EP
Group I, Phase II
      Developmental Document for
   Effluent Limitations Guidelines and
   New Source Performance Standards
                for the
  OTHER  NON-FERTILIZER
 PHOSPHATE   CHEMICALS
             Segment of the
           PHOSPHATE
       MANUFACTURING
         Point Source Category
                 **
     UNITED STATES ENVIRONMENTAL
          PROTECTION AGENCY
                JUNE 1976

-------

-------
        DEVELOPMENT DOCUMENT FOR
    EFFLUENT  LIMITATIONS GUIDELINES
  AND NEW SOURCE PERFORMANCE STANDARDS
                 FOR THE
     OTHER NON-FERTILIZER PHOSPHATE
        CHEMICALS SEGMENT OF THE
        PHOSPHATE MANUFACTURING
         POINT SOURCE CATEGORY
            Russell E. Train
             Administrator

         Andrew W.  Breidenbach
   Assistant Administrator for Water
        and Hazardous Materials

            Eckardt C. Beck
   Deputy Assistant Administrator for
      Water Planning and Standards
           Robert B.  Schaffer
 Director, Effluent Guidelines Division
            Chester E.  Rhines
             Project Officer

                June 1976
      Effluent  Guidelines Division
Office of Water and Hazardous Materials
  U.S. Environmental Protection Agency
        Washington,  D.C.  20460
   For sale l)y the Superintendent of Documents, U.S. Government Printing Oilier
             Washington, D.C. 20401' - Price $1.80

-------

-------
                          ABSTRACT
A study was carried  out  on  the  non-fertilizer  phosphate
chemical segment of the phosphate manufacturing point source
category  for  the purpose of developing effluent limitation
guidelines, federal standards of performance, and  pretreat-
ment  standards.   This  was done to implement sections 304,
306, and 307 of the Federal  Water  Pollution  Control  Acts
Amendments of 1972.

The  study included a detailed and extensive exemplary plant
survey, contacts with consultants and government  officials,
and literature search.

The   industry   survey   involved  data  gathering,  sample
collection  and  analysis,  and  personal  visitation   with
responsible  plant  operating personnel to obtain first-hand
information on treatment technology in  commercial  use  and
technology in development and pilot plant stages.

The  three  main  outputs  from  the  study  were:  industry
subcategorization, recommendations on  effluent  guidelines,
and  definition of treatment technology.  The non-fertilizer
phosphate chemicals consisted of three  subcategories  which
were  considered  separately  for more meaningful separation
and  division  of  waste  water  treatment,  and  subsequent
development of effluent guidelines.  These subcategories are
defluorinated  phosphate rock, defluorinated phosphoric acid
and sodium phosphates.  Notice  of  interim  final  effluent
limitations guidelines has been drafted for existing sources
for  both  best  practicable  control  technology  currently
available, and for best  available  technology  economically
achievable.  Notice of proposed standards of performance for
new   sources  and  notice  of  pretreatment  standards  for
existing sources and for new  sources  has,  likewise,  been
drafted  for  each subcategory  (FR 40, 4102 and FR 40, 4110,
January 27, 1975).  The interim final regulations have  been
amended  and promulgated for existing and new sources in the
Federal  Register  notice  associated  with  this  document.
Pretreatment standards are being reserved at this time.

Treatment  technologies such as in-process or end-of-process
add on units are available singly or in combination to  meet
the recommended effluent guidelines.
                         111

-------

-------
                           Index
TITLE PAGE

ABSTRACT

TABLE OF CONTENTS
Section I

Section II

Section III

Section IV

Section V

Section VI

Section VII

Section VIII


Section IX



Section X



Section XI


Section XII

Section XIII

section XIV
Conclusions

Recommendations

Introduction

Industry Subcategorization

Waste Characterization

Selection of Pollutant Parameters

Control and Treatment Technology

Cost, Energy and Non-Water
    Quality Aspects

Best Practicable Control Technology
    Currently Available, Final
    Guidelines and Limitations

Best Available Technology Economically
    Achievable, Final
    Guidelines and Limitations

New Source Performance
    Standards and Pretreatment Standards

Acknowledgments

References

Glossary
Page

  1

  5

  9

 21

 23

 45

 57


 71



 79



 89


 93

 99

 101

 105

-------

-------
                      FIGURES
                                                        Page
 III-l         Defluorinated Phosphate Rock
                  Plant Locations                        17

 III-2         Defluorinated Phosphoric Acid
                  Plant Locations                        18

 III-3         Sodium Phosphates Plant Locations         19

  V-l          Defluorinated Phosphate Rock
                  Fluid Bed Process                      24

  V-2         Defluorinated Phosphoric Acid
                  Vacuum Process                         33

  V-3         Defluorinated Phosphoric Acid
                  Submerged Combustion                   34

  V-4         Defluorinated Phosphoric Acid
                  Aeration Type                          35

  V-5         Sodium Phosphate Process from
                  Wet Process Phosphoric Acid            40

VII-1         Contaminated  (Pond) Water Treatment        64
                      vil

-------

-------
                        TABLES
                                                           Page
VIII-1          Water. Effluent Treatment  Costs              73

VIII-2          Summarized Estimated  Wastewater
                Treatment Costs of  Phosphate
                Manufacturing Plants                         74

 XIV-1          Metric Conversion Table                     106
                       1x

-------

-------
                         SECTION I


                         CONCLUSION


This  study  was  conducted  for  the  purpose  of extending
effluent limitations guidelines and standards of performance
to  all  the  major  chemical  products  of  the   Phosphate
Manufacturing  Point  Source  Category,  and was directed at
products  neither  covered  in   the   Phase   I   phosphate
manufacture   study,   nor  included  among  the  fertilizer
phosphate products.  The Phase I phosphate study covered the
production  of  phosphorus,  and   products   derived   from
phosphorus.   This Phase II study covers phosphate chemicals
produced  by  the  defluorination  of  phosphate  rock,  the
defluorination of phosphoric acid, and the sodium phosphates
produced    from   wet   process   phosphoric   acid.    The
subcategories  previously  established  for  the   Phosphate
Manufacturing Point Source Category were:

    The Phosphorus Derived Chemicals Segment

    Subpart A - Phosphorus Production Subcategory

    Subpart B - Phosphorus Consuming Subcategory

    Subpart C - Phosphate Subcategory.

