, Tenn.
          Proceedings to be published.

17.  Brooks, A. S., and Seegert, G. L., "The Toxicity of Chlorine to
          Freshwater Organisms Under Varying Environmental Conditions."
          Presented at the Conference on the Environmental Impact of
          Water Chlorination, October 22-2^, 1975, at Oak Ridge National
          Laboratory, Oak Ridge, Tenn.  Proceedings to be published.

18.  United States of America Nuclear Regulatory Commission, "Applicant's
          Critical Review and Study as Requested by the Atomic Safety
          and Licensing Board, Relative to WNP-1 and h and the Columbia
          River."  Court Docket Nos. 50-U60 and 50-513, Washington, D.C.
          (1975).

19.  Servizi, J. A., and Martens, D. W., "Preliminary Survey of Toxicity
          of Chlorinated Sewage to Sockeye and Pink Salmon."  International
          Pacific Salmon Fisheries Commission, Progress Kept. Wo. 30,
          New Westminister, B.C., Canada (197U).

20.  Tsai, Chu-fa, "Water Quality and Fish Life Below Sewage Outfalls."
          Trans. Amer. Fish. Soc., 102, 28l (1973).

21.  Olson, C. L., "Effect of Chlorinated Sewage Effluent on the Iowa
          River, Marshalltown, Iowa."  Master of Science Thesis, Iowa
          State University, Ames, Iowa (1975).
                                      33

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22.  Norris, D. P., et_ al_., "Marine Waste Disposal—A Comprehensive
          Environmental Approach to Planning."  Jour. Water Poll. Control
          Fed., J&, 52 (1973).

23.  Bellanca, M. A., and Bailey, D. S., "A Case History of Some Effects of
          Chlorinated Effluents on the Aquatic Ecosystem in the Lover James
          River in Virginia."  Presented at the *i8th Annual Conference of the
          Water Pollution Control Federation, October 5-10, Miami Beach,
          Fla.  (1975).

2k.  Muchmore, D., and Epel, D., "The Effects of Chlorination of Wastewater
          on Fertilization in Some Marine Invertebrates."  Marine Biol.
          (W. Ger.), J£, 93 (1973).

25.  Martens, D. W., and Servizi, J. A., "Acute Toxicity of Municipal
          Sewage to Fingerling Sockeye Salmon."  International Pacific
          Salmon Fisheries Commission, Progress Kept. No. 29,
          New Westminister, B.C., Canada (197*0.

26.  Esvelt, L. A., et_ al_., "Toxicity Assessment of Treated Municipal
          Wastewaters."  Jour. Water Poll. Control Fed., jj-5, 1558 (1973).

27.  Stone, R. W., et_ aJ^., "Long-Term Effects of Toxicants and Biostimulants
          on the Waters of Central San Francisco Bay."  Sanitary Engineering
          Research Laboratory, University of California, SERL Rept. No. 73-1,
          Berkeley, Calif. (May 1973).

28.  Arthur, J. W., et_ al_., "Comparative Toxicity of Sewage-Effluent
          Disinfection to Freshwater Aquatic Life."  U.S. Environmental
          Protection Agency, Duluth, Minn.  Ecological Research Series
          EPA-600/3-75-012 (1975).

29.  Ward, R. W., et_ al_., "Disinfection Efficiency and Residual Toxicity of
          Several Wastewater Disinfectants.  Volume I - Grandville, Michigan."
          U.S.  Environmental Protection Agency, Cincinnati, Ohio.  Ecological
          Research Series (in press),

30.  Ward, R. W., "The Effects of Chlorination and Alternative Methods of
          Wastewater Disinfection on the Fathead Minnow  (Pimephales promelas)."
          Presented at the U8th Annual Conference of the Water Pollution
          Control Federation, October 5-10, Miami Beach, Fla.  (1975).

31.  Shumway, D. L., and Palensky, J. R., "Impairment of the Flavor of Fish
          by Water Pollutants."  Environmental Protection Agency, Washington,
          D.C.   Ecological Research Series EPA-R3-73-010  (1973).

32.  Eren, Y.,  and Langer, Y., "The Effect of Chlorination on Tilapia Fish."
          Bamidgeh, 25, 56 (1973).

33.  Carpenter,  E. J., et^ al^., "Cooling Water Chlorination and Productivity
          of Entrained Phytoplankton."  Marine Biol.  (W. Ger.), JL6, 37  (1972).

3^.  Gentile, J. H., et_ al_.,  "Power Plants, Chlorine, and Estuaries."
          Presented at the lOUth Annual Meeting of the American Fisheries
          Society, September  9-11, Honolulu, Hawaii  (197*0.


