DISINFECTION
           OF

 WASTEWATER
  TASK FORCE REPORT

        JULY 1975
   U.S. ENVIRONMENTAL PROTECTION AGENCY
    Office of Reasearch and Development
       Washington, D.C. 20460


-------
       TASK FORCE REPORT
          DISINFECTION

               of

          WASTEWATER
  ENVIRONMENTAL PROTECTION AGENCY
OFFICE OF RESEARCH AND DEVELOPMENT

-------
               SECTION VII - ACKNOWLEDGEMENTS

    The following personnel from' the Office of Research and Development
contributed to the preparation of the Task Force Report:

Office of Environmental Engineering
   Municipal Pollution Control Division

     William A.. Rosenkranz
     James V.  Basilico
     Edward J. Opajtken

NERC,  Cincinnati
   Advanced Waste Treatment Research Laboratory

     Cecil Chambers

Office of Environmental Science
   Ecological Processes and Effects Division

     Frank G. Wilkes

   Water Supply Resiearch Division

     Hend Gorchev

NERC,  Corvallis
   National Water Quality Laboratory, Duluth,  Minnesota

     William A. Brjungs
     William P. Dalvis

   National Marine Water Quality Laboratory,  Naragansett, Rhode Island

      Victor Cabelli.

-------
                         CONTENTS
Section                      Title                                Page
 I                 Summary                                      1
 II                Conclusions and Recommendations               3
 III                Introduction                                    6
 IV                Public Health Effects                           8
 V                Effects of Disinfectants on Aquatic Life          13
 VI                Disinfection Process Alternatives               21
 VII               Appendices
                     A.  Research and Development Projects       41
                     B.  State Standards (Existing)                 43
                     C.  Public Health Effects Tables and figures   44
                     D.  References                              51

-------
                       SECTION I - SUMMARY
Task Force Origin

   An intra-agency Task Force was formed in early 1974 lo develop the neces-
sary background information for consideration of ogency policy on wastewater
disinfection requirements and the use of chlorine.   During that time the major
consideration of the Task Force.w.as. the need for universal year-round dis-
infection and  whether  the  present  secondary  treatment regulation should  be
modified to allow  flexibility.  Since the input to the final report would originate
from ORD personnel, ORU was requested by the Deputy Assistant Administrator
for Water Programs, OWPO, onDecemberS,  1S'74,  to assume the responsibility
of completing the Task Force report. .

Objective of the Task Force

   The main  objective of ihcOHD Disinfection PC licy Task Force was to provide
information in the form of  guidance on public he ilth and water quality require-
ments,  the  potential toxic effects of chlorination to'both the aquatic and human
environments and  alternate methods  for  disinfection.  More  specifically  the
Task Force objective was to prepare a summajy report for use by  the Office
of Water Programs Operations in dealing with thi  chlorine issue and in planning
disinfection policy regarding the need to revise the disinfection requirements
to meet secondary treatment regulations.

Summary

   The members of the  Task Force have objectively reviewed all  aspects of
wastewater disinfection with regards to public health and water quality require-
ments,  toxic  effects and availability of alternate processes.   As a result of
this review the Task Force findings may be highlighted as follows:

      1. Disinfection of  sewage effluents docs provide  an  effective means of
          reducing to a sale level the hazards of infectious disease in receiving
         waters.  The  requirements for disinfection are based on public health
         considerations and have greatly  reduced waterborne disease outbreaks.
         Under certain circumstances and locations  such as high dilution and"
         die off,  seasonal recreation,  and no downstream reuse potential,  the
         benefits of disinfection for protection of  public health are minimized
         and  may not be needed.  The reaction by-products of certain disinfec-
         tants have been identified with potential health hazards;  these  proper-
         ties must be considered when disinfection is practiced.

-------
2*  The toxic effects of total  residual .chlorine on  fresh water organisms
    have been further confirmed at very low concentrations. Dechlorina-
    tion greatly reduces or eliminates  the  toxicity caused by residual ch-
    lorine, its effect on reducing chlorinated organics is not known.  Bro-
    minated effluent may be as toxic as chlorinated effluent, but its toxicity
    is reduced to no-effect concentrations in a  much  shorter period  of
    time than  chlorinated  effluent (minutes instead  of hours).  No  acute
    adverse effects  from  ozonated effluents  were observed.   There  is
    limited  information  on the  effects of chlorine  residuals on marine
    and estuarine life.

3.,  There are satisfactory alternate disinfection processes'that  could be
    substituted in place of cisiorination; Results  have shown that dechlor-
    ination is  effective in reducing the toxic effects associated with  resi-
    dual combined chloriae.Ozone is an effective disinfectant when applied
    to tertiary treated effluents, Bromine chloride is an effective disinfec-
    tant on   secondary effluent with less toxic effects  than chlorine  to
    aquatic  life.   Recent improvements  in ultraviolet light  disinfection
    equipment design gives this process improved potential for wastewater
    application.

-------
         SECTION II CONCLUSIONS and RECOMMENDATIONS

Conclusions

    The Task  Force believes that the disinfection of wastewater  for  pathogen
destruction is of obvious public health importance since these organisms,  if not
destroyed, could be transmitted to man through  sewage contamination of water
for drinking, food processing,  irrigation,  shellfish culture or recreational pur-
poses. However the application of disinfection regulations should be periodically
updated to take advantage of  new  findings  and  technology  in  order that EPA
make prudent and  efficient use  of our  nation's resources in administering the
secondary treatment  regulations.    There  are  a number  of conclusions that
can be made from  this Task Force report that would help to support new policy
decisions on disinfection.   These conclusions  are listed in the discussion that
follows.

  1.  Disinfection of wastewaters is needed for protecting the public health when
      the receiving water is used for water supply, recreation,  irrigation, etc.
      Although disinfection of drinking water is an essential  step for protecting
      public health, the disinfection of  wastewaters should more appropriately
      be decided on a case-by-case basis  taking into consideration the effects
      of  wastewater disposal practice on the different water uses.

  2.  Chlorine is currently the predominant wastewater disinfectant  and it is
      essentially the exclusive disinfectant if one includes its counterpart,  sod-
      ium hypochlorite.  Disinfection of secondary effluents with  chlorine .can
      reliably  meet the present bacteriological standards for secondary treat-
      ment.

  3.  Disinfection of water and wastewater with chlorine can result in the forma-
      tion of halogenated  organic compounds that are potentially toxic  to man.

  4.  Disinfection of wastewaters with chlorine can result in a residual chlorine
      level that is  toxic  to fish.   Although  additional research needs  to be
      conducted, available  data indicate  that  chlorine concentrations  below,
      0. 01 mg/1  and 0.002 mg/1 have no adverse effects on warm water and
      cold water fish respectively.

         Available data, though limited, indicate that chlorine at concentrations
      in excess of  0.01 mg/1  poses a serious hazard to marine and estuarine
      life. Additional study of many organism types under a wide variety of
      environmental   conditions is needed to  establish  definitive  criteria for
      chlorine,

  5.  Dechlorination with  suflur dioxide is practiced  at full  scale  facilities
      where chlorine residuals must be  eliminated.   Although no criteria for
      dechlorination chemicals can be proposed at this time, no adverse acute
      effects were  observed on fish following dechlorination with sulfur dioxide.

-------
  6.  Dechlorination with carbon is feasible but costly.  Additional research
      is required to provide accurate cost and  operating data.   Health effects
      research is also required to establish if  carbon is effective for removing
      the potentially toxic compounds formed during chlorination.

  7.  Ozone is finding acceptance at a few full scale plants.  As of now, secon-
      dary effluents will  require filtration as a  tertiary  treatment  stage  to
      consistently meet the fecal coliform standard (200 fecal coliforms/100 ml)
      with ozonation.   No criteria  can  be  estimated  as yet for ozone although
      data on fish toxicity indicate that the effluent disinfected with ozone is less
      toxic than with chlorinated effluent.

  8.  Bromine chloride  is  the newest  disinfectant  in the  field of alternates.
      It is an  effective disinfectant for secondary effluents and  it is less toxic
      to aquatic life than chlorine.  Health effects are unknown.

  9.  Although ultraviolet light has not been: widely used to disinfect wastewater,
      there is  limited information  that indicates  it may become  a potentially
      desirable alternative.   It is the  only physical process whereas all the
      other disinfectants are chemical processes.  On-going research will pro-
      vide  answers as to its applicability to adequately disinfect wastewater.

Recommendations

    The Task Force feels that when disinfection standards are set,  the interests
of human  health have to  be  considered paramount. As with all environmental
decisions,  we may still have  to consider a trade-off of values in which it may
be necessary  to compromise the optimum natural  ecology of limited stretches
of receiving waters to the greater interest of protecting human life.

    The basis for establishment of disinfection standards has  been subject to
controversy  for many years.  The summary of the  states'  disinfection regula-
tions show many  different  requirements and further  compounds  the issue of
uniform secondary treatment standards. In view of the many factors presented
in this report and considered by the  Task Force, the following recommendations
are made;

  1«  Disinfection  of wastewaters is needed to protect public health where the
      receiving waters are used for purposes such as down stream water supply,
      recreation,  irrigation,  shellfish harvesting, etc.

  2.  Modify  the present standards and regulations for disinfection in order to
      allow flexibility in regard to year-round  requirements. Also where it can
      be demonstrated that the protection of public  health is not involved addi-
      tional flexibility should be allowed in the consideration of across the board
      disinfection. Criteria should be developed for these areas.

-------
3.  The exclusive use of chlorine  for  disinfection should not be continued
   where protection of aquatic life is of primary consideration.   However
   when chlorine is used,  the total residual chlorine in the receiving waters
   should not exceed  the  recommended levels  outside a  described mixing
   zone.  Use  of  alternate processes should be  encouraged by  the agency
   through a vigorous promotion of the new alternates.               '

4.  The use of alternate disinfectants should  be further  pursued because of
   recent findings of the potentially hazardous halogenated organics in drink-
   ing water.

-------
                  SECTION III - INTRODUCTION

BACKGROUND

   Prior to the enactment of P. L.  92-500, domestic wastewater disinfection
practice was,  for the most part, controlled locally by the States.  Disinfection
requirements were based on water..quality standards and/or specific disinfection
criteria which applied to the discharge of wastewater.  Implementation of disin-
fection   policy through  the States  generally resulted in flexible requirements
which  were related to the protection of public  health.  Seasonal disinfection of
wastewater was practiced in many Stales, while no disinfection was required for
certain wastewaters where such a discharge did  not endanger public health.  The
present regulations  require continuous  disinfection of  all domestic wastewater
on the basis that disinfection is an "important element of secondary  treatment
which is necessary for protection of public health." The selection of  the disin-
fection process to meet the fecal colitorm-limitations was limited to chlorination
since it was  the only wastewater disinfection process available for widespread
use by municipal wastewater treatment plants.  The net result was EPA policy
in conjunction with available disinfection technology encouraged the use of chlo-
rination.

   Before the enactment of P. L., 92-500, little consideration was given to poss-
ible effects that indiscriminate use  of chlorine might have on fish and other aqua-
tic organisms. These adverse effects were  clearly brought out in a memorandum
"Problems with  Chlorination of Effluents",  August  24,  1970, to the Federal
Water  Quality Administration Commissioner from the National Water Quality
Laboratory,  Duluth,  Minnesota..  However  the cost,  reliability and potential
impact of the alternative disinfectants  were questionable at that time to adopt
a  significant change in FWQA1 s position with respect to disinfection techniques.
Also at that  time,  the  formation  of halogenated   organics  and other reaction
by-products was  recognized but  the extent and magnitude was not quantitatively
defined. Only recently, through improvements in analytical  techniques and the
public  concern for drinking  water quality, has the potential health  hazard of
halogenated organics been brought  out.

   An R&D program was  approved  for implementation to develop disinfection
alternatives  and  the necessary    bioassay support work.  Consistent with the
state-of-the-art  at that time, emphasis was put on further  developing the de-
chlorination and  ozonation processes as the likely candidates that could supple-
ment chlorination.

    Top priority was given  to the need for  developing new alternatives to chlor-
ination. The grant  with the  City of Wyoming,   Michigan,   is the major part
of this  program.  Although the project  is  only  50% completed it has produced
significant results and  has  shown that dechlorination,  ozonation and bromine
chloride are effective processes with lesser toxic effects than chlorine.  Recent
improvements in UV equipment design gives  this process  greater potential to
wastewater applications, especially for small plants.

-------
    Additional bioassay information on chlorine  toxicity and new  bioassay data
on dechlorination, ozone and bromine chloride have been obtained.  Some defini-
tive water quality criteria for these disinfectants are being develop* d but addi-
tional work  is needed.

    A national survey is  being conducted in order to determine  the formation
of halogenated organics  through disinfection of water  supplies.   Samples will
be collected from some 80 water supply systems and halogenated organics deter-
mined before and after chlorination.

    Research is in progress to provide the data base required for the  develop-
ment of recreational water quality criteria.  Epidemiological-microbiological
studies  are being conducted  at several  bathing  beaches in order  to correlate
incidence of diseases among swimmers  to some microbial indicators of pollu-
tion.  The currently accepted fecal limit  for recreational waters will be  re-
evaluated in light of new findings.   This,  in  turn, will decide the extent of
wastewater  disinfection if recreational  waters  are to be  safe for the public.

    The following sections discuss the present status and highlights the research
findings on public health effects, the effects of disinfectants on aquatic  life,  and
alternative  disinfection processes.

-------
          SECTION IV - PUBLIC HEALTH EFFECTS
Rationale for Disinfection

   A variety of infectious microorganisms are found in the feces of active
cases or carriers and, hence,  in  municipal wastewaters  containing the
fecal wastes from such individuals*  Included are salmonellae,  shigellae,
enteropathogenic Escherichia coli,  Pseudomanas aeruginosa and a variety
of enteric viruses^including  hepatitis (1)1   Furthermore,  outbreaks of
gastroenteritis, typhoid,  shigeilosis, salmonellosis.  ear infections due to
Psendpmonas aeruginosa, and infectious  hepatitis  have been reported a-
mohg individuals drinking or swunming  in  sewage contaminated waters
or consuming raw molluscan shellfish harvested therefrom (2-7).