    The  Other  Non-Fertilizer  Phosphate Chemicals Segment,
    now added, include:

    Subpart D - Defluorinated Phosphate Rock Subcategory

    Subpart E - Defluorinated Phosphoric Acid Subcategory

    Subpart F - Sodium Phosphates Subcategory

The study of  Subparts  A,  B  and  C  (Phase  I)   has  been
completed and regulations published in the Federal Register,
Title  40,  Part  422,  page  6580, February 20, 1974.  This
Phase II study deals only with Subparts D, E, and F.

The major waste water pollutant problems for Subparts  D,  E
and  F processes of phosphate chemicals manufacture are much
closer associated with  the  fertilizer  phosphate  industry
problems   than   with   Subpart   A,   B  and  C  phosphate
manufacturing problems.  The phosphoric  acid  raw  material
utilized  for  making  defluorinated  phosphoric  acid,  for
making  sodium  phosphates,  and  used  as  a   reagent   in

-------
defluorination  of  rock, is exclusively produced by the wet
phosphoric acid process.   "^he purification processes carried
on constantly in this segment create  fluoride  waste  water
problems.   Residues from salt purification processes contain
phosphate  residues along with salt contaminants that create
problems if recycled  indefinitely,  and  require  blowdown.
The contaminated water recycle pond, heart of the fertilizer
phosphate  waste  water  treatment system, provides the best
known means  of  dealing  with  most  of  these  components.
Fluorides,  sulfates and phosphates are precipitated by lime
treatment.  Under  favorable  water  balance  circumstances,
operation  is without discharge of process waste water.  The
radium 226 problem is similar  to  that  in  the  fertilizer
phosphate  industry.  Radium 226 can be and is controlled by
an adequately alkaline coagulation  reaction  and  effective
clarification  while  carrying  out the double lime effluent
treatment  process.    Extremely   rigorous   controls   are
essential to prevent flow into ground water through channels
left  open by improper lagoon lining operations.  Dikes must
be built and maintained in a manner that eliminates failure.
Dike failures have occurred in the slime ponds of  phosphate
mining operations and in phosphate manufacturing operations,
recirculation  and  reuse  ponds.  Dike failure is a serious
potential  hazard  from  contaminated  water  ponds.    Dike
failure  leads  to  massive  pollution  by at least 5 highly
objectionable  pollutants,  radium  226,  fluoride,   acidic
wastes,  phosphate  and  suspended  solids.  Recommendations
that drastically reduce the dike failure hazard are provided
in this development document.

The information on fertilizer phosphates in the  Development
Document  for Effluent Limitations Guidelines and New Source
Performance Standards for  the  basic  fertilizer  chemicals
segment  of the fertilizer point source category is fully as
important as the information  gathered  in  this  study  for
dealing  with  the  other non-fertilizer phosphate chemicals
segment  of  the  phosphate   manufacturing   point   source
category.    Practicable  treatment  is  available  to  these
manufacturing operations only  through  utilization  of  the
recirculation  and  reuse  lagoon  developed for waste water
treatment in wet phosphoric acid manufacture.

In  the  defluorinated  phosphate  rock  and   defluorinated
phosphoric  acid  processes  the  techniques  and  treatment
technologies do exist  and  are  commercially  practiced  to
achieve   essentially   no   process  waste  water  effluent
discharge  to  navigable  waters.   The  exception  to  this
situation   would  be  an  adventitious  condition  such  as
abnormal rainfall  accumulation.   Under  such  a  condition
treatment   technology  does  exist  to  treat  contaminated

-------
process waste waters for  reduction  of  contaminants  on  a
commerically  demonstrated  basis to the effluent limitation
guideline levels.

In the sodium phosphates process, technology does  exist  to
continuously  treat  the  process  waste  water  effluent to
commercially demonstrated levels that meet  the  promulgated
effluent limitation guideline levels.

In-process  modifications  and  end-of-process  plant  waste
water treatment technologies are in current  industrial  use
to    enable    new   non-fertilizer   phosphate   chemicals
manufacturing plants to  meet  the  promulgated  new  source
standards.

-------

-------
                         SECTION II
                      RECOMMENDATIONS

These amendments to the phosphate manufacturing point source
category  are  being introduced to include the defluorinated
phosphate rock subcategory  (Subpart  D),  the  defluorinated
phosphoric  acid  subcategory  (Subpart  E)  and  the sodium
phosphates subcategory  (Subpart F).

Final effluent limitations have been  written  for  existing
sources,  covering  both best practicable control technology
currently available (BPCTCA), and best available  technology
economically  achievable   (BATEA).   New  source performance
standards (NSPS)  have also been  promulgated.   Pretreatment
has been reserved.

The regulations are about to appear in the Federal Register;
the  Federal  Register  presents the regulations in official
form.

Defluorinated Phosphate Rock and Defluorinated Phosphoric
Acid Subcategories

The  effluent  guidelines  limitations   written   for   the
defluorinated  rock and the defluorinated acid subcategories
include specifications on the capacity of the  recirculation
and reuse lagoon.  The lagoon must maintain reserve capacity
to  retain  the  heaviest expected 24 hour rainfall for a 10
year (or 25 year) period.  The treated effluent that may  be
discharged  in  periods  of  excessive  rainfall  must  meet
specified concentration limits.   The  surge  capacity  must
hold  the  heaviest  expected  10  year 24 hour rainfall for
BPCTCA, and the heaviest expected 25 year 24  hour  rainfall
for  BATEA  and NSPS.   The guidelines written for the sodium
phosphates  subcategory  are  based  on  weight   units   of
pollutant per weight unit of product.