                                       31*

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35.   Wolf, E. G., et_£Q., "Toxicity Tests on the Combined Effects of
           Chlorine and Temperature on Rainbow (Salmo gairdneri) and Brook
           (Salvelinus fontinalis) Trout."  Proc. 2nd Thermal Ecology
           Symposium, April 2-5, Augusta, Ga. (1975).

36.   Thatcher, T. 0., et_ al., "Bioassays on the Combined Effects of Chlorine,
           Heavy Metals and Temperature on Fishes and Fish Food Organisms
           Part I.  Effects of Chlorine and Temperature on Juvenile Brook
           Trout (Salvelinus fontinalis)."  Bull. Environ. Contain. Toxicol.,
           15, UO (1976).

37.   Schneider, M. J., et_ al., "Aquatic Physiology of Thermal and Chemical
           Discharges."  In "Environmental Effects of Cooling Systems at
           Nuclear Power Plants."  International Atomic Energy Agency,
           Vienna.  Battelle-Pacific Northwest Laboratories, Kept. No.
           IAEA-SM-187/15, Richland, Wash. (1975).

38.   Warren, C. E., "Laboratory Determination of Chloramine Concentrations
           Safe for Aquatic Life."  Oregon State University, Department of
           Fisheries and Wildlife, Quarterly Progress Repts., EPA Grant
           No. R-802286, Corvallis, Oreg. (197^-1976).

39.   Tsai, Chu-fa, and Tompkins, J. A., "Survival Time and Lethal Exposure
           Time for the Blacknose Dace Exposed to Free Chlorine and
           Chloramine Solutions."  Water Resources Research Center, University
           of Maryland, Technical Report No. 30, College Park, Md. (197*0.

hO.   Roseboom, D. P., and Richey, D. L., "The Acute Toxicity of Chlorine on
           Bluegill and Channel Catfish in Illinois."  Illinois State Water
           Survey, Water Quality Section, Peoria, 111. (1975).

kl.   Carlson, A. R., "Reproductive Behavior of the Threespine Stickleback
           Exposed to Chloramines."  Master of Science Thesis, Oregon State
           University, Corvallis, Oreg. (1976).

k2.   Alderson, R., "Effects of Low Concentrations of Free Chlorine on Eggs
           and Larvae of Plaice, Pleuronectes platessa L."  Food and
           Agriculture Organization of the United Nations Technical Conf.
           on Marine Pollution and Its Effects on Living Resources and Fishing,
           December 9-l8, Rome, Italy.  Rept. No. FIR: MP/TO/E-3
           (1970).

1*3.   Hughes, J. S., "Acute Toxicity of Thirty Chemicals to Striped Bass
           (Morone saxatilis)."  Presentation at the Western Association
           of State Game and Fish Commissioners, Salt Lake City, Utah
           (July 1973).

UU.   Middaugh, D. P., et_ al^., "Toxicity of Chlorine to Juvenile Spot,
           Leiostomus xanthurus."  U.S. Environmental Protection Agency,
           Bears Bluff Field Station, John's Island, S.C. (1976).

1*5.   Gregg, B. C., "The Effects of Chlorine and Heat on Selected Stream
           Invertebrates."  Ph.D. Thesis, Virginia Polytechnic Institute
           and State University, Blacksburg, Va. (December 197M.
                                      35

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1*6.  Grossnickle, N. E., "The Acute Toxicity of Residual Chlorainine to
          the Rotifer Keratella cochlearis (Gosse) and the Effect of
          Dechlorination with Sodium Sulfite."  Master of Science Thesis,
          University of Wisconsin, Milwaukee, Wise. (August 197M.

1+7.  Roberts, M. H., Jr., et_ al_., "Acute Toxicity of Chlorine to
          Selected Estuarine Species."  Jour. Fish. Res. Bd. Can.
          ^ 2525 (1975).

1*8.  Bender, M. E., et_ al_., "Effects of Residual Chlorine on Estuarine
          Organisms 1 & 2."  In "Technology and Ecological Effects of
          Biofouling Control Procedures at Thermal Power Plant Cooling
          Water Systems (Loren D. Jensen, editor)."  Proceedings of a
          Workshop held at The Johns Hopkins University, June 16-17, 1975.
          Ecological Analysts, Inc., Wantagh, N.Y. (February 1976).

1*9.  Roberts, M. H., Jr., and Diaz, R. J., "Toxicity of Chlorine to Marine
          Phytoplankton."  Jour. Fish. Res. Bd. Can, (in press).

50.  Gibson, C. I., et_ al_., "Some Effects of Temperature, Chlorine and
          Copper on the Survival and Growth of the Coon Stripe Shrimp,
          Pandalus danae."  Proc. 2nd Thermal Ecology Symposium,
          April 2-5, Augusta, Ga. (1975).