   The range and densities of pathogens in municipal waste water effluents
are,,  of course,  dependent on the  number of active  cases  and carriers
in the discharging population at any given time.  However, even if it  were
practical to monitor  raw sewage for the variety of potential pathogens
therein,  good public health practice requires the assumption of their pre-
sence in sufficient numbers to produce a reasonable probability of disease
even when small quantities  of sewage are injested.   The obvious solution
to this problem is  to reduce the  pathogen  density in the target waters
receiving municipal wastewaters so that the probability of "contact" with an
infective dose  of a particular pathogen is reduced below some acceptable
limit.   From  experience and  judgment, this limit  has been associated
with a median fecal coliform density of 14 fecal coliforms or 70 total  coli-
forms per  100  ml  in shellfish  growing  waters (8,9).   From a limited
quantity of  epidemiological data,  it has been  associated with 200  fecal
coliforms per  100 ml in primary  contact  recreational waters  (10,11).
For  raw surface waters to be  used  as water  supply sources and receiving
conventional treatment,  the National Academy of Sciences recommenda-
tion  is to limit the geometric means of fecal coliform concentrations to
2,000 per 100 ml (12).

    The above  water  quality criteria can be achieved by the physical re-
moval or chemical  destruction{disinfecticm)of the pathogens and indicator
microorganisms  at   the  source or their  dilution together with natural
die-away in transit to the  target. Primary and secondary treatment sys-
tems were not  designed for nor are they particularly effective in  reducing
xnicrobial densities in wastewaters.  Their  effectiveness as reported in
the literature  varies  w-ith the organisms being studied,  the type  of treat-
ment and the  operative conditons during the study (13-15).   In  general,
the combined  effect of primary  and secondary treatment does  not reduce
pathogenic bacteria and viruses or indicator bacteria more than 90 per-
cent. However, the effectiveness of disinfection is enhanced  by the re-
moval of solids and nutrients during treatment.

                                   8

-------
Benefits of Disinfection

    Chemical  disinfection  of  waste-waters using chlorine is  an effective
means of reducing the density of pathogenic and indicator bacteria provided
that solids and interfering materials are  reduced by preliminary treat-
ment,  residual chlorine levels are maintained  and the contact time is
su fficiently long.  Reductions of 99. 9 to 99 percent have been reported
with salmonellae and  coliform bacteria (16, 17).  Velz (18) notes that it
is feasible to  achieve and maintain a residual  coliform bacterial density
of 500/100 ml,  representing an efficiency  of 99. 995 percent.   Bromine
chloride (19)  and  ozone  (20)  are reported to be  as  or more effective
than chlorine.

   In general, enteroviruses  such  as poliovirus, coxsackie, etc., appear
to be more resistant than bacteria to chemical disinfectants such as chlor-
ine, although  the  sensitivity  varies considerably by species,  type,  and
even strain.  Kelly  and  Sanderson  (21) found  a greater  than 99 percent
kill of  polio virus  at residual  chlorine  levels at 0.1 to 0. 3  mg/1 with
a  2 minute contact time.  Clarke,  et al.  (22)  reported  a 99 percent kill
of adenovirus  with  0. 1 mg/1 HOC1 In r2~ seconds.  At the same concentra-
tion of hypochlorous acid,  a 99 percent kill of poliovirus 1 and coxsackie
virus A2 were attained  in 8  minutes  and  40 minutes respectively. Shuval
et al. (23) in  their  study  of the effects of chlorination on trickling filter
effluents,  reported that residual  chlorine at 3 mg/1 with  a  30 minute
contact time killed  99 percent of Echo 9 virus and 50 percent of poliovirus
I.   Bromine chloride was reported to be more  effective  than chlorine for
the destruction of poliovirus II (19).

    The introduction of chlorine in  the early 1900's for the disinfection of
water supplies resulted  in a  dramatic decline in waterborne disease out-
breaks.  Major cholera and typhoid epidemics attributable to contaminated
water supplies are a thing  of the past.  Craun and McCabe noted that from
1951 to 1970  about fourteen waterborne disease outbreaks occurred each
year in  the United States  (24).   However, for 1971  and 1972  the rate
has increased to   an average  of 24  outbreaks per yg'ar.  Most  common
causes of these outbreaks  are: lack of disinfection of groundwater, break-
down of chlorination equipment,  cross-connections (25).

    In both the shigella (3)   and salmonella (2) outbreaks of swimming as-
sociated illness,  there  appears to  have been a breakdown in wastewater
treatment.  In addition, a number of the reported outbreaks of shellfish
associated infectious hepatitis appear to  be associated with the presence
of raw sewage (26).   Therefore, it would seem that proper disinfection
superimposed on secondary or tertiary treatment does render waste water
effluents  safe for  discharge  into recreational and shellfish  waters when
a prohibited zone is maintained in the "shadow" of an effluent outfall.

-------
Need for Disinfection

   Disinfection of effluent from a given source is required whenever the
processes  of physical removal at  the source and dilution during transit
to the target  are not sufficient to meet the target area requirements as
stated below.

Standards Required

   At the present time,  a realistic standard for disinfection can be stated
as follows:  The disinfection of wastewater must meet the standards for
indicator microorganisms when the  receiving  stream is used for water
supply recreation and shellfish growing areas.

   Obviously, the above definition "is not fixedin concrete".  As advanced
methods for  pathogen removal become available and better  (in terms of
logistics,  economics, ecological and health side effcts) disinfectants are
developed, the removal,  disinfection and dilution can be treated as sep-
arate barrier layers in wastewater disposal and reuse. Even then it would
seem judicious to prohibit water users in the immediate vicinity (in time or
space) of wastewater outfalls.

Conditions for  Exemption

   Exemptions to the requirement for disinfection occur when natural die-
away and a dilution are adequate for meeting the target area requirements
or during those times whenthere is not potential for adverse health effects;
e. g., no swimming, due to cold  weather.  The  former case  has been
operative at  some sewage  treatment plants  along  the  coast of Southern
California which  use long  distance,  deep ocean outfalls (27-29).  The
latter exception has  been taken by communities  such as New York City
which chlorinate only during the swimming season (30).
Toxic Effects of Disinfectants
1.  Residual and Raction Products

    a. Chlorine

    It has recently been reported that chlorination of water and wastewater
results in the formation of halogenated organic compounds that  are sus-
pected of being toxic to man.

    In his pioneer study, Jolley (31) determined that under experimental
conditions   approximating   those  encountered in wastewater treatment
plants,  chlorine-containing organic compounds are present  after  chlorin-
ation of the effluent. Some seventeen chlorine-containing, stable  organic
compounds were identified  and quantified at the 0. 2 to 4. 3 ug/1 level.
A list of  these chlorination  products and their concentrations is given in
Table I.
                                   10

-------
    Under EPA contract,  Eco-Control (32)   reviewed the literature  for
health hazards associated with these compounds or classes of compounds.
Compounds   listed in Table I fall under  the general classification of
(1)  chlorophenols,  (2)   chlorobenzoic and  chlorophenylacetic acids and
(3)  chlorinated purines and pyrimidines.  It was  concluded that  although
the first two classes of compounds should not represent significant health
hazards  at those  concentrations, the chlorinated  purines and pyrimidines
could potentially  exhibit some teratogenic and carcinogenic activities.

    Bellar et  al .(33)  determined the nature and concentrations of organo-
chlorine compounds in the effluent of a wastewater  treatment plant re-
ceiving a mixture of domestic sewage and industrial wastes. Based on the
results presented in Table II,  Bellar et al.  concluded that the  increase
in chloroform  concentration appears to~~Be due to chlorination.  Similar
conclusions could not be reached for the other compounds listed because of
small differences in the concentration levels before and after chlorination.

    During the chlorine disinfection of municipal water supplies,  Bellar
et al  (33) found chloroform, bromodichloromethane,  and dibromochloro-
methane and assumed that these compounds are formed through the inter-
action of chlorine with organic compounds in  drinking water.  Table III
lists  the concentration found at different sampling points of a water treat-
ment plant (see Figure 1).

    Rook (34) found the following compounds to be formed by chlorination
of water  supplies:   chloroform, bromodichlorometane, dibromochloro-
methane, and bromoform. He further postulated that naturally occurring
humic substances are precursors  to the formation of these haloforms.
The maximum concentrations found were: chloroform  554 ug/1, bromo-
dichloromethane    20.0 ug/1,   dibromochloromethane   13.3 ug/1,  and
bromoformlO. 0 ug/1.

    A cursory evaluation of the  health effects of some of these  compounds
was given by Kraybill (35) and is presented in  Table IV. It can be seen
that both bromoform and  chlorodibromomethane, which are presumably
formed  during  disinfection  with  chlorine,   are classified as  "suspect
carcinogens"

    A multitude of halogen-containing organic compounds has been found in
water and wastewaters (36). Example of such compounds found  in drinking
water is given in  Table V presented byMcCabe and Tardiff (37). However,
these compounds are not specifically mentioned here since there  is yet no
evidence indicating the in-situ formation of these halogenated  compounds
through  the  interaction of chlorine with organic compounds  in  water or
wastewater.

    b. Dechlorination

    Dechlorination can be effected  using reducing agents such  as sulfur
dioxide,  sodium bisulfite,  or sodium sulfite, activated carbon or  by aera-
tion for  certain volatile forms of chlorine.

                                   11

-------
    Free chlorine (HOC1  and OC1) and  inorganic  chloramines are known
to.be destroyed by sulfites and activated carbon (38, 39).

    There is a need to evaluate the literature and perhaps conduct research
to determine  the interaction of halogenated organics such as chloroform
with de.chlorinating agents of the types mentioned  above.   Until  more is
known on this subject, it cannot be  stated with any  certainty that con-
ventional dechlorinating agents will efficiently remove halogen-containing
organics.

    c.  Ozone

    Ozone is used extensively in Europe  for  the disinfection of  drinking
water.  Little is known  of the  toxicity of  ozone in aqueous solutions,  its
interaction  with  organic  matter  in water and  wastewater and the acute
and chronic health effects  of the reaction by-products. Additional research
is needed in  this area before  large  scale use of ozone  as a substitute
for chlorine disinfection is pursued on a wide  scale.

    d.  Other Disinfectants

    Bromine,  bromine chloride, chlorine dioxide, iodine, permangate,
silver, ultraviolet light have iaeen used  to a limited extent for disinfection
purposes.  Permanganate and -silver  have no  known application in waste-
waters.  Drawbacks for the above include: high cast,  toxic side effects,
inefficiency under  turbid conditions, and lack of residual disinfection.
The halogen disinfectants (Br ,  BrCl,  I ) will probably  exhibit similar
properties to chlorine in their interaction with organic compounds  in water
and wastewaters. Considerable work  is needed to evaluate both the short-
and  long-term  toxicities of these disinfectants and  their reaction pro-
ducts.
                                    12

-------
      SECTION V.  EFFECTS OF DISINFECTANTS ON AQUATIC LIFE
INTRODUCTION

    The present emphasis on environmental preservation and human health
is resulting in an increased  use of chlorine for disinfection and waste treat-
ment.  Re cent investigations, including life-cycle studies with aquatic organ-
isms,  have greatly clarified the  significance  of  chlorine toxicity.  Several
major projects  in  various stages  of  development or  completion will  add to
this understanding,  but  sufficient  data are available to permit estimates of
the maximum levels of total residual  chlorine (TRC)  which if not exceeded
would result in protection of aquatic life.

    As with all toxic materials, it is essential  to consider potential environ-
mental and  chemical effects of toxicity.  Merkens (1)  states that the toxicity
of chlorinated wastes in rivers will depend not only on  the amount of chlorine
added but on the concentration  of TRC  remaining in solution.   He also con-
cluded that  the  toxicity of  TRC will depend on  the relative proportions of
free chlorine and chloramines.   This  ratio in turn depends  on  the amount
of ammonia  originally present  in  the  water,  the amount of chlorine added,
pH,  temperature,  and the  length  of time over which the reaction has  taken
place.  This study  also concluded that  free chlorine is more toxic than  chlor-
amines and that TRC is  more  toxic  at lower  pH (6.3 versus 7.0) because
more free chlorine is present at the lower pH.  Merkens concluded, however,
that "the toxicity  of the solution  is  determined in the main by  the  total
concentration of available chlorine and that the toxicities of the chloramines
and free  chlorine  must all  be  of the same order."  Doudoroff and Katz  (2)
also stated  that the difference  between the toxicity to fish of free chlorine
and chloramines is apparently not very great.
FRESHWATER

1.  Effects of chlorinated wastewater treatment plant effluent.

    The Michigan  Department of Natural Resources  (3) reported the effects
on'caged fish in  several receiving  streams below wastewater  discharges.
Fifty percent of the rainbow  trout  died  with  96  hr.  (96-hr TL50) at TRC
concentrations of 0.014 to 0.029 mg/1; some fish died as  far as  0.8 mile
(1. 3 km) below the outfall.  These same discharges were studied when chlor-
ination was temporarily interrupted and no mortality was observed.

    Tsai (4)  studied the effects on fish of 156 wastewater treatment plants  in
Maryland,  northern Virginia,  and southeastern Pennsylvania.  All the plants
discharged chlorinated municipal wastes into small streams containing fish .
Inmost  of the  plants  in Maryland  and Virginia 0.5 to 2.0 mg/1 residual


                                     13

-------
chlorine is  maintained in  the  effluents.   Pennsylvania  requires  0. 5 mg/1
in effluents prior to discharge  to natural surface water.  Tsai studied prin-
cipally fish,  but observed typically a clean bottom without living organisms
in the area immediately below  the chlorinated outfalls.  Unchlorinated dis-
charge areas were typically characterized by abundant growths of wastewater
fungi.   No  fish  were  found in water with  a TRC  above 0.37 mg/1,  and
the species  diversity  index reached zero  at  0. 25 mg/1.   A 50%  reduction
in species diversity index occurred  at 0.10 mg/1.  Of the 45  species of fish
observed in the study areas,  the brook  trout  and brown trout  were the
most sensitive and were not found  at  concentrations  above approximately
0.02 mg/1.  Ten species were not found above 0.05 mg/1.