Concentrations  of pollutant components permitted in process
wastewater discharges for BPCTCA, BATEA and NSPS:

Effluent                         Effluent
Charact eristic                   Limitations

                    Maximum for     Average of daily
                    any one day     values for thirty
                                    consecutive days
                                    shall not exceed

-------
         (Metric units, mg/1)

Total phosphorus       105             35
  (as P)
Fluoride                75             25
TSS                    150             50
pH                      Within the range 6.0 to 9.5

The total suspended  solid  limitation  set  forth  in  this
paragraph  shall  be  waived  for  process wastewater from a
calcium  sulfate  storage  pile  runoff  facility,  operated
separately  or  in  combination  with  a water recirculation
system, which is chemically treated and  then  clarified  or
settled to meet the other pollutant limitation^ set forth in
this paragraph.

Concentration  of pollutants discharged in contaminated non-
process wastewater shall not exceed the values listed in the
following table:

Effluent                         Effluent
Ch a r a c ter i stic                   Limitations

                    Maximum for     Average of daily
                    any one day     values for thirty
                                    consecutive days
                    	     shall not exceed

                                  mg/1

Total phosphorus       105             35
  (as P)
Fluoride                75             25
pH                      Within the range 6.0 to 9.5

Pretreatment standards are reserved.

Sodium Phosphates Subcategory

The following limitations establish the quantity or  quality
of  pollutants  or  pollutant properties controlled by final
regulations  for   best   practicable   control   technology
currently available:

Effluent                         Effluent
Characteri stic                   Limitations

                    Maximum for     Average of daily
                    any one day     values for thirty
                                    consecutive days

-------
                                    shall not exceed
         (Metric units, kg/kkg of product)
         (English units, lb/1000 lb of product)
TSS
Total phosphorus
   (as P)
Fluoride
pH
0.50
0.80
0.25
0.40
0.30            0.15
Within the range 6.0 to 9.5
The  following limitations establish the quantity or quality
of pollutants or pollutant properties  controlled  by  final
regulations    for   best   available   control   technology
economically  achievable  and  for  new  source  performance
standards:
Effluent
Characteristic
                    Maximum for
                    any one day
         Effluent
         Limitations

            Average of daily
            values for thirty
            consecutive days
            shall not exceed
          (Metric units, kg/kkg of product)
          (English units, lb/1000 lb of product)
TSS
Total phosphorus
    (as P)
Fluoride
pH
0.35
0,56
0.18
0.28
0.21            0.11
Within the range 6.0 to 9.5
Pretreatment standards are reserved.

-------

-------
                        SECTION III
                        INTRODUCTION
Section  301(b)   of  the Act requires the achievement by not
later than July 1, 1977, of effluent limitations  for  point
sources,  other  than  publicly owned treatment works, which
are based on the application of the best practicable control
technology   currently   available   as   defined   by   the
Administration  pursuant  to  Section  304 (b)  of  the  Act.
Section 301 (b) also requires the achievement  by  not  later
than  July  1,  1983,  of  effluent  limitations  for  point
sources, other than publicly owned treatment  works.   These
are  to  be  based  on the application of the best available
technology economically  achievable  which  will  result  in
reasonable  further  progress  toward  the  national goal of
eliminating the discharge of all pollutants,  as  determined
in  accordance  with regulations issued by the Administrator
pursuant to Section 304 (b) of the Act.  Section 306  of  the
Act  requires  the  achievement  by new sources of a Federal
standard of performance providing for  the  control  of  the
discharge  of  pollutants which reflects the greatest degree
of effluent reduction which the Administrator determines  to
be  achievable through the application of the best available
demonstrated  control   technology,   processes,   operating
methods, or other alternatives, including where practicable,
a standard permitting no discharge of pollutants.

Section  304(b)   of  the  Act  requires the Administrator to
publish within one year of enactment of the Act, regulations
providing guidelines for effluent limitations setting  forth
the  degree  of  effluent  reduction  attainable through the
application of  the  best  control  measures  and  practices
achievable  including  treatment  techniques,  processes and
regulations proposed herein set forth  effluent  limitations
guidelines  pursuant  to  Section  304(b)  of the Act for the
fertilizer manufacturing category of point sources.

Section 306 of the Act requires  the  Administrator,  within
one  year  after a category of sources is included in a list
published pursuant to Section 306 (b)   (1)  (a) of the Act,  to
propose   regulations   establishing  Federal  Standards  of
performances for new sources within  such  categories.   The
Administrator  published  in the Federal Register of January
16, 1973 (38 F.R. 1624), a list  of  27  source  categories.
Publication  of  the  list  constituted  announcement of the
Administrator's intention  of  establishing,  under  Section
306,  standards  of  performance  applicable  to new sources

-------
within  the  fertilizer  manufactuirng  category  of   point
sources,  which  included  within the list published January
16, 1973.

The  effluent  limitations  guidelines  and   standards   of
performance  proposed  in  this  report  were developed from
operating data, sampling, and information gathered from  six
plants.   These  plants  represent a very high percentage of
the total number of the industrial units in two of the three
study processes.  The methods and  procedures  used  in  the
accumulation of the overall information are described in the
following paragraphs.

Summary  of  Methods  Used  for  Development of the Effluent
Limitations Guidelines and Standards of Performance

The  effluent  limitations  guidelines  and   standards   of
performance  proposed herein were developed in the following
manner.  The point source category was first studied for the
purpose of  determining  whether  separate  limitations  and
standards  are appropriate for different segments within the
category.  This analysis included a determination of whether
differences  in  raw  material   used,   product   produced,
manufacturing  process  employed,  age,  size,  waste  water
constituents, and other factors require development of sepa-
rate limitations and standards for different segments of the
point source category.