51.  Beeton, A. M., et_ al., "Effects of Chlorine and Sulfite Reduction
          on Lake Michigan Invertebrates."  U.S. Environmental Protection
          Agency, Duluth, Minn.  Ecological Research Series EPA-600/3-76-036.
          132 p.  (1976).

52.  Sanders, J. E., et_ al_., "Control of  the Infectious Protozoan
          Ceratomyxa shasta by Treating Hatchery Water Supplies."  Progressive
          Fish Culturist, 3h. 13  (1972).

53.  Toetz, D., et_ al_., "Effects of Chlorine and Chloramine on Uptake of
          Inorganic Nitrogen by Phytoplankton."  Water Res.  (G.B.) (in press).

5!*.  White, G. C., "Current Chlorination  and Dechlorination Practices in the
          Treatment of Potable Water, Wastewater and Cooling Water."  Presented
          at the Conference on the Environmental Impact of Water Chlorination,
          October  22-21*,  1975, at Oak Ridge National Laboratory, Oak Ridge,
          Tenn. Proceedings to be published.

55.  Cole, S. A.,  "Chlorination fof the Control of Biofouling in Thermal
          Power Plant  Cooling Water Systems."  In  "Technology and Ecological
          Effects  of Biofouling Control Procedures at Thermal Power Plant
          Cooling  Water Systems  (Loren D. Jensen,  editor)."  Proceedings of
          a Workshop held at The Johns Hopkins University, June  16-17,  1975.
          Ecological Analysts,  Inc., Wantagh, N.Y.  (February 1976).

56.  Draley, J. E., "Biofouling Control in Cooling Towers and Closed Cycle
          Systems."  In  "Technology and Ecological Effects of Biofouling
          Control  Procedures at Thermal Power Plant Cooling Water Systems
           (Loren D. Jensen, editor)."  Proceedings of a Workshop  held at
          The  Johns Hopkins University, June l6-17, 1975.  Ecological
          Analysts, Inc., Wantagh, N.Y.  (February  1976).


                                      36

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57.  Baker, R. J., "The Measurement of Chlorine Compounds."  In "Technology and
          Ecological Effects of Biofouling Control Procedures at Thermal Power
          Plant Cooling Water Systems (Loren D. Jensen, editor}."  Proceedings
          of a Workshop held at The Johns Hopkins University, June 16-1T, 1975.
          Ecological Analysts, Inc., Wantagh, N.I. (February 1976).

58.  Mattice, J. S., and Zittel, H. E. , "Site Specific Evaluation of Power
          Plant Chlorination:  A Proposal."  Jour. Water Poll. Control Fed.
          (in press).

59.  Mattice, J. S., "A Method for Estimating the Toxicity of Chlorinated
          Discharges."  In "Report of a Workshop on the Impact of Thermal
          Power Plant Cooling Systems on Aquatic Environments."  Electric
          Power Research Institute, Palo Alto, Calif.  EPRI SR-38, Volume II,
          pp. lte-155 (April 1976).

60.  Brungs, W. A., "General Considerations Concerning the Toxicity to
          Aquatic Life of Chlorinated Condenser Effluent."  In "Technology
          and Ecological Effects of Biofouling Control Procedures at Thermal
          Power Plant Cooling Water Systems (Loren D. Jensen, editor)."
          Proceedings of a Workshop held at The Johns Hopkins University,
          June 16-17, 1975-  Ecological Analysts, Inc., Wantagh, N.Y.
          (February 1976).

6l.  Dickson, K. L. , et_ al . , "Effects of Intermittently Chlorinated
          Cooling Tower Blowdown on Fish and Invertebrates."  Environ .
          Sci. Technol. >8A 81*5 (197*0.
62.  Basch, R. E., and Truchan, J. G. , "Toxicity of Chlorinated Power
          Plant Condenser Cooling Waters to Fish."  U.S. Environmental
          Protection Agency, Duluth, Minn.  Ecological Research Series
          EPA-600 /3-76-009.  115 P- (1976).

63.  Truchan, J. G., "Toxicity of Residual Chlorine to Freshwater Fish:
          Michigan's Experience."  In "Technology and Ecological Effects
          of Biofouling Control Procedures at Thermal Power Plant Cooling
          Water Systems (Loren D. Jensen, editor)."  Proceedings of a
          Workshop held at The Johns Hopkins University, June 16-17, 1975.
          Ecological Analysts, Inc., Wantagh, N.Y. (February 1976).

6k.  Marcy, B. C., Jr., "Vulnerability and Survival of Young Connecticut
          River Fish Entrained at a Nuclear Power Plant."  Jour. Fish.
          Res. Bd. Can. , J50, 1195 (1973).

65.  Eiler, H. 0., and Delfino, J. J., "Limnological and Biological
          Studies of the Effects of Two Modes of Open-Cycle Nuclear
          Power Station Discharge on the Mississippi River (1969-1973)."
          Water Res. (G.B.),Ji, 995 (.197*0.