    Arthur et  al. (5) studied the effect of  chlorinated secondary wastewater
treatment pTanT effluent containing only  domestic sewage effluent  on  repro-
duction of fathead minnows,  Dapfania magna,  and the  scud Gammarus pae-
udolimnaeus.    D.  magna  apparently was the more sensitive invertebrate
species and died at  a  TRC concentration of 0. 014  mg/1.   Successful  repro-
duction occurred at 0.003 mg/1 and: below.  Scud reproduction was reduced
at concentrations above approximately  0.012  mg/1 (1.2  percent  effluent).
No effects  on any life cycle stage,  including reproduction,  of the  fathead
minnow was observed  at a concentration of 0.014 mg/1; adverse effects were
observed: at 0.042 mg/1.   Acute toxicity studies with eight species of fish,
crayfish (Or c on e ct e s virilis),   scud  (Gammarus  pseudolimnaeus),   snails
(Phyaa Integra and Campeloma decisum),and stoneflies  (Acroneuria lyco-
rias) indicated' that  the crayfishv  snails,  and caddisfly  larvae were least
sensitive (7-day TL50 values greater than 0.55  mg/1).  Seven-day TL5Q
values for the other organisms were between 0.083 and 0.261 mg/1; coho
salmon and  brook trout were the most sensitive.  Nearly 50 percent of these
observed mortalities occurred  in the first 12 hr of the acute  tests  indicating
that the lethal effect of TRC occurs rapidly.

    Esvelt et  al. (6, 7)  and Krock and Mason (8) conducted an  extensive study
on the  toxicity of chlorinated municipal wastewaters entering San  Francisco
Bay and  surrounding areas.  They observed a significant  increase  in toxicity
following chlorination.   Chlorine toxicity was still significant in aged (up
to 3 days) chlorinated wastewater,  in which TRC concentrations were  as high
as 25 percent of the initial level.    Rainbow  trout was  the  most sensitive
of the  species tested, followed by the golden shiner and three-spined stickle-
back.  A calculated  chlorine residual  of 0.03  mg/1, based on dilution of
a measured concentration  of 2.0 mg/1,  reduced plankton photosynthesis by
more than 20 percent  of the value obtained with a dilution of effluent having
no chlorine residual.   Dechlorination with sodium bisulfite  also  eliminated
chlorine-related toxicity.   One of  the  conclusions  of the California study
was that  chlorination may be  the largest single  source of  toxicity  in San
Francisco Bay.
                                     14

-------
    Martens and Servizi (9)  and Servizi and Martens (10) observed mortality
of salmon in receiving streams at TRC  concentrations as low as 0.02 mg/1.
Determinations  of  the  effect of time on chlorine residuals  were  made  by
sample storage  and lagoon retention.    Lethal concentrations persisted in
undiluted  effluent for at  least  50 hours.  Twenty to one dilutions resulted
in the chlorine residual declining to a non-detectable concentration after 12
hours.  Studies with live cages at points downstream  from  the effluent de-
monstrated acutely lethal conditions that did not persist during periods when
the chlorinator was inoperable.

    An ongoing project with the City of Wyoming,  Michigan  sponsored by
the U.S.  Environmental  Protection Agency, has  studied the chronic effects
of various disinfection techniques on the fathead  minnow. While the results
are incomplete and statistically untested, it appears that the toxicily of this
chlorinated effluent  is similar to that described above.   This  siudy  was
performed at the Grandville Sewage. Treatment Plant and was the first phase
of this project.

    As indicated  previously  many wastewater  treatment plants are required
to maintain a  residual chlorine  concentration of 0. 5 to 2. 0 mg/1. Most oper-
ators use  the orthotolidine  method which has been irequently shown to be
inaccurate resulting in much  higher concentrations than necessary for ad-
equate disinfection.  This compounds  the  toxicity problems  in the  receiving
waters. Total residual chlorine concentrations in  20 Illinois effluents ranged
from 0.98 to  5.17 mg/1 (11).   A similiar study at 22 plants in southern
Wisconsin resulted in observed concentrations of TRC between 0. ] 8 to 10.  3
mg/1 (12). Both studies demonstrated that the orthotolidine methods provided
the poorest results when compared with other methods such as the ampero-
metric titration technique.  Other studies (9,10) reached the same conclusion
that the commonly used orthotolidine method is inadequate to determine TRC
in wastewaters or receiving streams.

2.  Effects of dechlorinated  wastewater treatment plant  effluent.

    Several of the cited studies also evaluated the effect of various dechlor-
inationtechniques on the  toxicity characteristic of chlorinated wastes. Under
 laboratory bioassay  conditions dechlorination with sodium thiosulfate at sev-
eral Michigan plants resulted  in no acute mortality after 4 days in undiluted
effluent (3).   Chronic and  acute toxicity  tests by  Arthur et  al.  (5) usin:
sulfur dioxide for  dechlorination indicated that the  toxicity  was greatly re-
duced or  eliminated.  In the latter study  the  highest effluent  concentration
tested in  the  chronic studies was  20 percent; 100 percent  effluent was the
highest   concentration  jji  the  acute  studies.  Preliminary  results at the
Grandville, Michigan, plant have not been  statistically analyzed  but there
may have  been  slight chronic  effects at effluent  concentrations  of 100 and
50 percent dechlorinated waste. No effect was indicated at 25 percent. During
this study there also may have been adverse effects  in the undiluted,  un-
treated waste.
                                    15

-------
The Canadian studies (9,13) observed no acute salmon mortality in undiluted
effluent after dechlorination  by storage in a lagoon.   They also stated that
several California cities will  soon be  dechlorinating with  sulfur dioxide.
The toxicity  studies in California (6,7,8) observed that acute mortality in
undiluted  effluent was totally eliminated by dechlorination with sodium bi-
sulfite.

3. Effects of alternative disinfection of wastewater treatment plant effluent.

    a.  Ozone

   There is  a lack of toxicity data, for ozonated effluent at this time.  No
measurable  toxicity to aquatic life was  found in chronic tests by  Arthur
et al. (5)  using a 20% concentration of waste  disinfected with ozone.   Un-
realistic ally  high concentrations of ozone, relative to that needed for dis-
infection,  were necessary  to maintain concentrations of  0.2 to  0.3  mg/1
in a testing system where acute mortality occurred.   Typically, ozone dis-
sipated  rapidly between the  contact chamber  and the test chambers.  Pre-
liminary  results of comparable studies at the Grandville, Michigan waste
treatment pi mt indicate  that, the ozonated effluent had  no signi/icant effect
on fathead m nnow  reproduction, growth, or survival.

   During a  6-week pilot plant study by Nebel e_t al. (13) there was no mor-
tality of bass, perch., minnows,  and goldfish  exposed to undiluted ozonated
effluent at the Fort Southworth treatment  plant in Louisville.   These same
species did  not survive in the non-disinfected secondary effluent.   Spawning
in the undiluted,  ozonated  effluent  at Grandville was apparently  increased
over that  in the raw effluent..

   b.  Bromine chloride

   The only  significant data on the toxicity of brominated wastewater effluent
are preliminary  data from  the Grandville  project.  The acut<  toxicity of
this  effluent  is similar to that for chlorine but the  toxicity of :his effluent
declines at a. much greater  rate than that  for chlorine. The i ame  is  true
for-the chronic test. A 25 percent effluent concentration (0.018 n ij/1 bromine
residual)  had no chronic effect on reproduction  of the fathead min ow,  where-
as a 20 percent effluent concentration of chlorinated waste (0.10 ! mg/1 chlo-
rine residual) killed all the test fish.

   The principal characteristic of brominated effluent is  thai initially it
is: as toxic as chlorinated  effluent but its  toxicity becomes negligible  in  a
matter  of minutes whereas residual chlorine  toxicity may persist for many
hours.
                                  16

-------
MARINE

1.  Effects of chlorinated wastewater treatment plant effluent-

    Although limited information does exist on the effects of chlorine residuals
on marine  and estuarine life, few data are available on the effects  of the
wide spectrum of chlorinated hydrocarbons which are introduced into marine
ecosystems by discharge of chlorinated municipal treatment plant effluents.
Studies to  identify these compounds, their rates of formation and potential
impact on marine  communities have only recently been initiated.

    The results of a study by  Holland eit al  (14) indicate that  0.25 mg/1
chlorine was lethal to Chinook  salmon.    AT an exposure  time of 23 days,
the maximum non-lethal concentration of  residual chlorine for pink salmon
and coho salmon in sea water was 0,05  mg/1.  According to  the authors,
 no chlorimines were formed in sea water containing 0. 05 to 0. 5mg/l chlorine
and 3 mg/1  ammonia.  Alderson (15) found that the-48 and 96 hr TLm for
plaice larvae was 0.032  and 0.026 mg/1 free chlorine respectively.  After
96 hours exposure to  0.03 mg/1 chlorine,  the  feeding rate  of surviving
larvae gradually decreased by 50 percent.   Eggs were not affected by ex-
posure to 0.075 and  0.04 mg/1  chlorine  solution for 8 days indicating that
the protection  of the egg membrane allows normal development  over rela-
tively long periods even  at  chlorine concentrations which  would be repidly
lethal to hatched larvae.  The  72 hr and 192 hr  TLm for the  eggs was 0. 7
and 0.12 mg/1  respectively.

    Muchmore  and Epel (16) found that the fertilization success of  gametes
of the sea urchin Strongylocentrotus  purpuratus exposed to a 10 percent un-
chlorinated sewage-seawater mixture was reduced by  20 percent.  Chlorin-
ated sewage  further  reduces fertilization success in  concentrations as low
as 0. 05 mg/1 available chlorine.  These results indicate that the use of chlo-
rine disinfection could contribute to reproductive failure in external ferti-
lization of marine invertebrates in the vicinity of sewage outfalls.

    Galtsoff (17) observed  that the pumping activity of oysters exposed  to
0.01 to 0.05 mg/1 chlorine was  reduced.   Effective  pumping  could not be
maintained at a concentration of  1.0 mg/1.

    Tsai (18,19)   observed decreases  in the  abundance and  occurance  of
brackish water species including the common sucker,  Catastomus commer-
sonii,  the minnows,  Notropis cornutus, N. analostanus and N. prooni, and
the catadromous eel,  AnguillaTbstrata,  in certain areas  ofTKe  Upper and
Little  Patuxent Rivers receiving chlorinated sewage treatment effluents.
                                 17

-------
    Additional evidence for the effects of chlorine on marine environments
may be found from studies of the effects  of  chlorination of sea water on the
survival  of fouling organisms and on phytoplankton production.  Waugh (19)
observed  no significant difference in the  mortality of oyster larvae,  Ostrea
edulis,  exposed to 5 mg/1 chlorine  for  3 minutes at ambient temperature
compared to control mortality.  Exposure of larvae to thermal stress (10
C above ambient)  and 10  mg/1  chlorine for 6 to 48 minutes  also  had no
significant effect on  survival, 46 and 64 hours after treatment.   Barnacle
nauplii, Elminius modestus showed  more acute  sensitivity to chlorine.  Re-
sidual chlorine concentrations in excess of 0. 5 mg/1 caused heavy mortality
and reduced growth for survivors.

    McLean (21) simulated the conditions encountered by marine organisms
passing through  a power  plant  on the Patuxent River,  Maryland.  Intake
chlorination to 2. 5 mg/1 residual, entrainment  for approximately 3 minutes
and sustained  exposure  to elevated temperatures  for up to 3 hours  were
used as experimental parameters.    While  barnacle larvae, Balanus sp.
and copepods,  Acariatonai, were not affected by  a 3 hour temperature stress
of 5.5 and 11 C  above ambient; exposure to  2.5 mg/1 residual chlorine for
5 minutes  at ambient temperatures  cauaed  respective mortality rates of 80
and 90 percent,  3 hours after exposure.  Grass shrimp, Palaemontes pugio,
and the amphipod, Melita nitiday showed  a delayed death response after ex-
posure to  2.5 mg/1  residual chlorine for 5 minutes.  Nearly 100 percent
mortality was observed for  both species  96 hours after exposure to the
chlorine residual.

    Carpenter et al.  (22)  investigated the effects of chlorination on phyto-
plankton producHvTEy. An  83 percent decrease was observed  in the produc-
tivity of  phytoplankton passed through the cooling systems of  a nuclear gen-
erating plant  on  Long Island Sound which  received 1.2 mg/1  chlorine  at
the intake.  Essentially no decrease in productivity was observed when phy-
toplankton passed through the cooling system without addition of  chlorine.
Hirayama  and Hirano (23) found that Skeletonema costatum was killed  when
subjected to 1. 5 to 2.3 mg/1 chlorine for 5 to 10 minutes.

    Gentile et al.  (24, 25) National Marine Water Quality Laboratory,  West
Kingston,.  REoHe Island,  observed a 55 percent decrease in the ATP content
of marine phytoplankton exposed to 0. 32 mg/1 chlorine residual for two min-
utes and 77 percent decrease after  4.5 mimttes of  exposure to chlorine con-
centrations below 0. 01 mg/1.  A 50 percent depression, in the growth rates
of 10 species of marine phytoplankton exposed to chlorine concentrations rang-
ing from 0. 075 to 0. 25 mg/1 for  24 hours was also measured.
                                     18

-------
2.  Effects of dechlorinated wastewater treatment plant effluent.

    No information is  available on  the effects of dechlorinated effluents on
marine and estuarine  organisms.   Extrapolation of freshwater data to mar-
ine ecosystems would  indicate, however, that the dechlorination of effluents
would reduce chlorine toxicity significantly.