The raw waste characteristics for  each  such  segment  were
then  identified.   This  included  an  analysis  of  (1)  the
source flow and volume of water used in the process employed
and the sources of waste and waste waters in the plant;  and
 (2)  the  constituents   (including  thermal)  of  all  waste
waters, including toxic constituents and other  constituents
which  result  in  taste,  odor,  and  color in the water or
unfavorable   influence   on   aquatic    organisms.     The
constituents  of the waste waters which should be subject to
effluent limitations guidelines and standards of performance
were identified.

The range of control  and  treatment  technologies  existing
within  each  segment  was  identified.   This  included  an
identification  of  each  distinct  control  and   treatment
technology,   including   both  inplant  and  end-of-process
technologies,  which  are  existent  or  capable  of   being
designed   for   each   segment.    It   also   included  an
identification  in  terms  of  the  amount  of  constituents
 (including  thermal)  and  the effluent level resulting from
the  application  of  each  of  the  treatment  and  control
technologies.   The problems, limitations and reliability of
                          10

-------
each were also identified.  In addition, the nonwater impact
of  these  technologies  upon  other   pollution   problems,
including  airf  solid  waste, noise and radiation were also
identified.  The energy requirements  of  each  control  and
treatment  technology  was identified as well as the cost of
the application of such technologies.

The information, as outlined above, was  then  evaluated  in
order to determine what levels of technology constituted the
"best  practicable  control technology currently available",
the  "best  available   demonstrated   control   technology,
processes,  operating  methods,  or other alternatives".  In
identifying  such   technologies,   various   factors   were
considered.  These included the total cost of application of
technology in relation to the effluent reduction benefits to
be  achieved from such application, the age of equipment and
facilities involved, the process employed,  the  engineering
aspects  of  the  application  of  various  types of control
techniques, process changes, nonwater quality  environmental
impact  (including energy requirements), and other factors.

Delineation of Study

The  industry  is characterized by a relatively small number
of plants.  Only 1 plant exists  for  the  sodium  phosphate
subcategory.   Some of the plants did not cooperate with the
study because of trade  secret  factors.   Fortunately,  the
technology  developed  for the phosphorus derived segment of
phosphate manufacturing, and for the  phosphate  subcategory
of  fertilizer  manufacturing  is  extremely well suited for
handling the waste water problems of  this  segment  of  the
industry.   The  background  technology  has  been  utilized
extensively in establishing standards for the industry.

The effluent limitations guidelines and  standards  of  per-
formance   proposed  in  this  report  were  developed  from
operating data, sampling, and information  gathered  from  6
plants.  The methods and procedures used in the accumulation
of that data is described in the following paragraphs.

Identification and categorization of the 3 processes covered
in this report were made during the preparation of the Phase
I  portion  of  the  industry  report  on Phosphorus Derived
Chemicals.  These are:

          Defluorinated Phosphate Rock  (Subpart D)

          Defluorinated Phosphoric Acid (Subpart E)

          Sodium Phosphates (Subpart F)
                        11

-------
            (produced from wet process phosphoric acid)

Basis for Definition of Technology Levels

The validated data and 'samples described  in  the  foregoing
pages  were  the  primary  basis  for choosing the levels of
technology which were considered to be the "best practicable
control technology currently available", the "best available
technology economically achievable", and the "best available
demonstrated control technology, process operating  methods,
or  other  alternatives".   This  selection  of the separate
technologies,  of necessity, required consideration  of  such
additional  factors  as  evaluation  of  the engineering and
operational problems associated with the technology,  effect
on  existing  processes,  total  cost  of  the technology in
relation to the effluent reduction that would  be  realized,
energy   requirements   and   cost,  the  range  of  control
variations on contaminant concentration and/or quantity, and
non-water   quality   environmental   impact.    Information
regarding   the  influence  of  these  diverse  factors  was
obtained from a number of sources.   These  sources  include
government research information, published literature, trade
organization  publications.  United  States process patents,
and qualified consultants.   Final  levels  were  set  after
extensive discussions between legal and technical divisions.

Implementation

The value of a study such as this is entirely dependent upon
the  quality  of the data from which it is made.  Particular
attention was, therefore, directed to selecting criteria for
determining the commercial installations to be  visited  and
from which to collect information.

In this Phase II phosphate study the selection of individual
plants for participation in the survey required a minimum of
consideration after the initial U. S. industry plant identi-
fication.   Two  of  the  three processes had less than five
total U. S. operating plants.  The third process represented
a slightly larger number of operating  plants,  eleven,  and
was  found  to have essentially identical water usage, water
management and effluent treatment characteristics as one  of
the Phase I Phosphate Fertilizer Industry processes.

Because of the relatively few plants involved in each of the
Phase  II  processes,  the  consideration of exemplary plant
selection for the survey was not used.  For one process, all
U. S. plants were included.  For another, all except one  U.
S.  plant  were  included.  For the third process, its close
relationship to a similar Phase I process necessitated  that
                        12

-------
only  two  plants  representing  each  of  the two different
process variations in industrial  use  be  included  in  the
survey.  Full consideration of exemplary plants has now been
covered in cost studies.

Contact  was  then  made with each of the plants selected in
the separate processes to establish a time for  a  screening
visit.   The  screening visit had the objective of informing
the plant manager on the purpose and intent  of  the  study.
Information  acquired during the visit was used to determine
whether that particular plant was  to  be  included  in  the
study  or  whether  other  plants  and/or  conditions better
exemplified industry standards.  The plants included in  the
survey  were found to have good effluent monitoring programs
in effect and were maintaining comprehensive records.  Study
covered the important fluoride, suspended solids, phosphate,
radium 226, and pH parameters.   In  some  cases  the  plant
records  did  not  necessarily isolate the liquid streams to
and from the specific process unit involved  in  the  survey
but  did  provide  valuable  information on water management
control.