66.  Fox, J. L., and Moyer, M. S., "Effect of Power Plant Chlorination
          on Estuarine Productivity."  Chesapeake Sci., 16, 66 (1975).
                                      37

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67.  Polgar, T. T., et_ al_., "Assessment of Near Field Manifestations of
          Power Plant Induced Effects on Zooplankton."  Proc. 2nd
          Thermal Ecology Symposium, April 2-5, Augusta, Ga. (1975).

68.  Seegert, G. L., et_ al., "The Effects of a 30-Minute Exposure of
          Selected Lake Michigan Fishes and Invertebrates to Residual
          Chlorine."  In "Technology and Ecological Effects of Biofouling
          Control Procedures at Thermal Power Plant Cooling Water Systems
          (Loren D. Jensen, editor)."  Proceedings of a Workshop held at The
          Johns Hopkins University, June 16-17, 1975-  Ecological Analysts,
          Inc., Wantagh, N.Y. (February 1976).

69.  Brooks, A. S., "Investigations of the Effects of Chlorinating Power
          Plant Cooling Water on the Biota of Lake Michigan."  Center for
          Great Lakes Studies, The University of Wisconsin, Semi-Annual
          Research Progress Report, Milwaukee, Wis.  25 p.  (June 1975 -
          December 1975).

70.  Brooks, A. S., and Seegert, G. L., "Investigations of  the Effects of
          Chlorinating Power Plant Cooling Water on the Biota of Lake
          Michigan: Repeated 5-Minute Exposures of Rainbow  Trout and Yellow
          Perch to Chlorine at 10 and 20 C."  Center for Great Lakes Studies,
          The University of Wisconsin, Milwaukee, Wis.  (March 1976).

71.  Bass, M. L., and Heath, A. G., "Physiological Effects  of Intermittent
          Chlorination on Fish."  Amer. Zoologist, ^15.^  8l8  (1975).

72.  Bass, M. L., and Heath, A. G., "Cardiovascular and Respiratory Changes
          in Rainbow Trout, Salmo gairdneri, Exposed Intermittently to
          Chlorine."  Water Res.  (G.B.) (in press).

73.  Bass, M. L., efc_ al., "Histopathological Effects of Intermittent Chlorine
          Exposure on Bluegill (Lepomis macrochirus) and Rainbow Trout
          (Salmo gairdneri)."  Virginia Polytechnic Institute and State
          University, Blacksburg, Va. (1975).

7U.  Bass, M. L., "A Study of Lethality and Toxic Mechanisms of Intermittent
          Chlorination to Freshwater Fish."  Ph.D. Thesis,  Virginia Polytechnic
          Institute and  State University, Blacksburg, Va. 70 p.  (1975).

75.  Bass, M. L., and Heath, A. G., "Toxicity of Intermittent Chlorine
          Exposure to Bluegill Sunfish, Lepomis macrochirus:  Interaction
          with Temperature."  Assoc. Southeast Biol. Bull.,.22A 1*0  (1975).

76.  Heath, A. G., "A Preliminary  Investigation of Chlorine Toxicity to
          Fish and Macroinvertebrates: Interactions with Temperature."
          Final Report on Grant with American Electric  Power Service
          Corporation.   Virginia Polytechnic Institute  and  State University,
          Blacksburg, Va.  (December 197*0.

77.  Dickson, K.  L., and Cairns, J., Jr., "Effects of Intermittent Chlorination
          on Aquatic Organisms and Communities."  Presented at the *t8th Annual
          Conference of  the Water  Pollution Control Federation, October  5-10,
          Miami Beach, Fla.  (1975).
                                       38

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78.  Collins, H. L. , Personal Communication.  Department of Biology,
          University of Minnesota, Duluth, Minn. (1976).

79.  Stober, Q. J., and Hanson, C. H. , "Toxicity of Chlorine and Heat to
          Pink (Oncorhynchus gorbuscha) and Chinook Salmon ((). tshawytscha) . "
          Trans. Amer. Fish. Soc..  ,0,^- 659
80.  Hoss, D. E., e^ al . , "Effects of Temperature , Copper and Chlorine
          on Fish During Simulated Entrainment in Power-Simulated
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          and Biological Effects on the Environment of Cooling Systems
          and Thermal Discharges at Nuclear Power Stations, August 26-30,
          Oslo, Norway (197^).

8l.  Margrey, S. L. , et aiU , "A Preliminary Study of Chlorine Toxicity to
          Atlantic Menhaden (Brevoortia tyrannus ) and Hogchoker (Trinectes
          maculatus ) . "  Academy of Natural Sciences of Philadelphia,
          Benedict Estuarine Research Laboratory, Solomons, Md.  Abstract
          (only) published in the Assn. Southeastern Biol. Bull. (April
          1976).