3.  Effects of alternative disinfection of wastewater treatment plant effluent.

    Research on the effects of  alternative disinfectants such as ozone is
only in preliminary stages relative  to marine ecosystems.  The agents re-
sulting from ozonation and  UV irradiation have been neither identified nor
analyzed for ecological impact.
RECOMMENDED CRITERIA

1.  Freshwater.

    Several reviewers of chlorine toxicity have recommended numerical cri-
teria for continuous concentrations  of TRC  that would not  adversely effect
aquatic populations.   Basch and Truchan (26) recommended maximum con-
centrations of 0.02 and 0.005 mg/1 for warmwater and coldwater fish, re-
spectively.  EIFAC (27) has suggested  criteria dependent upon pH and temp-
erature with an acceptable upper limit of 0. 004 mg HOC1/1 (TRC  from 0. 004
mg/1 at  a  pH  of  6.0  and 5   C to  0.121 mg/1 at a pH of 9.0  and  25 C).
A third review  by Brungs (28) has  recommended  a criterion of 0. 01  mg/1
for warmwater  fish and 0.002 mg/1 for coldwater species and the most sen-
sitive fish  food organisms.

    These criteria may  eventually be influenced by ongoing  studies that are
investigating chlorinated residues in fish tissues resulting from chlorination
of waste effluents.

    No criteria  can be considered as yet for ozone and bromine chloride al-
though available data  indicated that the toxicity of  effluents  disinfected with
these materials is less than with chlorinated effluent.

    Similarly, no  criteria for various dechlorinated chemicals (e.g.,  sodiuni
bisulfide,  sodium  thiosulfate,  and  sulfur dioxide) can be proposed  at this
time.  No adverse acute effects of dechlorination have been observed.  Pre-
liminary  data indicate  possible slight chronic effects but  only  in  100 and
50 percent raw dechlorinated effluent.
                                    19

-------
2,  Marine.

    Although chlorination is used to eliminate undesirable levels of organisms
that would  degrade water  uses,  it is evident that the effects of chlorine on
desirable marine and estuarine species is a serious hazard. No information
is available on the effects of toxic chlorinated products on marine life.  It
appears,  however,  that  free  residual  chlorine in sea water  in  excess of
0, 01 mg/1 can be hazardous to marine life.  Additional study of many organism
types  under a wide variety of environmental conditions is needed to establish
a recommended value for chlorine.
                               CONCLUSIONS
    1.  Trout,  salmon,  and some fish-food organisms are more sensitive
than warmwater fish, snails, and crayfish.

     2.  Chronic toxicity  effects of TRC on growth and reproduction occur
at lower concentrations than those causing mortality.

     3.  Dechlorination with sadism! biosulfite, sodium thiolsulfate, and sulfur
dioxide, or certain other compounds, greatly reduces or eliminates  toxicity
caused by TRC.

     4.  Brominated effluent may be as  toxic as chlorinated  effluent but its
toxicity  is reduced  to no-effect concentrations in a much shorter period of
time than chlorinated effluent.

     5.  No acute adverse effects of ozone were observed  in as high as  100
percent effluent.

     6,.  Non-disinfected secondary domestic  effluents  have only slight toxi-
city tofreshwater organisms at concentrations as high as 100 percent effluent.

     7.  Chronic toxicity  effects of TRC on marine organisms occur at lower
concentrations than those causing mortality.

     8.  Sublethai concentrations of chlorine can reduce productivity of marine
phyt oplank ton.

     9.  Larval stages of marine forms appear to be more sensitive to chlorine
than cither the egg or .adult stages.
                                  20

-------
        SECTION VI - DISINFECTION PROCESS ALTERNATIVES

Program Background

    The Municipal Pollution Control Division and the Ecological Processes
and Effects  Division have  supported an active program in  developing new
disinfectants and techniques for application to waste treatment plants efflu-
ents and combined sewer overflows. Many of the completed project;; have
provided the basis  for  the  present research program  and nave greatly
contributed  to the present state of the art. A list of completed and on-going
projects is  presented  in  the  Appendix to give the reader  an overview of
the activity  in this area.

    An important and major part of the program in this area is an on-going
grant with the  city of Wyoming,  Michigan.  The  project was designed to
test the toxicity of  residual  chlorine  to aquatic  life;  investigate  alter-
native methods  for  disinfection of wastewater;   and  test the  toxicity of
those methods  to aquatic  life. The alternative processes being studied  are
disinfection with ozone and bromine chloride,  and  the neutralization of  re-
sidual chlorine  in chlorinated effluent  with  sulfur  dioxide. The study is
a cooperative effort between  the Grand Valley State Colleges,  Allendale,
Michigan, and the cities of Wyoming  and Grandville,  Michigan. Funding
for the bromine chloride  disinfection  study has been  totally provided by
the Dow Chemical  Company and Ethyl Corporation.  The Grace Chemical
Company  has provided ozonation  equipment and information dealing with
the application of ozone to wastewater.

    The following is a discussion on the  alternative  processes that have been
developed and their general standing in regard to immediate and future  ap-
plication.
OPERATIONAL PROCESSES

Liquified Chlorine Gas (Molecular Chlorine)

General

    Liquified chlorine gas (subsequently referred to as chlorine) is soluble
in water  (0.0608 Ibs/gal.  at  20°C).  For practical  purposes the storage
life  of  chlorine is essentially unlimited.  It assumes two forms in waste-
water that account for most of its disinfecting activity:

    1.  HOC1 (hypochlorous acid)  which is extremely effective in  killing
        both, bacteria and viruses.

    2.  Monochloramine,  the  dominant form  in wastewater, a persistent
        but relatively slow acting disinfectant.


                                   21

-------
The reason for the dominance of monochloramine is that practically all waste-
water exMrtains ammonia and most of the chfo^eine applied is very rapidly con-
verted5 to monochloramine at normal wastewateir'pH of slightly above 7. 0. Other
chlorinated compounds  such as organic chlgramines are formed but these are
of little germicidal importance in the disinfecticSn of wastewater.

Status

    Chlorine is currently the predominant wa'atewater  disinfectant and  it  is
essentially the exclusive  disinfectant if one^uicludes  its counterpart,   sodium
hypochlorite,  which will be covered subsequently1' in a separate  section.  A mini-
mum chlorine  contact time  with a  specifiecU?phlorine residual  is  included  in
some state standards.   Others rest on. EPA^regulations or specify that certain
bacteriological standards be met.

Equipment and Chemical Suppliers

    There is a wide  variety  of  sources of. equipment for adequately  applying
and controlling the use of chlorine for disinfection of  wastewater.   The  field
is exteemely  competitive.   There was  some^concern for availability  of ade-
quate siajpplies of both chlorine and snipping*c.pntainers early in 1974  (1).   In
ttoe EPA Disinfection Policy Ta-sk Force meej±r?gfon July 9, 1974, it was reported
that tkere was no shortage of either container^s^or chlorine for water and waste-
waiter disinfection.

Safety

    Liquid chlorine is a hazardous chemical  and chlorine gas  is  toxic  and can
cause d^eath by suffocation (2). It irritates the^respiratory tract mucous surfaces
and the  skin.  Direct contact  with liquid^Jchlorine  can cause serious burns.
safety equipment (gas masks) is required forss|rp.ergency protection in all poten-
tially dangerous  areas.  Safety precautions iriu^ibe excercised  in all shipment,
storage,  and use  areas.  The  liquid vapq^zjrs at  atmospheric  pressure and
ambient temperatures.  The gas is  2-1/2 times^as heavy as air and will persist
in low areas.

Reliability

    CMowine is  generally a  reliable diissara^ctant.   There is  clear-cut evi  -
cLertee tfet  chlorination of waystewater dtestrojjPBii  enteric pathogenic bacteria.
In a study on the  occurrence of Salmonellae in;the receiving stream after waste-
water  chlorination, Salmonellae were not detected-in either chlorinated effluents
or the receiving stream during a 7-month period when effluents were chlorina-
ted. After chlorination was discontinued, Salm'bttellae were isolated.  When chlo-
rination was resumed,  however,  they were^rnpt detected in samples collected
dmring a 4-week period  (3).
                                     22

-------
    The value of  the coliform test is indicated by the  fact that "...  epidemics
of hepatitis originating in chlorinated water supplies judged satisfactory by the
coliform test have not been reported except where  obvious deficiencies in chlori-
nation practice were shown or suspected1 (4). Apparently, the coliform test pro-
vides a  good  measure  of  protection against the one virus  disease  that has fre-
quently  been the cause of waterborne  epidemics.  Basically,  its  effective use
for  disinfection of wastewater requires an understanding of the disinfecting effi-
ciency of  hypochlorous acid  (HOC1) hypochlorite ion  (OC1) and   chloramines.
(4).  The primary disinfectant form of chlorine  in current wastewater treatment
practice is monochloramine and other forms of combined  chlorine. Disinfection
of secondary effluents can reliably meet stringent bacteriological standards.
Only limited  information  is available on  the virucidal effect of monochloramine
and what is available indicates that it  is a slow acting virucide (5).  To ensure
adequate protection from viruses,  long-term  exposure to  monochloramine is
required,  whereas chlorination  to breakpoint (HOC1 residual) will rapidly de-
stroy both viruses and bacteria (6).

Research

    The present research program is implementing a comprehensive project to
improve chlorine contactor  design and mixing under  EPA Grant No.  803459,
"Reduction of Unit Toxicity Emission Rates from Wastewater Treatment Plants
by Optimization of the  Chlorination Process."  This will  include preparation of
a design manual for chlorine contact systems. An improved understanding of the
effect of combined chlorine  on  viruses is being sought under EPA  Grant No.
800370, "A Comparative  Study of the Inactivation of Viruses in Wastewater by
Chlorine and Chlorine  Compounds."  A search is underway for "New Microbial
Indicators of Disinfection Efficiency," jointly funded by EPA and the Army
under an Interagency Agreement  EPA-IAG-D4-D432 (formerly EPA Grant No.
R-800912).

    Improved technology  for application of chlorine to effluents from lagoons,
oxidation  ponds,  and related treatment  processes will be investigated under a
contract with Utah State  University to "Determine Chlorination  Requirements
to Satisfactorily  Disinfect Lagoon Effluent to Meet Secondary Treatment Stan-
dards." Award of contract is pending. There is a need for improved instrumenta-
tion for monitoring residual chlorine and automation for better control of dosage
response in relation to residual chlorine.

Costs

    With the exception of chlorine much  of the cost information presented must be
considered tentative at this time.  For example  there  have been no full scale
plant demonstrations to support  cost analysis  for wastewater disinfection with
ozone, bromine chloride  and ultraviolet light  or dechlorination  with  carbon.
The dosage  assumed  for chemical disinfectants is  8 mg/1 to achieve disin-
fection.  Costs of disinfection with chlorine are presented in Table I (7).
                                    23

-------
                                Table I

                        Chlorine Disinfection Cost

Plant Size,  MGD                  1                 10              100

Capital Cost,  $                 60, 000           190,000          840,000

Disinfection Cost,  jzr/KGal       3.49              1.42              0.70



Sodium Hypochlorite (NaOCl)

General

    The disinfecting potency of 1. 0 mg/.l of chlorine derived from sodium hypo-
chlorite is just as effective as an equivalent  amount of chlorine as hypochlorite
ion (OCirderived  from liquified chlorine gas.  Either  chlorine gas or sodium
hypochlorite in aqueous solution at concentration's used for wastewater  disinfec-
tion,  assume  the same form and  are equally available  to react with  ammonia
or other wastewater components (4).   Sodium hypochlorite  is only available as
an  aqueous concentrate.  The optimum concentration of  sodium hypochlorite in
terms of maximum concentration and stability is 15 percent (8).  Sodium hypo-
cfalorite  solutions must be protected from freezing.  The concentrated solution
is highly corrosive to most common metals and  wood.  Sodium hypochlorite
solutions lose oxidizing power during storage. A solution of sodium hypochlorite
that contains  15 percent  of available chlorine by  volume when stored at 75°F
will lose half of its original activity in  100 days  (9).  Storage above 85°F is
not recommended.  Lower  concentrations will not deteriorate so rapidly,  but
increased  storage capacity is required.

Status

    Increasingly,  certain  wastewater  treatment plants are turning to the use
of sodium  hypochlorite because it is safer than liquified chlorine gas (8).  Two
examples  suffice  to illustrate  this point, namely,  the cities of New  York and
Chicago.  A limited number of  other plants are making  the change for  the same
reason - to avoid  storage  of liquified  chlorine  gas  in  plants with close prox-
imity to heavily populated areas.

Equipment and Chemical  Supplies

    With the exception of  the feeder, storage, and some piping, a hypochlorina-
tion syste.m is very  similar to that for a  system using liquid  chlorine  (8).
Equipment is available  for on-site  generation  of sodium  hypochlorite or the
chemical  can be purchased and  stored  in tanks; therefore no major supply
problems  are anticipated.
                                    24

-------
Availability of sodium hypochlorite should be'essentially the same as for chlo-
rine.  Chlorine gas is produced by electrolysis of brine with sodium hydroxide
as a by-product. Sodium hypochlorite is produced by recombining the  chlorine
with sodium hydroxide.

Safety

    The primary reason for using sodium hypochlorite instead of liquified chlo-
rine gas is because it is safer.  Nevertheless,  it  should be clearly understood
that sodium  hypochlorite is hazardous and proper safety precautions should
be employed.   However,  a  number  of large users,  including the cities of New
York  and Chicago,  are  apparently willing to pay the premium for the greater
safety aspects of this product in comparison to liquid chlorine" (8).

Reliability

    The active forms of chlorine derived from sodium hypochlorite and liquified
chlorine gas are the same when applied to wastewater.  Accordingly, the advan-
tages and disadvantages with regard to disinfection reliability are essentially
the same for sodium hypochlorite and liquified chlorine gas.

Research

    Needs essentially the same  as for liquid chlorine.