A comparative evaluation was  made  of  the  various  plants
visited.   This  evaluation was based upon the criteria used
in the Phase I study.  Tt consisted of the following points:

1.  Discharge Effluent Quantities

    Installations with  low  effluent  quantities  including
    some plants operating with no discharge of process waste
    water.

2.  Effluent Contaminant Level

    Installations  with  low  effluent  contaminant  concen-
    trations and quantities.

3.  Effluent Treatment Method and Effectiveness

    Installations  utilizing  the  best  currently available
    treatment methods, and control equipment.

H.  Water Management Practice

    Installations  with  utilization  of   good   management
    practices  such  as  main  water  re-use,  planning  for
    seasonal rainfall variations, in-plant water segregation
    and proximity of cooling towers to operating units where
    airborne contamination can occur.
                        13

-------
5.  Land Utilization

    Consideration of  land  area  involved  in  waste  water
    effluent  control  system with the most acceptable being
    those with the least area.

6.  Air Pollution Control

    Consideration  given  to  those  plants  with  the  most
    comprehensive  and  effective air pollution control.  In
    turn liquid effluent from such plants may represent  the
    most  serious waste water effluent condition.  Major air
    pollution  problems  considered  were  fluorine,  sulfur
    dioxide and radon 222.

7.  Geographic Location

    Consideration   given   to  those  facilities  in  close
    proximity  to  sensitive  vegetation,  and   with   high
    population  density.   Land  availability  and local and
    state restrictions and standards were  considered.   The
    greatest   attention   was   directed  to  rainfall  and
    evaporation conditions in the area.

8.  Management Operating Philosophy

    Plants whose management insists upon effective equipment
    maintenance and housekeeping practices.

9.  Diversity of Processes

    On  the  basis  that  other  criteria  are   met,   then
    consideration   was  given  to  installations  having  a
    multiplicity of processes.

Each above criterion  was  assigned  a  range  of  numerical
values  to  allow  a comparative evaluation of the different
plants visited in each process category.

Sampling Collection and Validation of Data

The most important item in a study  of  this  nature  is  to
obtain  data  representative  of  a  given process under all
conditions of  operation  and  range  of  production  rates.
Steps   and   procedures  used  in  selecting  data,  stream
sampling,  and  sample  analysis  were   all   designed   to
accomplish this goal to the best possible degree.

An  important  step toward this objective was the assignment
of only highly experienced operating personnel to the  field
                          14

-------
work.  Three persons were used.  The fertilizer plant opera-
ting  experience of these three people ranged from a minimum
of 16 years to 24 years.  With such operational knowledge it
was possible to expeditiously select data, identify specific
process streams for sampling,  and  conduct  sampling  under
readily  discernible plant operating conditions.  The points
considered and identified in all data collection,  sampling,
and validation were:

    1.  Segregation of process effluent streams so that only
    an identifiable single process and/or piece of equipment
    was represented.

    2.   Collection  of data and samples at different states
    of process conditions such as normal steady state, plant
    washout when such a procedure is followed on  a  routine
    basis, upset process condition, operation at above/below
    plant  design  rate,  and  during shutdown conditions if
    effluent flow occurs.

    3.  Evaluation  of  the  effect,  if  any,  of  seasonal
    rainfall,  particularly on non-point source effluent and
    ponds.

    4.  Establishment of the existence of  flow  measurement
    devices  and/or  other means of quantitatively measuring
    effluent flows.

    5.  Making positive identity of the type, frequency, and
    handling of the samples represented by collected data
    i.e., such items as grab, composite, or continuous type;
    shift, daily or weekly frequency, etc.  All samples col-
    lected by the contractor were composite samples.

    6.   Validation  of  data through determination of plant
    laboratory  analytical  procedures   used   for   sample
    analysis,   check   samples   analyzed   by  independent
    laboratories,  and/or  DPG  sampling  under  known   and
    defined  process  conditions  with sample analysis by an
    accredited commercial laboratory, was completed at  each
    plant.   A  total of 6 plants were visited and data were
    collected at each plant.

GENERAL DESCRIPTION OF THE INDUSTRY

The segment of the U.S. phosphate industry included in  this
Phase  II  survey includes phosphate manufacturing processes
which utilize phosphate rock or wet process phosphoric  acid
as  basic  raw  materials.   Phosphate products manufactured
from  these  processes   are   utilized   as   animal   feed
                          15

-------
ingredients,  fertilizer  intermediates,  and  high  quality
sodium phosphate salts.

One of the phosphate  processes  is  the  defluorination  of
phosphate  rock.   During  the  early stages of World War II
bone meal for use as an animal  feed  supplement  came  into
short  supply.  This short supply situation spurred activity
for finding an alternate source and/or  process  to  satisfy
this  material  so  important  to  the  production of animal
foodstuffs.  Bone meal supplies two important animal mineral
requirements,  namely  calcium  and  phosphorus.   Lack   of
adequate  levels  of  these  ingredients  can result in such
animal disorders as aphosphorosis, rickets or infertility.

Materials which can furnish  these  calcium  and  phosphorus
ingredients  can  be  derived from two general sources.  The
natural occurring type materials used for these minerals are-
such items as bonemeal, meatmeal and fishmeal.  An alternate
source was through processing phosphate rock.   The  problem
with  phosphate  rock  as a direct source lay in the need to
reduce the 3 to 4 percent fluorine content in the rock to  a
level which was not harmful to animals upon ingestion.

The  outcome  of  this animal feed supplement supply problem
was  that  three  methods  were  developed  and   put   into
commercial  operation.   Over  the  past  years  process and
equipment improvements have gradually proven one process  to
have  the better overall commercial values.  This process is
described in detail on the following pages of  this  section
and  is the process used at the three plants included in the
survey.