82.  Alderson, R., "Sea-Water Chlorination and the Survival and Growth of the
          Early Developmental Stages of Plaice, Pleuronectes platessa L. ,
          and Dover Sole, Solea solea (L.)."  Aquaculture , k^ hi (1971*).

83.  Nash, C. E., "Residual Chlorine Retention and Power Plant Fish Farms."
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Qh.  McLean, R. I., "Chlorine Tolerance of the Colonial Hydroid Bimeria
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          _____^_ ______^         ^     — —   -
85.  McLean, R. I., "Chlorine and Temperature Stress on Estuarine
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86.  Dressel, D. M. , "The Effects of Thermal Shock and Chlorine on the
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87.  Latimer, D. L. , "The Toxicity of 30-Minute Exposures of Residual
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88.  Latimer, D. L. , et^ al . , "Toxicity of 30-Minute Exposures of
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89.  Cairns, J., Jr., and Plafkin, J. L. , "Response of Protozoan Communities
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          (G.B. ),    937 (197*0.
                                      39

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 91.   Davies,  R.  M. ,  and Jensen,  L.  D. ,  "Zooplankton Entrainment at Three
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 97.   Armstrong, F. A.  J., and Scott, D. P., "Photochemical Dechlorination
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 98.  Shifrer, C. C., et_ al . , "Effects of Temperature on the Toxicity of
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           Laboratory, No. PRWG105-U, Logan, Utah (September 197*0.

 99.  Meldrim, J. W. , et_ al . , "The Effect of Temperature and Chemical
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100.  Bogardus, R. B. , et_ al_. , "The Avoidance Responses of Selected
           Wabash River Fishes to Mono-Chloramine . "  Jour. Water Poll.
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101.  Tsai, Chu-fa, and Fava, J. A., Jr., "Chlorinated Sewage Effluents and
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102.  Fava, J. A., Jr., and Tsai, Chu-fa., "Delayed Behavioral Responses
           of the Blacknose Dace (Rhinichthys atratulus ) to Chloramines and
           Free Chlorine."  Jour. Fish. Res. Bd. Can, (in press).

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103.   Fava, J. A., Jr., and Tsai, Chu-fa., "The Avoidance Reaction of
            Blacknose Dace, Rhinichthys atratulus (Hermann), to Domestic
            Sevage Effluents and Their Toxic Constituents."  Trans. Amer.
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10H.   Jolley, R. L., "Chlorination Effects on Organic Constituents in
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            Oak Ridge, Term. (1973).

105.   Jolley, R. L., "Determination of Chlorine-Containing Organics in
            Chlorinated Sewage Effluents by Coupled  6C1 Tracer—High-
            Resolution Chromatography."  Environ. Letters.7. 321  (197*0.
106.   Jolley, R. L. , "Chlorine-Containing Organic Constituents in Chlorinated
            Effluents."  Jour. Water Poll. Control Fed., Vf , 601  (1975).

107.   Jolley, R. L. , et_ al_. , "Analyzing Organics in Dilute Aqueous Solutions."
            Chemtech. 5? 312  (1975).

108.   Glaze, W. H., et_ al_. ,  "Analysis of Organic Materials in Wastewater
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            580  (1973).                                           />vs

109.   Glaze, W. H. , and Henderson, J. E., IV, "Formation of Organochlorine
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110.   Glaze, W. H., et_ al_. , "Analysis of New Chlorinated Organic Compounds
            Formed by Chlorination of Municipal Wastewater."  Presented at
            the Conference on the Environmental Impact of Water Chlorination,
            October 22-24, 1975, at Oak Ridge National Laboratory, Oak Ridge,
            Term.  Proceedings to be published.

111.   Jolley, R. L. , et_ a.l_. , "Chlorination of Cooling Water: A Source of
            Chlorine-Containing Organic Compounds with Possible Environmental
            Significance."  Proc. Fourth National Symposium on Radioecology,
            May 12-lU, Corvallis, Oreg. (1975).

112.   Jolley, R. L. , et_ al_. , "Determination of Chlorination Effects on Organic
            Constituents in Natural and Process Waters Using High-Pressure
            Liquid Chromatography."  Presented at the Symposium on the
            Identification and Analysis of Organic Pollutants in Water,
            First Chemical Congress of the North American Continent,
            November 30-December 5, Mexico City, Mexico  (1975).

113.   Rook, J. J., "Formation of Haloforms During Chlorination of Natural
            Waters."  Water Trt. & Exam. (G.B.),^, 231* (1971*).

Ilk.   Carlson, R. M. , et_ al_. , "Facile Incorporation of Chlorine into
            Armomatic Systems During Aqueous Chlorination Processes."
            Environ. Scj. Technol . ,,K 67^  (1975).