Costs

    When considering  the entire system of piping,  storage  tanks,  diffusers and
instrumentation and feeders, there is usually only a small percentage «f differ-
ence in capital  cost of liquid  chlorine and  sodium  hypochlorite  systems  (9).
Current costs of sodium  hypochlorite indicate that available chlorine as  sodium
hypochlorite costs approximately 2.5 to 10 times more than liquified chlorine
gas depending on the volume treated  (10).  For comparison, apply these  factors
to the disinfection cost in Table  L
Dechlorination with Sulfur Dioxide (SO?)

General

    Since chlorination of wastewater causes chlorine residuals that can be toxic
to aquatic life,  dechlorination may have to  be practiced in some situations.

    Sulfur dioxide is the best direct reacting chemical agent available for wide
scale use in dechlorinating wastewater.   It  is available  commercially as the
liquified gas and is much more soluble than chlorine in water (1.0 Ib/galat 60°F).
Upon dissolving  sulfur dioxide in water  a weak  solution cf sulfurous acid is
                                    25

-------
formed.  The dechlorination reaction of sulfur dioxide with both free and com-
bined chlorine residuals is nearly instantaneous (11).  Contact chambers are not
necessary but rapid and complete mixing at the point of addition is important.
The reaction weight ratio of sulfur dioxide to chlorine is 0. 9:1. 0 which converts
chlorine to  the chloride ion.  The sulfur dioxide dosage needed is  that sufficient
to neutralize  the residual  chlorine.   Sulfur dioxide  appears to be  effective
in preventing toxic stress to receiving water biota. There is no reason to expect
that its use will exert any effep-t on chlorinated organic compounds resulting
from disinfection with chlorine.   However research is required to determine
if this assumption is correct.

Status

    Sulfur dioxide  has long been used  to neutralize chlorine in treatment of
idrinking  water,  but  its  use  for  .dechlorination  of wastewater  is just getting
underway.   Information obtained in October 1974 on four wa.stewater  treatment
plants with  average daily  flows -ranging from 4.0 mgd to  160 mgd indicaied
no serious  problems  in  dechlorinating  with  sulfur -dioxide.   Of these plants,
the Sacramento City plant (flow 50 mgd) had been using sulfur dioxide dechlori-
nation for 9 months (12).

Equipment  and Chemical Supplies

    -Equipment for feeding sulfur dioxide is very similar to thai used for chlorine
and no  serious difficulties in the supply situation for equipment or  sulfur .dioxide
are ^anticipated.

Safety

    Sulfur dioxide is a hazardous highly corrosive-.and  extremely irritating gas
that causes skin  and eye  burns and damages mucous surfaces.   It is self-
warning.    It is  less prone to -rapid volitalization than chlorine (vapor pressure
of sulfur dioxide at 70 F is 35 psi while the corresponding value for chlorine is
90 psi).  Handling precautions are similar to chlorine  but the lower pressures
of sulfur  dioxide are less prone to cause leakage problems.

Reliability

     Sulfur dioxide  is  a reliable chemical .agent for removing residual chlorine
from water and  wastewater.   As sulfur dioxide  is a reducing agent,  careless
operation can lead to reduced dissolved oxygen content  of effluents.   As a
result, some states are  requiring reaeration  to increase  the dissolved oxygen
 content of the effluent when sulfur dioxide is used to dechlorinate.
                                     26

-------
Research

   An important area where research is needed is in  the study of aftergrowth
following  dechlorination. Complete removal of bactericidal effects may result
in increased  aftergrowth.   This problem is  likewise anticipated with disin-
fectants  such as ozone and ultraviolet light which leave no lasting residual.

Costs

   Costs for both dechlorination with sulfur dioxide and restoration of dissolved
oxygen ccntent are presented in Tables  II and III.   To obtain the total cost of
disinfection,  the chlorination cost in Table I must be added to the dechlorination
and the o :ygen restoration cost in Tables  II and III (7).
                                    Table II

                      Dechlorination with Sulfur Dioxide Cost
Plant Size,  MOD              1                10                100

Capital Cost,  $             11,000           29,000            94,000

Disinfection Cost, /«/K Gal   0.88             0.33              0.19



                                Table III

     Cost for Post Aeration Following Sulfur Dioxide Dechlorination

Plant Size,  MGD              1                10                100

Capital Cost, $              49, 000          140, 000           650, 000

Disinfection Cost,  tf/KGal   3.29             0.64              0.30
                                    27

-------
ALTERNATIVE PROCESSES

Dechlorination with Activated Carbon

General

    Chlorinated effluent can be "dechlorinated by treating the effluent with
activated carbon.  This technique is a physical process in which chlorinated
amines,  free chlorine and chlorinated organics are  removed by sorption
cm the carbon. This polishing step not only alleviates the problem of toxicity
associated with chlorine but it also removes residual refractory organics
and some of the potentially-toxic chlorinated organics.

Status

    Activated  carbon  is used as a  tertiary treatment stage for  reducing
the chemical oxygen demand (COD) of wastewater at  several waste treatment
facilities.  This technology is  applicable for the design  and operation of car-
bon systems for dechlorination (13).   The practice of dechlorination with
activated carbon  is used  as  a supplementary treatment  for  water supply
by the brewery and  soft drink industries  (14). Its use  in  dechlorinating
wastewater treatment has been limited to a pilot plant evaluation at Owosso,
Michigan (15).  The results  from the Owosso facility  proved the feasibility
of this process to adequately remove the free and  combined chlorine from
the effluent.  However a full scale  demonstration  is  required to establish
the cost  of dechlorinating with carbon.  This process is the most  costly
of the many alternatives in regard to both capital and operating costs.

Equipment and Chemical Suppliers

    As mentioned above, activated  carbon is used  for  COD reductions as a
tertiary treatment stage.  The equipment and material (carbon) is available
for ready implementation. The mode of operation in which the effluent flows
thru a static bed of carbon reduces the operating difficulties normally asso-
ciated in dechlorination with chemicals, such as sulfur dioxide.  Biological
growth on carbon may  reduce the  dissolved oxygen level of the effluent and
require  post aeration treatment before discharge.

Safety

    The  operation of a carbon column requires no special precautions. How-
ever when it becomes necessary to perform internal maintenance or inspect
the inside of the carbon .column, special safety precautions must be taken
to avoid CO and CO2 inhalation or an atmosphere devoid of oxygen.
                                     28

-------
Reliability

    The Owosso,  Michigan pilot plant  study  for  dechlorinating wastewater
with carbon showed that the  carbon consistently removed the free and com-
bined chlorine. Long term tests are still required to determine the influence
of organic loadings on the efficiency of the chlorine removals and to deter-
mine if aftergrowth occurs on the carbon beds.

Research

    Dechlorination  with carbon is a medium priority process in the program
to develop alternatives  to chlorination.  Cost estimates  have shown this
process to be the  most  costly alternative.   More significantly,  the  cost
estimates assume  that the  carbon will perform for several  years before
replacement,  thereby eliminating  carbon regeneration facilities.  This as-
sumption needs verification  before such a system can be placed into opera-
tion. Since the costs for dechlorination with carbon are significantly higher
than other alternative processes,  carbon dechlorination research is classi-
fied at a medium priority level.

Costs

    The cost of dechlorinating with carbon is'shown  in Table IV (7). The cost
for chlorination is  included in the capital and disinfection cost for dechlori-
nation with carbon.

                                Table IV

                         Dechlorination with Carbon

Plant Size,  MGD               1                10               100

Capital Cost,  $             640, 000         2, 800,  000        8, 400, 000

Disinfection Cost,  c/K Gal   19.00              8.60              3.28
Ozone

General
    Because of its high oxidation potential,  ozone  has received the most
attention  as a disinfectant alternative  to chlorine.   Ozone is a chemical
disinfectant that may derive its germicidal properties from the formation of
nascent oxygen in the breakdown of ozone.    In addition to  disinfection,
ozone reduces  the color and  odor  of  wastewater.   Although ozone is  13
times more soluble in water  than oxygen,  it is difficult to dissolve more
than a few mg/1 of ozone  because the ozone gas concentration during gen-
eration is between 1 and 3 weight %. Ozone decomposes in water to formh
molecular oxygen.

                                     29

-------
.Status

    Ozone hasbeenused for sixty years to treat water supplies in Europe and
Canada.  Its use in wastewater applications  has  been limited to pilot plant
studies  to establish feasibility,  reliability,  process  limitations and cost
information.

    Although there are no full scale plants using  ozone to  disinfect waste-
waters  at   this time,  there are  five locations  (Springfield,  Missouri;
Meander Lake,  Ohio;     Estes  Park,  Colorado;    Indiantown,  Florida;
Woodlands,   Texas) that  have specified  ozone for the disinfection stage.
Several of these plants  are  now under construction and all five locations;
have included filtration as a pretreatment stage tor ozunation.

Equipment

    Ozone generation consumes more  energy than other  disinfectants.  It
is produced  on-site by  the application of an electrical discharge across
oxygen or air.  This phase is being gradually improved by the many manu-
facturers of ozone equipment. At present, approximately 6 kilowatt hours
of power are required to generate one pound  of ozone from pure oxygen;
'•whereas 12 kilowatt hours are required to generate one pound of ozone from
«ir. For comparison,  chlorine uses  1. 3 kilowatt hours  of  electricity  to
produce one pound of chlorine.

Safety

    Ozone is a toxic gas that  requires special design considerations to pre-
vent its escape into an operating area.  Vent gases  must be treated to convert
the ozone to oxygen before  releasing the gas  into  the  atmosphere.  The
maximum allowable concentration for an eight hour day exposure of ozone
to huma.is is 0.1 ppm.  However,  the odor  of ozone is  readily detected.
The olfactory  threshold  odor concentration for  the  general population  is
0.02 to 0.05 ppm,  which enables operating personnel to  take  corrective
action on sensing ozone (17).

Reliability

    Recent pilot plant studies at Wyoming, Michigan,  and  Chicago,  Illinois
(18) have shown that it is difficult to disinfect  secondary effluents with ozone
and consistently meet nominal bacteriological standards. Tertiary treatment
is required. Filtration has been shown  to be an effective treatment  stage
to enhance the disinfection efficiency of ozone.

Research

    The EPA research program investigating alternatives in the disinfection
of waslew'c'.ter  has  assigned  ozone a  high priority.  Work is underway  to
optimize ozone utilization by improving various contacting systems.   Re-
                                    30

-------
search plans also call for demonstrating ozone at two of the five previous-
ly listed  sites. One site will evaluate ozone produced from pure oxygen and
the other site will evaluate ozone produced from air to obtain comparative
cost data for ozone application as a disinfectant.

    Research  is  still required to find a parameter for controlling  ozone
dosage.  Present technology utilizes a constant ozone dosage which results
in excessive ozone consumption or inadequate disinfection.

    Residual oxidation products need to be investigated to determine if toxic
compounds are formed when the reaction of ozone with organics does not pro-
ceed to completion (CC>2and HJD).

Costs

    The costs for disinfecting wastewater with ozone generated from air and
from oxygen are shown in Table V.

                               Table V

                       Ozone Disinfection Cost

                      Ozone Generated from Air

Plant Size,  MGD            1              10               100

Capital Cost,  $          190, 000       1, 070, 000         6, 880, 000

Disinfection Cost 
-------
effect is a function of wave length and  is greatest between 2500 and 2600
aagstroms (A).  With the advent of low-pressure mercury lamps approxi-
mately 85% of fie lamp's energy is emitted at 2537 A (19).

    For UV to l>e an effective germicide,  the energy dosage must reach the
organism.  Some of the factors that may affect the penetration of UV energy
into water  are  urbidity,  color and organic compounds.

Status

    UV is used as a  disinfectant  for  dimineralized water systems. It is
used for disinfecting potable water systems in overseas hotels,  cruise ships
restaurants and vacation camps.   There are many industrial and product
w-ater applications that use UV, such as breweries, pharmaceutical man-
ufacturers, and fish hatcheries (20).

    UV has net been studied extensively  as  a  disinfectant for wastewater;
however,  its feasibility  was demonstrated at 44, 9-&0 GPD at St. Michaels,
MD (21).   Its reliability was  highly dependant  upon effluent quality. Addi-
tional research  is  required to establish minimum pretreatment require-
ments to optimize  design  parameters,  such as UV   dosage,  hydraulics,
contact t me ard energy  requirements.

    There  is under  construction a  2 MGD treatment plant with UV disinfec-
tion at-a new community  development near Rochester, N. Y.. As with ozone,
the facility will  utilize  filtration as a  tertiary treatment stage prior to
UV disinfection. This system is scheduled to go  on stream  at minimum flows
during the  spring of 1975.    Chlorination facilities have  been included at
the site to serve as a backup disinfection process.

Equipment

    There  are numerous suppliers of UV equipment  which will ensure a
competitive market if UV surfaces as a viable alternative.  The equipment
manufacturers have made  significant product  improvements  in regard to
equipment, maintenance,  contact, and  dosage. The manufacturers incor-
porate a continuous UV  monitor to measure transmission,  which can serve
as a parameter to monitor the disinfection.

Safety

    The operation of a UV system  can  produce ozone and safety precau-
tions covered  under ozone may also be required  for UV systems.   The
newer designs of UV equipment have enclosed  chambers  to protect  opera-
tors .against irradiation exposure which  can  be harmful to the eyes and
skin.
                                    32

-------
Reliability

    The small plant study at St.  Michaels,  Md.   showed  that good quality
effluent could be disinfected with UV.   Poor quality effluent will require
tertiary treatment to provide adequate disinfection.  Additional research is
needed to provide process and cost optimization to ensure adequate disinfec-
tion with minimum  treatment stages.

Research

    The EPA research program has initiated a study of UV at Dallas, Texas
to evaluate some of the latest equipment with various pretreatment stages
and to determine the most  cost effective  design combination.  The facility
under construction  near Rochester,  N.Y. will be  considered as a potential
demonstration site  to establish costs for UV disinfection.

Costs

    The estimated cost  for disinfecting wastewater with UV is shown in
    Table VI.