The  estimated  annual  U.S.  production  of   defluorinated
phosphate rock for recent years is indicated below.

                  Estimated Annual U.S. Production
                         Thousands of kkg (tons)
                         Defluorinated Rock
                            18% P Content

1968     1969     1970      1971    1972     1973       1974

373(410) 394(435) 380(430) 394(435) 444(490) 485(535) 485(535)

Plant site locations for U.S. plants are indicated on Figure
III-l.

A  second  phosphate  process  included  in the study is the
defluorination  of  wet  process  phosphoric   acid.    Acid
defluorination  is accomplished commercially by two methods.
                           16

-------
DEFLUORINATED PHOSPHATE ROCK
        PLANT  LOCATIONS
                                                 FIGURE III-l

-------
                                     DEFLUORINATED PHOSPHORIC ACID
co
                                            PLANT LOCATIONS
                                                                                    FIGURE III-2

-------
SODIUM PHOSPHATES
PLANT LOCATIONS
                                        FIGURE III-3

-------
The  method  in  most  common  use  is  the  manufacture  of
superphosphoric acid.  This process essentially involves the
concentration   of   phosphoric  acid  from  a  52-54%  P2O5
concentration level to a 68-72% P_2°.5 level.  In the  process
of  evaporating  water  from  the  acid,  fluorine  is  also
removed.  The degree of fluorine removal is  dependent  upon
the  initial  fluorine  level  and the final phosphoric acid
concentration.   In  most  cases  the  fluorine  removal  is
sufficient to permit use of the concentrated phosphoric acid
for manufacture of animal feed supplements.

Two types of phosphoric acid evaporators are used to produce
superphosphoric  acid.   One type uses the principle of acid
circulation  in  a  vessel  maintained  at   sub-atmospheric
pressure.   This  is  the  type most prominent in the United
States.  A second type uses the principle commonly  referred
to as submerged combustion.  In this type hot gases directly
from a fuel fired combustion chamber are bubbled through the
acid.

The  second  method of acid defluorination in commercial use
is the combination of the addition of  an  additive  to  the
acid which in turn facilitates fluorine removal by aeration.

Defluorinated acid has several end uses.  A large percentage
of the defluorinated acid is mixed with limestone to produce
dicalcium   phosphate   for   animal  feed  supplement  use.
Increasingly greater quantities are being  used  for  liquid
fertilizer  production.  This use, however, does not require
low fluorine content acid.  There is also an increasing  use
of superphosphoric acid as an intermediate in the production
of dry mixed fertilizer.  The advantage in this latter usage
is  a  combination  of  reducing fluorine evolution from the
manufacturing process and savings on  raw  material  freight
costs.

The   current   annual   U.S.  production  of  defluorinated
phosphoric acid is estimated at 760,000 kkg   (835,000  tons)
P2O5_.   Plant  site locations for U.S.  plants are indicated
on Figure III-2.

The third phosphate process included in the  survey  is  the
production   of   high   quality   sodium  phosphate  salts.
Conventionally, high purity phosphoric acid as produced from
thermal or electric furnace operations is used  as  the  raw
material  for  such compounds.  Wet process acid is however,
used by one U.S. manufacturer  to  produce  these  compounds
primarily  for  use  as  intermediates  in the production of
cleaning compounds.  The plant site location  map  for  this
type unit is indicated as Figure III-3.
                           20

-------
                         SECTION IV

                 INDUSTRY SUBCATEGORIZATION

The  subcategorization  developed  for  this  segment of the
phosphate industry was largely determined in the  course  of
the  Phase  I  phosphate  study  and  the Phase I fertilizer
phosphate study.  Phosphoric acid derived from phosphorus is
a much purer product  than  the  wet  process  acid  of  the
fertilizer  industry.   Human food grade calcium phosphates,
most reagent chemical quality phosphate compounds and sodium
tripolyphosphate are made from phosphorus derived acid.

A  comparative  list  of   the   impurities   and   physical
characteristics  of  furnace  acid  and wet process acid are
indicated in the following table.

     Impurities          Furnace Acid      Wet Process Acid

                         	Weight Percent

      F
     S03i
     A120 3
O.C07
0.003
0.001
0.0007
-
0.6-1
2.7
0.9
1.2
0.8
.0




     Water Insolubles

     Total Impurities         0.012           6.2 - 6.6

     Density kg/1 (Ib/gal)    1.57 (13.1)        1.72  (14.3)
     3) 27°C (80°F)

     Viscosity, cp            18                85

     Color                   Colorless       Pale green to
                                              dark brown

Although the phosphate compounds of highest purity  require-
ments  are  made from phosphorus derived acid, a substantial
demand developed for products of adequate quality  for  many
uses,  but  cheaper than the furnace acid derived materials.
Ma-jor products in  this  area  are  calcium  phosphates  for
animal   feed,  defluorinated  phosphoric  acid  and  sodium
phosphates.   The  industry  supplied  this  demand  through
defluorination  of  phosphate  rock,   and  defluorination of
phosphoric acid.  The sodium phosphate demand is supplied by
products  derived  from  the  purification  of  wet  process
phosphoric acid, derived from calcined rock.

-------
Within  this  group  of  chemicals,  the  defluorination  of
phosphate rock  is  carried  out  by  dry  calcining,  which
distinguishes it sharply from the remaining products derived
through  defluorinating  liquid  phosphoric  acid.  The most
favorable water balance within the segment is held  by  this
defluorinated  rock  process.   Substantial evaporation loss
occurs in stack washing to control fluoride  emission.   The
water  used  for stack washing picks up substantial fluorine
pollution,  much  the  same  as  the  scrubber   water   for
fertilizer  phosphate plant acid.  The major problem is best
handled by recirculation through a contaminated  water  pond
type of recycle system.