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115.   Carlson, R. M., and Caple. R., "Chlorine Utilization in Water Renovation
            Processes:  Chemical and Biological Implications."  U.S. Environmental
            Protection Agency, Ecological Research Series, Duluth, Minn.
            (Accepted for publication.)

Il6.   Carlson, R. M., and Caple, R., "Organo-Chemical Implications of Water
            Chlorination."  Presented at the Conference on the Environmental
            Impact of Water Chlorination, October 22-2k, 1975, at Oak Ridge
            National Laboratory, Oak Ridge, Tenn. Proceedings to be
            published.

117-   Kopperman, H. L., et_ al_., "Chlorinated Compounds Found in Waste Treatment
            Effluents and Their Capacity to Bioaccumulate."  Presented at the
            Conference on the Environmental Impact of Water Chlorination,
            October 22-21*, 1975, at Oak Ridge National Laboratory, Oak Ridge,
            Tenn.  Proceedings to be published.

118.   Barnhart, E. L., and Campbell, G. R., "The Effect of Chlorination
            on Selected Organic Chemicals."  U.S. Environmental Protection
            Agency, Washington, D.C.  Water Pollution Control Research Series
            12020 EXG 03/72 (March 1972).

119.   Leach, J. M., and Thakore, A. N., "Isolation and Identification of
            Constituents Toxic to Juvenile Rainbow Trout (Salmo gairdneri)
            in Caustic Extraction Effluents from Kraft Pulpmill Bleach
            Plants."  Jour. Fish. Res. Bd. Can., 32^ 121*9  (1975).

120.   Gehrs, C. W., et_ al.» "Effects of Stable Chlorine-Containing Organics
            on Aquatic Environments."  Nature, 2l*9, 675 (197*0.
121.   Eyman, L. D., et_ al., "Sublethal Effect  of  5-Chlorouracil  on  Carp
             (Cyprinus carpio) Larvae."  Jour. Fish. Res. Bd.  Can., 32,  2227
             (1975).                                                ~~

122.   Kopperman, H. L., _et_ al_. , "Aqueous Chlorination  and  Ozonation Studies.
             I.  Structure-Toxicity Correlations of Phenolic Compounds to
             Daphnia magna."  Chem.-Biol. Interactions,  9, 2** 5 (197*0.
123.   Katz, B. M., and Cohen, G. M., "Toxicities  of  'Excessively1  Chlorinated
            Organic Compounds."  Bull. Environ. Contain. Toxicol.  (in  press).

12l*.   Katz, B. M., and Cohen, G. M., "Relation Between Dissipation Kinetics
            and Toxicity."  Presented at  the  l*8th  Annual  Conference of the
            Water  Pollution Control  Federation, October 5-10, Miami Beach,
            Fla.  (1975).

125.   Morris, J.  C.,  "The Chemistry of Aqueous Chlorine  in Relation  to Water
            Chlorination."  Presented at  the  Conference on  the  Environmental
            Impact of  Water Chlorination,  October  22-21*,  1975,  at  Oak Ridge
            National Laboratory, Oak Ridge, Tenn.  Proceedings to be
            published.

126.   Morris, J.  C.,  and McKay, G., "Formation of Halogenated  Organics by
            Chlorination of Water Supplies."   U.S.  Environmental Protection
            Agency, Washington, D.C.  Environmental Health  Effects Research
            Series EPA-600/1-75-002  (March 1975).

                                       1*2

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127.   Dowty, B.,, et_ al., "Halogenated Hydrocarbons in New Orleans Drinking
            Water and Blood Plasma."  Science,      75 (1975).
128.   Dowty, B., and Laseter, J. L., "A Gas Chromatographic Procedure to
            Monitor Low Molecular Weight Volatile Organics Introduced
            During Municipal Water Processing."  Anal. Letters, 8, 25  (1975).
129.   Dowty, B. J., et_ al_. , "New Orleans Drinking Water Sources Tested by
            Gas Chromatography-Mass Spectrometry."  Environ . Sci. Techno!.,
               762 (1975).
130.   Stevens, A. A., et. al_. , "Chlorination of Organics in Drinking Water."
            Presented at the Conference on the Environmental Impact of Water
            Chlorination, October 22-2U, 1975, at Oak Ridge National Laboratory,
            Oak Ridge, Tenn.  Proceedings to be published.

131.   Pereira, N. C., et_ al . , "The Prediction of Free Residual Chlorine
            Concentrations in a Flowing Stream."  Calspan Corporation,
            Rept. No. ND-5358-M-1, Buffalo, N.Y. (197M.