                                   Table VI

                      Estimated  Disinfection Costs with UV
Plant Size,  MGD               1              10             100

Capital Cost,  $             71,000          360,000       1,780,000

Disinfection Cost,  $/KGal   4.19             2.70            2.27



Bromine Chloride

General

    Bromine chloride is a chemical disinfectant, and  is similar to chlorine
in its germicidal  qualities.    One of its  advantages is  that bromamines,
formed as  a reaction product of hypobromous acid  with ammonia,  are also
effective germicides.   In fact, bromamines are far superior to chlora-
mines in bactericidal and viricidal activity.  In  addition bromamines are
less stable  in water and break down to form bromide salts.22
                                  33

-------
Status

    Bromine chloride  is  the  newest  candidate  in search of an  alternate
disinfectant.  Its applicability as a disinfectant has progressed rapidly by
the research activity of its manufacturers.   The manufacturers have per-
formed bench scale feasibility studies on bromine chloride and moved rap-
idly into pilot plant evaluations,  by joint funding with EPA on the bioassay
and disinfection study at Wyoming, Michigan.    At the present time, there
are no bromine chloride facilities in operation nor are there any in the design
phase; however  the State of Maryland is actively searching  for a potential
site to demonstrate the effectiveness of bromine chloride as an alternate
to chlorine.

Equipment - Chemical Suppliers

    Existing chlorination facilities would require only minor modifications
to convert from chlorine to bromine chloride.

    There are three known manufacturers of bromine chloride. Each of the
three would actively promote bromine chloride for wastewater disinfection
if the product showed  promise of replacing chlorine at specific  locations.
Bromine chloride development as a disinfectant was initiated  by Dow Chem-
ical Co.  when  their marketing studies indicated that bromine would be a-
vailable for other uses as the quantity of leaded gasoline decreases.  Pre-
sently 55  to 60%  of  the  bromine goes toward  the production of  ethylene
dibromide  (EDB),  a lead  scavenger  in leaded gasoline.  Recent studies
indicate  that the  decay in EDB  demand amounts to 5% a year.  We  may
assume that BrCl  supplies are limited now and will be limited in the near
future.  According to the  manufacturer, "Requests for the  chemical will
be handled on an individual basis."

Safety

    Bromine chloride requires the same care in handling as chlorine.   As
such the same precautions  that are used in shipping,  handling,  and storing
chlorine are required for bromine chloride.

Reliability

    The pilot plant work at Wyoming,  Michigan,  has shown that bromine
chloride is an effective disinfectant requiring no pretreatment i'or an acti-
vated sludge effluent.  Bromine  chloride can  accomplish the same degree
of disinfection as chlorine with a lower final halogen residual, but the min-
imum level has not been established.
                                     34

-------
Research

    Additional research is  required to optimize bromine chloride contact
systems and to establish a minimum effective halogen residual. Thetoxicity
of brom'inated organic compounds is generally greater than the correspond-
ing chlorine compounds and additional studies will be required to determine
the health effect consequences. Since its chemical behavior is similar to
chlorine,  its development has progressed more rapidly than other alterna-
tives. To take advantage of the potential for lower halogen residuals, in-
struments need to be developed to ensure adequate monitoring of the efflu-
ent. Because of the potential commercial applicability of bromine chloride,
the manufacturers have made a major contribution to its accelerated de-
velopment.

Costs

    The cost of  disinfecting wastewater  with bromine-chloride  is shown in
Table VII.   A cost summary is shown in Table  VIII listing the disinfectants
with their capital and total disinfection costs.

                               Table VII

                     Bromine Chloride Disinfection Cost  (7)

Plant Size,  MGD               1             10             100

Capital Cost,  $              47, 000       129, 000          414, 000

Disinfection Cost, «4/K  Gal    4.52           3.04             2.65
OTHER POTENTIAL DISINFECTANTS

Chlorine Dioxide

    Chlorine dioxide (C1O2 ) is one of the newer halogen disinfectants that
have shown promise for use in water  and  wastewater treatment.  It  is a
powerful oxidizing agent and an excellent disinfectant.

    Chlorine dioxide is unstable and extremely corrosive.   In practice,  it
is usually  generated from  the  reaction between sodium chlorite  solution
and chlorine in contact  with  the water to assure that the  gas  remains in
solution  to avoid explosion hazard.  Sodium chlorite (NaClC^), from which
the gas is  usually generated) is also explosive and the hazards of handling
chlorine have already been listed. Proper handling minimizes these  hazards
but responsible personnel are required  where it is used.
                                    35

-------
    The lack of an adequate method for accurately determining low residual
concentrations of chlorine dioxide is a serious drawback.   Because it is
such a strong  oxidizing agent, more  C102   than chlorine may  be required
to disinfect wastewaier.

    Factors other than the cost of the chemicals used may govern the expense
of wastewater treatment. Here, -however,  only cost of materials is consid-
ered. The  cost  of NaC103and  CL^required  to produce one pound  of CIO is
about 13 times more than oae pound" of CL.
Lime at pH 11.0 or Higher

    It is unlikely  that lime would 3®e seriously considered for disinfection
only.  However,  lime has pronoimeed potential for icornbined treatment and
disinfection of wastewater.

   Results  from EPA  sponsored studies under Grant No.  16100 PAK,
"Lime Disinfection of Bacteria at Low Temperature," are indicative of the
effectiveness  of lime as a disinfectant. Even in the presence of relatively
high concentrations  of organic  matter and uncter the adverse conditions of
low temperature  sewage  can be disinfected  to a safe level by lime treat-
ment to pH 11. 5 or  12.0.  A variety of generic types of bacteria  can be
destroyed  during  lime treatment,  as evidenced by  the  large reductions
in total and fecal coliform content of both the effluent and the sludge. The
process of disinfection can be completed within a relatively short time peri-
od (30 minutes or  less),  even  at 1°  C.  Additional benefits  that  can be
realized from lime treatment are reductions in organic materials and phos-
phorus.   If the removal of organic chemicals and phosphorus is not neces-
sary,  the cost of disposing of the sludge resulting from lime treatment would
have to be considered as  part of the disinfection cost.

Bromine

    Bromine is a liquid at 'atmospheric pressure and is safer to handle than
chlorine.  It produces fumes which are very irritating and the liquid causes
severe burns. It is a good germicidal-agent and effective tests are available
for determining residualcorreentrations.   As with chlorine,  the amine form
is produced when Ammonia is present, and the ^breakpoint phenomenon has
been demonstrated. Bromine, hypobromous.acid (HOBr), and monobroma-
mine are considered nearly equal in bactericidal properties and essentially
equal to  free chlorine %t comparable pH.   Some of the advantages given
for using  bromine are:  (a)  it  is easier to  feed and  not as hazardous to
store as chlorine; and (b) the bactericidal efficiency of bromamines is much
greater  than  thai of chloramines. Data accumulated on an EPA sponsored
Grant No.   17060 DNU by  the  Illinois Water  Survey Laboratory indicate
that the  effectiveness of chlorine decreases with increasing pll, whereas
bromine is most effective at high pH. This indicates potential for use with
effluents  subjected  to phosphate  removal with  lime or ammonia stripping
where the  effluents have  high pH. Possible potential for combining bromine
and chlorine for  disinfection was  indicated.  Cost-wise liquid bromine costs
approximately 3. 5 times more than chlorine.
                                     36

-------
Iodine

    Commercial iodine is a nonmetallic  solid.  It is  usually  referred to
as "metallic"  iodine  and has the appearance of dark,  shiny,  thin pieces of
metal.  In this form it is corrosive and ordinary metal containers are unsuit-
able for shipment or  storage.   It is dense  and sublimes  slowly at room
temperatures.   The  hazards due-- to  toxic vapors  of  iodine  are  less than
the other halogens considered for disinfection of water or wastewater.  The
vapor pressure of iodine  at 25° C is only 0. 31 mm Hg.  The  corresponding
figures for bromine  and  chlorine are 215 and 5, 300 mm Hg respectively.
Iodine  is not considered  to  form iodamines under conditions prevailing in
wastewater and organic demand may be less of a problem than with chlorine
and bromine.  Plant treatment of large volumes of wastewater with iodine
would not  ordinarily  be  economically feasible because  it is significantly
more expensive than chlorine,  in  terms of  cost  per  unit  of germicidal
effectiveness.  Its primary potential may be for use in arctic fly-in outpost
settlements where it can be  shipped in light weight  cardboard  cartons.
The cost  of disinfecting  with  iodine is  roughly 18 times more  than  the
cost of an equivalent amount of  chlorine. While some reduction in  dosage
with iodine might  be  considered  because of probable increased presistence
of the germicidal  residual,  the  economics  are strongly against  the use of
iodine as a substitute for chlorine except under circumstances where cost
is a secondary consideration.
Ionizing Radiation

    Ionizing radiation has been studied extensively as a potential sterilizing
agent for  foods.   Its use as a disinfectant of wastewater effluents, either
alone or in combination  with another disinfectant,  has been  suggested in
the literature.  Its potential advantages  include:  (a)  greater penetrating
power than other  forms  of  radiation,  such  as ultraviolet light;  (b)   no
residual produced in the effluent stream; (c) capability of initiating oxidation
of organic molecules and refractory pollutants.

    The sources of high  energy radiation are  cobalt-60, cesium-137,  elec-
tron accelerators,  reactor  loops,  fuel elements,  and mbced fission pro-
ducts. Each must be analyzed in terms of cost, availability,  characteris-
tics,  and  installation requirements.  All  radiation devices require special
shielding  and handling facilities,  constant monitoring of radiation areas,
keeping of personnel exposure records, etc.  The electron accelerator  fa-
cility requires electric power for operation. Due to the dearth of information
relative to the practicality of any of these radiation  sources,  only rough
cost estimates have been made.  A recent study investigating the combined
bactericidal effect of cobalt-60 gamma radiation  and  monochloramine on
aqueous suspensions of Escherichia coli indicates at most an additive ef-
fect.  Thus, unless  a significant synergistic effect  can be  demonstrated
when radiation is used in combination with another disinfectant, radiation
disinfection costs  appear prohibitive  for  general wastewater  treatment.
                                     37

-------
Low ptH as a Disinfectant

    Exposure of microorganisms to extremes in hydrogen ion concentration
is a relatively ineffective method of disinfection.  It is known that Escheri-
chia coli can withstand  a pH  1-2  environment for one  hour witH only  a
75-80% loss in viability.  Salmonella typhosa is somewhat more sensitive.
A pH value of 4-5 is ineffective in reducing the viable count of these organ-
isms.  These statements are further substantiated when one considers that
enteric bacteria must survive the -extreme acid pH of the stomach before
entering the small  intestine.   Thus,  for low  pH to be a  truly effective
disinfectant,   extreme acidity .mast persist for a  considerable  period  of
time.
                                     38

-------
                                  TABLE VIII

                               COST SUMMARY
PLAN'!' SlX/Ji,  IV1C.D

CAPJTAJ,  COST

PROCESS

  Chlorine
  Chln<-/ A ir
   (l-.'.i.n,:-/()  <, /•;< .-i
1
$K
GO
70
120
640
1'JO
160
70
f>0
1, 450
. . Q ! j
•'•'  Teri.iui\y ( r'.-^
                                       55.90        20.20        14.00

                               ir, not incliulod in lh<::::<.' costs.

-------
C hi "ri.no
                               TABLE IX

           SUMMARY ON TIIK  STATUS OF DISINFECTANTS
                            Stnle-of      KiKM-gy   Health
                             iho-Art    KW.li/MG KJTc.cLs
Operational    HO
Sodium "nynix.-hlori.itt       Operrational   XCO
     'iiK'/Sull"'.!)- "Dioxido    C Operational     90
                             1'Miloi. Plant.   HO
                                                    ( Mij
                                                    C)i'{(anics
                                                     Or gun- OK:
                                         Toxrc
                                         Efl'ccl:
                                           Lo\v
                                           Lo\v
                             Pilot Plant.   8u()      Tini-;riown
                                           Lov/
                             Pilot Plant   409      Uul;no\vn
                                           Lo\v
                                   Plan!    3-iO.      A
                             Filc-H Plant.     90
                                       40

-------
     APPENDIX A  - RESEARCH AND DEVELOPMENT PROJECTS

    Listed below  are brief descriptions of EPA research projects on
    disinfection.

I.  On Going Projects

     A. "Parallel  Ozonation and   Chlorination with   DechlorLnation of
           Chlorinated  Effluent." Project  No.  802292,  City  of Wyoming.

              A study  on  disinfection effectiveness and bioassay effects of
           chlorine, ozone,  dechlorination with suflur dioxide and" bromine
           chloride. Estimated completion date,  Jan.  1976.

     B. "Ultraviolet Disinfection  of  Municipal Effluents",   Project  No.
           803292,  City of Dallas.

              The evaluation of ultraviolet light as a disinfectant for waste-
           water.

     C. "Reduction of Toxicity Emission Rates from Wastewater Treat-
           ment Plants  by   Optimization  of  the   Chlorination  Process."
           Project No.  803459, State of California.

              Develop  cost effective design parameters for the chlorination
           process.

    ^ D. "Multicell Lagoons  -  Micro Organism Removal Efficiency and
           Effluent Disinfection", Project No. 803294, Utah  State Univer-
           sity

              Define the lagoon equivalency  to disinfection and determine
           whether  chlorination will affect the organic content of effluent.

     E. "A Comparative Study  of  the Inactivation of Viruses in  Waste,
           Renovated  and Other  Waters  by  Chlorine  and Chlorine Com-
           pounds". Project No. 800370, University of Cincinnati.

              Determine  the  capability of  chlorine and  chlorinated com-
           pounds to destroy viruses in wastewaters.

     F. "NewMicrobial Indicators of Wastewater Chlorination Efficiency",
           Project No.  800712, University of  Illinois.

              Develop  a biological indicator that is more suitable and reli-
           able than the coliform group.  Report No.  EPA 670/2-73-082.

     G. "Ozone Contactor Study",  AWTRL Pilot Plant,

              An evaluation of ozone contactor efficiencies.
                                    41

-------
II.  Completed Projects

      A.  "The Detection  and Inactivation of Enteric Viruses in Waste-
          water", Project No. 800990, Hebrew University.