Water  is  collected  from  the defluorination of phosphoric
acid.  This is water driven from the acid by heat, aided  by
air streams and/or vacuum.  This water contains the fluoride
contaminant  common  to  phosphoric  acid  production.   The
defluorination processes  in  use  are  accompained  by  the
formation  of dehydrated and polymer forms of phosphate from
the orthophosphate in rock and in wet process  acid.   These
phosphate  varieties have high calcium salt solubility; this
introduces  a  treatment  problem  lacking   in   fertilizer
phosphate  production  if the defluorinatied products get to
the waste water.

Sodium phosphates are produced from conventional wet process
phosphoric acid, which has been derived from calcined  rock.
The  cacining  improves product color through destruction of
organic components.  The production of sodium phosphates  is
associated   with   waste  water  problems  similar  to  the
fertilizer phosphate problems.  The conversion  of  rock  to
phosphoric   acid  is  by  the  usual  fertilizer  phosphate
process.  The purification steps conducted in phosphate salt
manufacture required the  blowdown  of  process  water  with
fluorine,  sulphate and phosphate waste water components, as
well as other salts and solids.

Conventional wet acid production is  carried  out  prior  to
production of both defluorinated acids and the sodium salts.
These plants have typical wet acid problems.  As a result of
these considerations, and factors developed in the following
sections   on   manufacturing  technology  and  waste  water
characteristics, 3 subcategories have been  established  for
this segment of phosphate manufacturing:

    Subpart D - The Defluorinated Phosphate Rock Subcategory

    Subpart   E   -   The   Defluorinated   Phosphoric  Acid
              Subcategory

    Subpart F - The Sodium Phosphates Subcategory.
                          22

-------
                         SECTION V

                   WASTE CHARACTERIZATION
The technical aspects of  the  manufacturing  processes  are
described  in  this  section,  along  with identification of
water usage, and the development of waste water flow.

DEFLUORINATED PHOSPHATE ROCK - PROCESS DESCRIPTION

General

As mentioned earlier in Section III, the early World War  II
shortage  of  bonemeal  produced  the necessary incentive to
find an alternate source of animal feed supplement.  The two
ingredients required were calcium and phosphorus  and  these
two  elements  were  prominently  present  in  apatite  type
phosphate rock.  The one  natural  apatite  rock  ingredient
which  prevented  its use as an animal feed material was the
relatively high  (3.0 - U.0%)  fluorine  content.   Basically
the   problem   was   to   find   an   economical  means  of
defluorinating the rock and still have an end product  which
would  be  palatably  acceptable to primarily cows, chickens
and  pigs.   Three  general  methods   were   developed   to
defluorinate the phosphate rock.

One  method  involved  treatment  of  normal superphosphate-
produced  by  mixing  phosphate  rock  with  sulfuric  acid.
Reaction  of  the  phosphate  rock  and  sulfuric breaks the
chemical bond that holds the fluorine  in  the  fluorapatite
lattice.    This   superphosphate   is   then  subjected  to
temperatures which volatize essentially  all  the  fluorine.
The  mono  and dicalcium phosphate compounds in the material
are converted to alpha and beta tricalcium phosphate  during
the heat treatment.

A  second  method  involves treating a prescribed mixture of
phosphate rock and silica in an  oil  fired  shaft  furnace.
This   also  volatizes  the  fluorine  and  yields  a  fused
tricalcium phosphate mass.  The  hot  mass  is  quenched  in
water  immediately  upon  exit  from  the furnace.  Chemical
composition of the product is approximately  28%  phosphorus
pentoxide and O.U% fluorine.

The   third  method  is  described  as  the  calcination  of
phosphate rock without fusion.  It has demonstrated the most
favorable commercial characteristics and has become the most
prominent U.S.  defluorination  process.   There  have  been
several  significant modifications to this process since its
                           23

-------
                   DEFLUORINATED PHOSPHATE ROCK
                         FLUID BED PROCESS
Fluidizing Gas
                                                                        > Atmosphere

                                                                         Contaminated
                                                  Recycle
Agglomerated and
Defluorinated
Phosphate
Product
Contaminated
Water to
Retention
      Pond
         45,894 1/kkg
         11,000 g/s.t.
                                                                      Figure  V-I

-------
initial commercial operation in 1944.  Initially the process
utilized a mixture of phosphate rock and silica  as  a  feed
material.   The  silica  used  was sand that is a by-product
from phosphate  rock  beneficiation.   Ratio  of  silica  to
phosphate rock was an important criterium in the defluorina-
tion  process.  This charge of silica and phosphate was then
introduced to a rotary kiln.  In the interim years these two
original steps - use of silica ratio and rotary kiln -  have
been  modified.   Silica  has  been  partially replaced with
sodium compounds and the rotary kiln has been replaced by  a
fluid  bed  reactor.   Not all U.S. production units utilize
both of these modifications but both are  practiced  by  the
major producers.  A more detailed process description of the
process  using  both these modifications is presented on the
following pages.

The defluorination of phosphate rock as  practiced  at  U.S.
commercial  production plants is a process on which there is
a limited amount of published information available.   Plant
visits  included  only  guarded  technical  discussions  and
limited plant observations.  One of the primary reasons  for
these   practices   is   the   protection  of  trade  secret
information.  U.S. patents were therefore the  major  source
of process information.

The  fluorapatite  type of phosphate rock is the primary raw
material.  Phosphate content of the rock  is  typically  35%
P2O5.   Other  raw materials used in lesser amounts but very
critical to the process include sodium containing  reagents,
wet process phosphoric acid and silica.  The quantity, point
of  addition of these materials to the process, and how they
are mixed with the phosphate rock  constitute  some  of  the
know-how  involved  to  realize  a  workable  process  and a
consistent product quality.  These raw materials  are  added
in  specific  quantities  or  ratios dependent upon the feed
phosphate rock analysis.