132.   Draley, J. E. , "Chlorination Experiments at the John E. Amos Plant
            of the Appalachian Power Company: April 9-10, 1973."  Argonne
            National Laboratory, Rept. No. ANL/ES-23 Environmental and
            Earth Sciences, Argonne, 111. (June 1973).

133.   Lietzke, M. H. , "A Kinetic Model for Predicting the Composition of
            Chlorinated Water Discharged from Power Plant Cooling Systems."
            Presented at the Conference on the Environmental Impact of Water
            Chlorination, October 22-2U, 1975, at Oak Ridge National Laboratory,
            Oak Ridge, Tenn.  Proceedings to be published.

13^.   Nelson, G. R. , "Predicting and Controlling Residual Chlorine in
            Cooling Tower Slowdown."  U.S. Environmental Protection Agency,
            Environmental Protection Technology Series EPA-R2-73-273,
            Corvallis, Oreg. (July 1973).

135-   Manabe, R. M. , "Measurement of Residual Chlorine Levels in Cooling
            Water — Amperometric Method."  U.S. Environmental Protection
            Agency, Corvallis, Oreg.  Environmental Protection Technology
            Series EPA 660/2-73-039  (August 197*0.

136.   Marinenko, G. , "Electrochemical Flux Chlorine Monitors."  In "Technology
            and Ecological Effects of Biofouling Control Procedures at Thermal
            Power Plant Cooling Water Systems (Lor en J). Jensen, editor)."
            Proceedings of a Workshop held at The Johns Hopkins University,
            June 16-17, 1975.  Ecological Analysts, Inc., Wantagh, N.Y.
            (February 1976).

137.   Marinenko, G. , _et_ al_. , "An Instrument with Internal Calibration for
            Monitoring Chlorine Residuals in Natural Waters."  Jour. Fish. Res.
            M- Can.., J33j 822 (1976).

138.   Johnson, J. D., "Measurement and Persistence of Chlorine Residuals in
            Natural Waters."  Presented at the Conference on the Environmental
            Impact of Water Chlorination, October 22-2U, 1975, at Oak Ridge
            National Laboratory, Oak Ridge, Tenn. Proceedings to be published.

                                      1*3

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139-  Terlecky, P. M. , Jr., _et_ ajL. , "Water Pollution Investigation:  Ashtabula
           Area."  U.S. Environmental Protection Agency, Great Lakes Initiative
           Contract Program, National Technical Information Service, Springfield,
           Va., Rept. No. EPA-905/9-7I+-008 (January 1975).

ihO.  Eaton, J. W. , _et_ aJ^. , "Chlorinated Urban Water:  A Cause of Dialysis-
           Induced Hemolytic Anemia."  Science, l8l, k63 (19731.

lUl.  Grothe, D. R. , and Eaton, J. W. , "Chlorine-Induced Mortality  in Fish."
           Trans . Amer. Fish. Soc., JL, 800 (1975).

      Gregg, B. C. , and Heath, A. G. , "A Method for Intermittent Chlorine
           Dosing in Continuous-Flow Toxicity Tests."  Bull. Environ.
           Contain. Toxicol., J^,  588 (.1975).
      Cairns, J. , Jr., _et_ al . , "Temperature Influence  on Chemical Toxicity
           to Aquatic Organisms."  Jour . Water Poll. Control Fed. , j£jk  267
           (1975).

ikh.  Cairns, J., Jr., _et_ al . , "The Effects of Temperature Upon  the Toxicity
           of Chemicals to Aquatic Organisms."  Hydrobiologia , Jj£» 135  (1975).
      Katz, B. M. , "Physiological Actions of Low Concentrations  of Chlorine
           to the Mosquito Fish Gambusia af finis."  Master  of  Science Thesis,
           Florida Institute of Technology, Melbourne, Fla.  (.1975).

      Buckley, J. A., et_ aJL. , "Changes in Blood Chemistry and  Blood  Cell
           Morphology in Coho Salmon  (Oncorhynchus kisutch) Following
           Exposure to Sublethal Levels of Total Residual Chlorine in
           Municipal Wastewater."  Jour . Fish. Res. Bd.  Can. , J2,, 776  (1976).
      Basch, R. E. , and Truchan, J. G.,  "Calculated Residual  Chlorine
           Concentrations Safe for Fish."  Michigan Water Resources  Commission,
           Bureau  of Water Management, Department  of Natural  Resources,
           Technical Bulletin 7*t-2, Lansing, Mich.  (September 197U).

148.  National Academy of Sciences, "Water Quality Criteria 1972."   U.S.
           Environmental Protection Agency, Washington,  D.C., Ecological
           Research Series EPA-R3-73-033 (1973).

lH9.  European Inland Fisheries Advisory Commission, "Report  on Chlorine
           and Freshwater Fish."  In  "Water Quality Criteria  for European
           Freshwater Fish."  European Inland  Fisheries  Advisory Commission,
           Food and Agriculture Organization of the United Nations,  EIFAC
           Technical Paper No. 20, Rome, Italy (1973).