              Develop effective and economical procedures for  the in-
          activation of viruses in wastewater by ozone.

      B.  "Batch   Disinfection of   Treated Wastewater with Chlorine at
          Less Than 1 C,"  Project 16100 GKG, Arctic Environmental
          Research Laboratory,  Report No. EPA-660/2-73-005.

      C.  "Lime Disinfection of Sewage Bacteria at Low Temperature",
          Project 16100  PAK, Colorado State University, Report No.
          EPA-660/2-73-017.

      D.  "Hypochlorite Generator for  Treatment  of Combined Sewer
          Overflows",  Report No.  11023 DAA 03/72,  Ionics Incorpor-
          ated.

      E.  "Ultraviolet Disinfection of Activated Sludge Effluent Discharg-
          ing to Shellfish Waters",  Project No. WPRD 139-01-68, The
          Town of St. Michaels.

      F.  "Disinfection of Sewage  Effluents'',  Project No.  17060 DNU
          University of Illinois,    Bromine and  Chlorine Disinfection
          Results.

      G.  "Demonstrate Effectiveness of Iodine for the Disinfection of
          Public Water Supplies",  Project  No.   19-06-68,   City of
          Gainesville.

      H.  "Hypochlorination  of Polluted  Stormwater   Pumpage at New
          Orleans",    Report No.   EPA-670/2-73-067,  Pavia-Byrne
          Engineering Corporation, New Orleans,  La.

      L    Bench-Scale High-Rate Disinfection of Combined Sewer Over-
          flows with Chlorine and Chlorine Dioxide'1, Project No. 802400,
          O1 Brien and Gere Engineers, Inc. Syracuse,  New York.
                                    42

-------
       APPENDIX B - STATE STANDARDS (EXISTING)

A.  Water Quality

    -  Coliform limitations based on stream use of basin designation:
       all States  except one.

    -  Seasonally or hydrqgraphically based:  9  States.

    -  General toxicity standard applied thru permits:  9 States.

    -  Maximum chlorine residual standard applied thru permits:  6 States.

    -  State maximum chlorine residual limitations: . 3 States.

B.  Disinfection

    -  Year-round disinfection:  21 States.

    -  Universal disinfection with case-by-case exceptions:  1 State.

    -  Case-by-case disinfection requirements: 19 States.

    -  No specific requirements: 1 State.

    -  Secondary treatment - no specific disinfection requirment:  19 States.

    -  No standards: 8 States.

    -  Munimum chlorine residual: 5 States.
                                  43

-------
                            APPENDIX C
TABLE I.  Tentative Identifications and Concentrations of Chlorine-
          Containing Constituents in Chlorinated Effluents
                                                 concentration of
                                                 Orcianic Compound
             Identification          a              (up/liter)

        5-Chlorouracil                                  4.3
        5-Chlorouridine                                1.7
        8-Chlorocaffeine                               1.7
        6-Chloroguanine                                0.9
        8-Chloroxanthine                               1.5
        2-Chlorobenzoic acid                           0.26
        5-Chlorosalicylic acid                         0.24
        4-Chloromandelic acid                          1.1
        2-Chlorophenol                                  1.7
        4-Chlorophenylacetic acid                      0.38
        4-Chlorobfinzoic acid                           1.1
        4-Chlorophenol                                  0.69
        3-Chlorobenzoic acid                           0.62
        3-Chlorphenol                                  0.51
        4-Chlororesorcinol                             1.2
        3-Chloro-4-hydroxy-benzoic acid                1.3
        4-Chloro-3-methyl-phenol                       1.5
                                     44

-------
TABLE II.  Organochlorine Compounds in Hater from Sewaae Treatment Plant
Concentration Cwg/1)
Influent Effluent Effluent
before before after
Compound Treatment Chlorination Chlorination
Methylene chloride
Chloroform
1 ,1 ,1-Trichloroe thane
1 ,1 ,2-Trichloroethylene
1 ,1 ,2,2-Tetrachloroethylene
£ Dichlorobenzenes
£ Trichlorobenzenes
8.2
9.3
16.5
40.4
6.2
10.6
66.9
2.9
7.1
9.0
8.6
3.9
5.6
56.7
3.4
12.1
8.5
9.8
4.2
6.3
56.9
3A11 confirmed by GC-MS
                                    45

-------
TABLE III.  Trihalogenated Methane Content of Water from Water Treatment
            Plant
Sample Source Sampl'rng
Point
Kaw river water ;i
River water treated with 2
thlorine and alum-
chlorine contact time
A' 80 min.
3-day-old settled water 3
Water flowing from 4
settled areas to filters'3
Filter effluent 5
'Finished water 6
Free
Chlorine
ppm
u.u
6
2
2.2
Unknown
1.75
Concentration
Bromo
Ghloro- dichloro-
fonp methane
O.y
22.1
60.8
127
83.9
94.0
a
6.3
18.0
21.9
18.0
20.8
lug/i)
Dibromo-
chloro-
methane
a
0.7
1.1
2.4
1.7
2.0
   JNone  detected.   If  present,  the  concentration is     0.1  uq/1.

   ^Carbon slurry added at this  point.
                                     46

-------
                            TABLE IV

      SOME RECOGNIZED AND SUSPECT CARCINOGENS FOUND
                  IN MUNICIPAL WATER SUPPLIES
CHEMICAL

Bis (2-Chloroethyl) Ether
Chlorodibromome thane
Bromoform
Benzene
Carbon Tetrachloridc R
Bis Chloromethyl Ether R
Chloromethyl Methyl EtherR
Chloromethyl Ethyl 1,'ther
                                       ASSOCIATED WATERWAY

                                        Ohio River
                                        Ohio River
                                        Ohio River
                                        Ohio River and Wabash River
                                        Ohio River
                                        Ohio River
                                        Ohio River
                                        Ohio River
R
*
recognized carcinogen
decomposes readily
                                   47

-------
 TABLE V.  Halo-organic  Compounds  Identified 1n Drinking Waters in the
           United  States  (as  of  11/25/74)
  1.  acetylene dichloride
  2.  aldrin
  3.  atrazine
  4.  (deethyl)-atrazine
  5.  bromobenzene
  6.  bromochlorobenzene
  7.  bromodichloromethane
  8.  bromoform
  9.  bromoform butanal
 TO.  bromophenyl phenyl  ether
 11.  carbon  tetrachloride
 12.  chlordan(e)
 T3.  chlorobenzene
 74.  chlorodibromomethane
 15.  1,2-bis-chloroethoxy  ethane
 16.  chloroethoxy ether
 17.  bis-2-chloroethyl ether
 T8.  b-chloroethyl  methyl  ether
 19.  chloroform
 20.  chlorohydroxy  benzophenone
 21.  bis-chloroisopropyl ether
 22.  chlororcethyl ether
 23.  chloromethyl ethyl  ether
 24.  m-chloronitrobenzene
 25.  3-chloropyridine
 26.  DDE
.27.  DDT
 28.  dibromobenzene
 29.  dibromochloromethane
 30.  dibromod.ichloroethane
 31.  1,4-dichlorobenzene
 32.  dichlorodifluoroethane
 33.  1,2-dichloroethane
 34.  dichloroe.thyl  ether
 35.  dichloromethane
 36.  dieldrin
 37.  heptachlor
 38.  heptachlor  epoxide^
 39.   1,2,3,4,5,7,7-heptachloronorbornene
 40.  hexachlorobenzene
 41.  hexachloro-1,3-butadiene
 42.  hexachlorocyclohexane
 43.  hexachloroet'hane
                                      48

-------
TABLE V (cont.)
44.  methyl chloride
45.  octyl chloride
46.  pentachlorobiphenyl
47.  pentachlorophencl
48.  1,1,3,3-tetrachloroacetone
49.  tetrachlorobiphcnyl
50.  tetrachloroethare
51.  tetrachloroethylene
52.  trichlorobenzene
53.  trichlorobiphenyl
54.  1 ,T ,2-trichlorocthane
55.  1,1,2-trichloroethylene
56.  trichlorofluorofrethane
57.  2,4,6-trichlorophenol
                                      49

-------
                             CHLORINE ALUM
                                  SETTLED WATER
                                  •AVERAGE AGE
                                  3 DAYS
                              CHLORINE
                              CARBON SLURRY
                              FILTER
                              CHLORINE

                              -FINISHED WATER'
                                    INDICATES
                                    SAMPLING- POINT
Figure i. WATER TREATMENT PLANT SAMPLING POINTS
                        50

-------
                          APPENDIX U
                      SECTION IV REFERENCES
1.  Geldreich,  E.E., "Water Borne  Pathogens in Water  Pollution Micro-
   biology ed R. Mitchel, Wiley-Interscience, New York,  1972 p. 207-235.

2.  Flynn,  M. J. and Thistlewayfe,  D. K. B.,   " Sewage  Pollution and Sea
   Bathing", Second International Conference on Water Pollution Research,
   1964.

3.  Morbidity and Motality Weekly Reports.   "Shigellosis Associated with
   Swimming in the Mississippi River" ,  National Center for Communicable
   Disease,  U. S. D. H. E. W., Vol. 23, No. 46,  1974

4.  Ibid.  Morbidity and Mortality  Weekly Reports.   "Hepatitis in .Camps  -
   Florida".  National Center for Communicable Diseases,  U. S. D.H. E. W.,
   Vol.  20,  No. 26, 1971.

5.  Jones,  E.H. "External Otitis,  Diagnosis and Treatment",  C. C. Thomas
   Publications,  Springfield,  Illinois, 1965.

6.  Fisher,  L. M.,   1937, "Report of the Committee on Shellfish", Public
   Health Engineering Section, American Public Health Association,  Am.
   J. Publ.  Hlth 27:180-196,  Supplement march 1973.

7.  Mosely,  J. W.,  "Epidemiological Aspects of Microbial Standards for
   Bathing Beaches",  International Symposium on Discharge of Sewage
   from Sea Outfalls,  London, England, August  1974,  Paper No. 9.

8.  National  Shellfish Sanitation Program Manual of Operations.   Part I,
   Sanitation of Growing  Areas,   U. S. Department of Health, Education
 •  and Welfare,  Shellfish Sanitation  Branch,  Washington,  D.C.,  1965,
   p. 36

9.  Hunt, D.A. and Springer,  J. 1975,  Preliminary Report on A Compar-
   ison of Total Coliform and Fecal Coliform Values in Shellfish Growing
   Areas and a Proposed Fecal Coliform Growing Area  Standard."  Pre-
   sented at the 8th National Shellfish Sanitation Workshop,  F.D. A.,
   Washington, D.C.

10. National Technical Advisory Committee,  Water Quality Criteria, Fed-
   eral  Water Pollution Control Administration, Department of Interior,
   Washington, D.C., 19£8,  pp.  7-14

11. Cabelli,  V.J.,   M.A.  Levin,   Dufour,  A. P.  and McCabe, L. J. "The
   Development of Criteria  for Recreational Waters", International Sym-
   posium on Discharge  of Sewage from Sea Outfalls, London,  England,
   August 1974, Paper No. 7.

                                    51

-------
12; National   Academy  of  Sciences,   "Water Quality Criteria 1972",
    Washington, D. C.

13. Lui,  O. and McGowan,  F., Northeastern  U.S. Water Supply  Study
    Potomoc Estuary Water Supply:  A Consideration of Viruses,  U.S.
    Army Eng. Div.,  N. Atlantic, 1970.

14. Chambers, C.W.,  1971, "Chlorination for Control of Bacteria and
    Viruses in Treatment Plant Effluents",  Jl.  Water  Poll.  Control.
    Federation. 43:228-241.

15. Scarpino,  P. V.,   "Human Enteric Viruses  and Bacteriophages as
    Indicators  of Sewage Pollution", International Symposium on Dis-
    charge of  Sewage from Sea .Outfalls,  London,  England, August 1974,
    Paper No.  6

16. Chang,  C.M.,    Boyle, W. C.  and  Goepfent,  J. M., "Rapid Quanti-
    tative Method for Salmonella Detection in Polluted Waters ', Applied
    Microbiol. 1971, 21:662,

17. Merrell,  J. C.  et al. 1967, "The Sante Recreation Project",  Sante
    California, F.W.P.C.A., D. I.,  WP -20-7

18. Velz, Clarence J.,  "Applied Stream Sanitation", Wiley-Interscience,
    New York, 1970, p.  17.

19, Jackson, S,, 1974, "Disinfection of Secondary Effluent with Bromine
    Chloride", Workshop on Disinfection  of Wastewater and  its Effect
    on Aquatic Life", Grand Rapids,  Michigan..

20. Rosen,  H. M.,   Lawther,  F. E.  and Clark,   R.G.,  1974,  "Getting
    Ready for Ozone",  Water and Waste Eng.  ll(Jul):25.

21. Kelly,  S.  and  Sanderson,  W.W.,  1960,  "The Effect of  Combined
    Chlorine on Poliomyelitis and Coxsachie Viruses",  A.J. P.H.  50:14.

22. Clarke, N..A. et al. 1964, "Human Enteric ..Viruses in Water", Source
    Survival and Removability in;   Adv. Water  Pollution  Res. Vol2.,
    McMillan,  New York.

23. Shuval,  H.I. et al.  1966,  "The Inactivation of Enteric Viruses in
    Sewage by ChTormation  in:  Adv.   Water Pollution Res., Vol. 4,
    McMillan, New York.

24; Craun,  F.G.  and  McCabe, J. L. "Review of  the Causes of Water-
    borne-Disease  Outbreaks",  JAWWA 65, 74(1973)
                                     52

-------
25. Craun,  K.G.  and McCabe,  J. L.  "Outbreaks of Waterborne Disease in
    the United States",  1971-1972, The Journal of Infectious Diseases,  Vol.
    129, 614,  May 1974.

26. Mason, J.O.,  and McLean, W. R.,  1962,  "infectious Hepatitis Traced to
    The Consumption of Raw Oysters", Am.  J. Hyg.  75:90-111

27. Pameroy, R. D.,  "Empirical Approach for Determining Required Length
    of an Ocean Outfall",  Proc.  1st.  Int. Conf.  Waste Disposal Mar. Env.
    Pergamon Press,  London,  1960.  pp. 268-278.

28. Gunnerson, C.G.  "Discharge of Sewage from Sea Outfalls",  London, Aug.
    1974,  Paper No.  41.

29. Pearson, E. A.,  "Conceptual Design of Marine Waste Disposal System",
    Int. Symp.  on Discharge of Sewage from  Sea Outfalls,   London, Aug.
    1974,  Paper No.  40.

30. Cabelli, V., EPA National Marine Water Quality Laboratory, Narragan-
    sett, R.I., Personal Communication.

31. Jolly,  R. W.  " Chlorination Effects on  Organic Constituents in Effluents
    from Domestic Sanitary Sewage Treatment Plants",  Oak Ridge National
    Laboratory, October, 1973

32. Ajami,  A.M.  "Review  of the Environmental Impact of Chlorination and
    Ozonation By-products",  Eco-Control,  Inc., Cambridge,  Mass.,  June,
    1974.

33. Bellar,  T.A., Lichtenberg,  J. II. and Kroner,  C.R.,  "The Occurrence
    of Organohalides  in Chlorinated Drinking Waters",  EPA-670/4-74-008,
    November, 1974

34. Rook,  J. J.,   "Formation of Haloforms  During  Chlorination of  Natural
    Waters",  The Journal  of the  Society for Water Treatment and Examina-
    tion, Vol. 23,  part 2, p. 234 (1974)

35, Kraybill,  H.F.,  "The  Distribution of Chemical Carcinogens in  Aquatic
    Environments",  National Cancer Institute, October, 1974.

36. Little,  A.D.  Inc., Cambridge, Mass., "Organic  Chemical Pollution of
    Freshwater",  EPA //18010 DPV 12/70.

37. McCabe, L.  and Tardiff,  R., Derived  from  a  Paper presented before
    the DHEW  Committee to Coordinate Toxicology and Related Programs,
    November, 1974.
                                    53

-------
3B.. Snoeyink, V.L.,  etal.  A-ctive Carbon: Dechlorination and the Adsorption
    of Organic Compounds11,  Chemistry of Water  Supply Treatment  send
    Distribution, A. J. Rubin, Ed.,  Ann Arbor Science,  1974.

39. Pair, G.M. and Geyer, J.C.,  "Water Supply and Waste-Water Disposal",
    John Wiley and Sons,  1954.
                                     54

-------
                      SECTION V - REFERENCES

1.  Mcrkens,  J.  C.,  "Studies on the Toxicity of Chlorine and Chloramines
   to the Rainbow Trout. "Water & Waste Trt. Jour. (G.B. ), 7.  150(1958).

2.  Doudoroff,  P.,  and  Katz,  M. ,  "Critical Review of Literature on the
   Toxicity of Industrial Wastes  and Their Components to  Fish. " Sew.  &
   Ind. Wastes,  22, 1432 (1950).

3.  "Chlorinated  Municipal Waste  Toxicities to Rainbow Trout and Fathead
   Minnows. " Mich.  Dept. of Natural Resources, Water Poll. Control Res.
   Ser. , 18050 GZ2, EPA,  Washington, D. C. (1971).

4.  Tsai, C.,  "Water Quality and Fish Life Below Sewage Outfalls. " Trans.
   Amer.  Fish.  Soc., 102, 281 (1973).

5.  Arthur,  J. W.,  et al.,  "Comparative  Toxicity of Sewage-Effluent Dis-
   infection to FresKwaFer Aquatic  Life. " Water Poll.  Control Res.  Ser.
   EPA, Washington,  D.C.  (1975).

6.  Esvelt, L. A., et al., "Toxicity Removal from Municipal Wastewaters. "
   Vol. IV,  "A Stud~y~of  Toxicity and Bio stimulation in San Francisco  Bay-
   Delta Waters. "    SERL Rept.   No. 71-7,  San  Eng.  Res. Lab.,  Univ.
   of California, Berkeley (1971).

7.  Esvelt,  L. A. , et al., "Toxicity Assessment of  Treated Municipal Waste-
   water. " Jour. Wafer Poll. Control Fed., 45, 1558(1973).

8.  Krock,   H.,  and  Mason,  D. T. ,  "Bioassay of Lower Trophic Levels."
   Vol. VI,  "A Study  of  Toxicity and Biostimulation in San Francisco  Bay-
   Delta Waters. "  SERL Rept.  No.  71-8,  San Eng.  Res.  Lab.,  Univ.
   of California, Berkeley (1971).

9.  Martens,  D.  W., and Serviai, J. A., "Acute Toxicity of Municipal Sew-
   age to Fingerling  Sockeye Salmon. "  International Pacific Salmon Fish-
   eries Commission  Progress  Report No.  29, New  Westminster,  B.C.
   18 p (1974).

10.  Servizi, J.  A.  and  Martens,  D. W.,  "Preliminary Survey of Toxicity
    of Chlorinated Sewage to Sockeye and Pink Salmon. "  International Paci-
    fic Salmon Fisheries Commission Progress Report No. 30, New West-
    minster,  B.C.  42 p  (1974).

11.  Enoeyink, V. L. ,  and Markus,  F. I. ,  "Chlorine Residuals in Treated
    Effluents."  Watep & Sew.  Works,  121, 35(1974).

12.  McKersie,  J.,  "A  Study  of Residual  Chlorine below  Selected Sewage
    Treatment Plants in Wisconsin,  Summer,  1974. "  Wise.  Dept. of Nat.
     Res. Water Quality  Evaluation Section,  Mimeo  18 p (1974).


                                  55

-------
13.  Nebel,  C. ,  et  al.,  "Ozone Disinfection of Industrial-Municipal Secon-
     dary Effluents. """Jour. Water Poll.  Control Fed.  45,  (1973).

13.  Holland,  G. A. et al. ,  "Toxic Effects  of Organic Pollutants on young
     Salmon and TrouTT "~~ Wash.   Dept.  Fish.,  Res. Bull. No. 5. 260  p
     (1960).

15.  Alderson,  R. ,  "Effects -of Low Concentrations  of Free  Chlorine On
     Eggs and Larvae of 3Rlaice, Pleutonect.es platessa L.  "  In:. Marine  Pol-
     lution and  Sea  Life.  "Fishing  News,  Ltd.,  LondorTp  312-315  (1972).

.tJB.  Muchmore,  D.  amd B.  Epel. , "The Effects of Chlorination of Waste-
     water on   Fertilization in .Some  Marine Invertebrates. "   Mar. Biol.
     19:93-95 (1973).

•17.  Galtsoff,   P.  S. , "Reactions of Oyste-rs lo Chlorination. " USFWS,  Res.
     Rpt. 11 (1946).

18.  Tsai,  C. ,  "Effects of Chlorinated Sewage  Effluents on  Fishes in Upper--
     Patuxent River, Maryland. " Chesapeake Sci. 9:83-93(1968).

IB.  Tsai,  C.,  "Changuss  in  Fish  Populations  and Migration in Relation to_
     Increased Sewage Pollution in  Little Ratux-ent River,  Maryland. " Ches-
     apeake Sci. 11:34-41 (1970).

20.  Waugh,  G.D.,  "Observations on the -Effects  of Chlorine on the  Larva**
     of Oysters, Ostr.ea edulis L. ,  and Barnacles Elminius  modestus,  Dar-
     win. " Ann.  Appl. .Biol. 54r??3-440 (1964).

21.  McLean,   R.  I.,  "Chlorine and Temperature  Stress in Estuarine Inver
     tebrates. " Jour. WPCF.  45:837-841 (1-973).

22.  Carpenter,  E.  J.,, B.B. Peck and S.  J.  Anderson.,  "Cooling Wate
     Chlorination and IRroductivity of Entrained Phytoplankton. " Mar. Bio]
     16:37-40 (1072).

"23.  Hiray.ama, K.  and iR. ZHmana. .,  "inHuences  of High  Temperature  aj
     Residual  Chlorine  on Marine Phytopfcankton.. "   Mar.  Biol.  7:205-21.3
     (1970).
24.  Gentile, J. H.,  J.  Cardin,  M. Johnson and S. Sosnowski. ,  "The
     of Chlorine  on  thfe Growth and Survival of Selected Species of Estuarine
     Phytoplankton and Zooplankton.  "  Unpublished Manuscript (1972).
                                   56

-------
25.  Gentile,  J.  H., S. Cheer and N.  Lackie. ,  "The  Use of ATP in the
     Evaluation of Entrainment. " Unpublished Manuscript (1973).

26.  Basch,  R.  E. ,  and Truchan,  J.  G.,  "Calculated Residual  Chlorine
    Concentrations  for  Fish. "  Michigan Water Resources Commission,
     Lansing,  Michigan.  29 p (1974).

27.  Ell*AC, "Report  on  Chlorine and Freshwater Fish."  European Inland
     Fisheries  Advisory  Commission  Technical  Paper No.  20,  Food  and
     Agriculture Organization of the United States, 11 p (1973).

28.  Brungs,  W.  A. ,  "Effects of Residual Chlorine on Aquatic Life. " Jour.
     Water Poll.  Control Fed. 45, 2180 (1973).
                                  57

-------
                    SECTION VI REFERENCES
 1.  "Summary  Report:   The  Extent of Shortages for Chlorine and Other
     Water Sanitation Chemicals. "  U.S. Environmental Protection Agency
     (April 1974)

 2.  "Chlorine - Its Manufacture  Properties and Uses."  J. S.  Sconce (Ed)
     American  Chemical Society Monograph Scries No. 154 Reinhold Pub.
     Corp.,  New York (1962).

 3.   Brezenski, F. T-, et al. "The Occurrence  of Salmonella and Shingella
     in Post-ChlorinatecTand Non-Chlorinated Sewage Effluents and Receiv-
     ing Waters."  Health Lab. Sou, 2, 40 (1965).

 4.   Chambers, C.W., "Chlorination for Control of Bacteria and Viruses in
     Treatment Plant Effluents"   Jour. Water Poll.  Control Fed.,  43,  230
     (1971)

 5.   Scarpino,  P.V., et al. "Destruction of Viruses and Bacteria in Water
     by Monochlorimine" Tin Press,  Proc. 7th Intnl. Conf. Water Poll. Res.
     Presented  in Sept.  1974,  Paris]  France.

 6.   Scarpino,  P.V.,  et  al. WA Comparative Study of the Inactivation of
     Viruses in Water~"T>y~~ChIorine"   Water Res.  (G. B.)  6,  959 (1972).

 7.   Smith,  R.,  ej,  al.  "Cost  of  Alternative  Processes  for  Wastewater
     Disinfection"   Presented - Workshop on  Disinfection of  Wastewater
     and Its Effect on  Aquatic   Life,   Wyoming,.  Michigan.  (Oct.  1974).

 8.  "Disinfection  of  Wastewater  with  Sodium Hypochlorite" Chapter  VII,
     (Author -  T.  Kennedy -  Chicago  Metro. Sanitary  District)  Manual of
     Practice for  Chlorination of Wastewater,  Water Poll.  Control Fed.
     In press.                               "

 9.   Baker, R.J.,. " Characteristics of Chlorine Compounds" Jour. Water
     Poll. Control Fed., jU 482 (1969).

10.    Baker,  R. J.. (Wallace and Tiernan Co.  -Belleville, N. J. )  Personal
     Communication (Jan.  2, 1975).

11.    White, George Clifford,  "Handbook of Chlorination"   Van Nostrand-
      Reinhold New York (1972).

12.    Personal  Communication to:     W.  McMichael,  AWTRL,   NERC-
     Cincinnati (Oc-l.  1974).
                                     58

-------
13.  "  Process  Design Manual for Carbon Adsorption."   Environmental
       Protection Agency, Technology Transfer,  October, 1973.

14.    Collins,  H. F. et al. "interim Manual for Wastewater Chlorination
       and DechlorinationTractices",' California State Department of Health,
       February, 1974.

15.  "Ammonia  Removal  in  a Physical- Chemical Wastewater Treatment
       Process,   Environmental Protection  Agency,  No EPA-R2-72-123,
       November,  1972.

16.    Lee,  J. S. e_t al. "Ozonation as an Alternative to Chlorination for the
       Disinfection~bTTreated Wastewaters, Metropolitan Sewer Board  of
       the Twin Cities, October,  1973.

17.    Mittler,  S.  et al. "Toxic ity  of  Ozone",  Ozone Chemistry  and  Tech-
       nology American Chemical  Society,   Washington,  D. C.  1959, pp.
       344-351.
18.   Greening,    E.  "Feasibility  of Ozone Disinfection of Secondary
      Effluent,"  Illinois Institute for  Environmental Quality,   IIEQ No.
      74-3, January,  1974.

19.   Huff, C. B.  et al. "Study of Uliraviolet Disinfection of Water and Fac-
      tors in  Treatment Efficiency ^',.,Pjit>Uc Health Reports, August 1965,
      volume 80,  number 8, pp 695-705, "                 '

20.  " Facts You Should Know About XHtfadynamics",  Brochure  by Ultra-
      dynamics Corporation,  Pattersdn,' N. J.

21.  " Ultraviolet  Disinfection of  Activated Sludge Effluent Discharging to
      Shellfish Waters", Draft Report, Project WPRD 134-01-68.

22.   Filbey,  A.H.,   "Bromine Chloride as an Alternate Disinfectant",
      Chlorine Residual Policy Seminar, State .of Maryland> November,
      1974.

23.   Jackson,  S. C.   "Chlqrobromination of Secondary Sewage Effluent"
      Dow Chemical  Company, December,  1974.

24.   Walkenhuth,  E.G. e_t al. "An Investigation of Bromine Chloride as a
      Biocide in  Condenser  Cooling : Water,  35th Annual Meeting Inter-
      national Water  Conference, Pittsburgh,  Pennsylvania, October, 1974.
                                     59

-------