150.  Arthur, J. W. , and Eaton, J. G., "Chloramine Toxicity to the Amphipod
           Gammarus pseudolimnaeus and the Fathead Minnow  (Pimephales  promelas ) . "
           Jour. Fish. Res. Bd. Can., £8j l8Ul (1971).
151.  Mount, D.  I.,  and Stephan,  C. E. ,  "A Method  for  Establishing Acceptable
           Toxicant  Limits  for Fish — Malathion  and the Butoxyethanol Ester
           of 2,U-D."  Trans. Amer. Fish. Soc.. , JJ6,  185 (1967).

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152.  U.S. Environmental Protection Agency, "Quality Criteria for Water."
           U.S. Environmental Protection Agency, Washington, D.C.
           (February 1975).

153.  Federal Register, "Part IV:  Secondary Treatment Information—
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           Task Force Report, U.S. Environmental Protection Agency,
           Washington, D.C.  (July 1975).

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                                   TECHNICAL REPORT DATA
                            (Please read Instructions on the reverse before completing)
1. REPORT NO.,
 EPA-600/3-76-098
                                                           3. RECIPIENT'S ACCESSION NO.
4. TITLE AND SUBTITLE
 EFFECTS  OF WASTEWATER AND COOLING WATER  CHLORINATION
 ON AQUATIC LIFE
             5. REPORT DATE
               August  1976 (issuing Date)
                                                           6. PERFORMING ORGANIZATION CODE
7. AUTHOR(S)
                                                           8. PERFORMING ORGANIZATION REPORT NO.
 William A.  Brungs
9. PERFORMING ORGANIZATION NAME AND ADDRESS
 Environmental Research Laboratory
 U.S. Environmental Protection Agency
 6201 Congdon Boulevard
 Duluth, Minnesota  5580U
             10. PROGRAM ELEMENT NO.
               1BA608
             11. CONTRACT/GRANT NO.
12. SPONSORING AGENCY NAME AND ADDRESS
 Environmental Research Laboratory
 Office of Research and Development
 U.S. Environmental Protection Agency
 Duluth, Minnesota
             13. TYPE OF REPORT AND PERIOD COVERED
               Literature Review
             14. SPONSORING AGENCY CODE
               EPA-ORD
15. SUPPLEMENTARY NOTES
16. ABSTRACT
      The  literature since 1972 pertaining to waste-water and cooling  water chlorination
 is discussed under the following headings:   review papers, chlorinated municipal
 wastewaters, continuously chlorinated water, intermittently chlorinated water,
 dechlorination,  avoidance, formation of chlorinated organic compounds, aquatic life
 criteria  and application factors, and regulations.
      Field and laboratory research results support a single criterion of 0.003 mg/1
 for continuous exposure of freshwater organisms.  The former distinction between
 warmwater and coldwater systems is no longer appropriate; recent  data indicate
 that several freshwater fish species are as sensitive as trout  and salmon.
      The  present concern for the formation of chlorinated organics in water and
 wastewaters is justifiable and the greatest present need is to  determine the
 ecological significance, if any, of these results.  The future  course of wastewater
 chlorination will be greatly influenced by the recent proposed  changes in the
 Environmental Protection Agency's regulations on secondary treatment.  The changes
 intend  that disinfection only be considered when public health  hazards need to be
 controlled, and that the exclusive use  of chlorine should not be  considered where
 protection of aquatic life is of primary consideration.  Where  these uses co-exist,
 alternate means of disinfection must be considered.
17.
                                KEY WORDS AND DOCUMENT ANALYSIS
                  DESCRIPTORS
                             COS AT I Field/Group
 Aquatic  animals
 Aquatic  plants
 Bioassay
 Biocides
 Bromination
 Bromine  halides
 Chlorination
Condenser tubes
Cooling towers
Cooling water
Dechlorination
Disinfectants
Disinfection
Fishes
DESCRIPTORS  (continued)
 Fouling prevention
 Ozone
 Ozonization
 Sewage
 Sewage treatment
     r*n1 nc
                            6c, 6F, 6l
                            6T, 7B, 7C
                                                      igy
                                                      rcu
18. DISTRIBUTION STATEMENT
 RELEASE  TO PUBLIC
                                              19. SECURITY CLASS (ThisReport)
                                                UNCLASSIFIED
                           21. NO. OF PAGES
                                32
                                              20. SECURITY CLASS (Thispage)
                                                UNCLASSIFIED
                                                                        22. PRICE
EPA Form 2220-1 (9-73)
                                                      . GOVESNMENT PRINTING OFFICE: 1976-657-695/5W9 Region No. 5-M

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