The sodium containing reagent is commonly soda  ash   (sodium
carbonate)   which has a Na_20 content of approximately 58% or
over  98%  Na^CO3.   The   wet   phosphoric   acid   reagent
concentration  used  is  45-54% P.2Oj>.  Silica addition is in
the form of sand and is dependent on the silica  present  in
the  basic phosphate rock feed.  As previously mentioned the
point of addition and how these materials are mixed together
either as a physical mixture or  agglomerated  into  nodular
form  is  one  of  the  trade  secrets.  The above described
mixture or charge is then fed into either a rotary kiln or a
fluid bed reactor.  In the case of a fluid bed  reactor,  it
is  desirable  that the charge be nodular and dried prior to
beinct fed into the reactor.  This is in consideration of the
                         25

-------
fluid   bed   characteristics    of    effecting    particle
classification  and loss in the exhaust gas.   In the kiln or
fluid bed reactor,  temperature control  and  retention  time
are  the  process  variables  which  require   close control.
Reaction temperatures are maintained in the  1205  -  1366°C
(2200- 270 0°F)  range with the rotary kiln requiring the upper
portion of the range.

Retention  time  ranges from 30 to 90 minutes with the fluid
bed reactor generally requiring the lesser time.

The state of the charge in the kiln or fluid  bed reactor  is
highly  dependent  upon the ratio of the raw  materials added
to the phosphate rock.  That is,  whether  the  fluorine  is
evolved  in  a minimal time period or in sufficient quantity
and/or whether the charge fuses into  an  unmanageable  mass
that  rings  or  solidifies  in  the unit. Another critical
factor in  these  units  is  that  water  vapor  content  be
maintained  at  a sufficiently high percentage to effect the
required fluorine evolution.  The equation representative of
the chemical reaction and fluorine release in the kilns  and
fluid bed reactors cited in preceding text is:
   Ca.lOF2 (PO4)€i * Hl° * SiO2!  =  3Ca3(PO4)2  + CaSiO2 + 2HF
phosphate rock  water  silica  tricalcium  calcium   hydrogen
                               phosphate   silicate  fluoride

The  reaction  is  actually much more complex.  Dehydration,
not hydrolysis, occurs in the kiln.  The product  phosphates
are primarily in the poly or dehydrated form.  Hydrolysis of
silicon  fluoride  to silica and hydrofluoric acid occurs on
water scrubbing of the tail gas.

From the kiln or fluid bed reactor the defluorinated product
is quickly quenched with air or water.  This is necessary to
maintain  the  product  in  the  alpha  rather   than   beta
tricalcium  phosphate  form.   The  alpha  form  is the high
solubility material most desirable  in  the  final  product.
From this point the product is crushed and sized for storaae
or shipment.
Defluorinated Phosphate Rock - Waste Water Characterization

As  previously  mentioned, the detail and amount of specific
information  on  water  usage  and  effluents  received  and
verified in this survey was minimal.  There were two general
reasons for this situation.  One was that none of the plants
had  operable  flow  metering equipment.  A second reason is
the point already mentioned - that  of  reluctance  to  give
                          26

-------
technical  data  and free access to the plant operating area
due to the many items regarded as  trade  secrets.   From  a
practical  standpoint  such  information  in this case would
serve only as background data and a better understanding  of
the overall process water balance.  On those items which are
important  to  the study such as water management practices,
effluent analyses, and permission  to  conduct  sampling  of
inlet  and  outlet  effluents  there  was excellent industry
cooperation and information input.

The following  types  of  water  usage  and  effluents  were
identified.

    A.   Contaminated  Process  Waste   Water   from   Stack
         Scrubbing and Reuse Pond

    B.  Water Supply

    C.  Spills and Leaks

    D.  Non-Point Source Discharges

Each  of the above listed items are further identified below
as to flow and contaminant content  under  their  respective
headings.

    A.  C ontaminated Process Waste Water from Stack
         Scrubbing (Recycle and Reuse Pond)
         The  greatest  single  process wastewater source is
         from water used in scrubbing contaminants from  the
         gaseous    effluent    streams.     This   has   an
         instantaneous water requirement is  of  appreciable
         magnitude  and  process conditions do permit use of
         recirculated contaminated water for  this  service.
         The  quality  of this contaminated water is similar
         to that in fertilizer process circulation  systems.
         The waste water volume is not normally dependent on
         the  rainfall  and evaporation conditions prevalent
         at the plant site.  Most  plants  are  on  complete
         recycle.   Evaporation  losses  are  so  great that
         excessive  wastewater  accumulations  will  require
         treatment   and   discharge   only  in  periods  of
         excessive rainfall.

         Complete recycle does not eliminate  the  need  for
         lime  trestment.   Hydrofluoric  acid  is  released
         constantly  in  the  high   temperature   calcining
         process,  along  with  sulfurous and sulfuric acids
         derived from fuel.  Each plant must  take  measures
                        27

-------
         to  control  the  accumulation  of  acid to prevent
         excessive air pollution.   Air pollution control  is
         achieved   by  adding  lime  to  the  recirculating
         wastewater at the stack,  adding lime to  the  pond,
         or   by   constantly   liming   a  portion  of  the
         recirculating  pond  water,  removing  the  calcium
         fluoride,  the  calcium  sulfate  and  the  calcium
         phosphate   precipitates,   and    returning    the
         supernatant fraction to the pond.  Solid wastes are
         always  formed by the measures essential to control
         air pollution.  The wastewater composition  may  be
         unusual  at  sites  where  manufacture  of products
         other than defluorinated rock is  carried  out  and
         the  wastewater from these products discharged into
         the recycle and cooling  pond.   system.   A  water
         analysis  obtained from a Plant B sample during the
         survey is typical of  contaminated  water  used  in
         defluorinated phosphate rock process units.

         Contaminated Water Constituents

         Parameter                       Cone entr at i on

         pH                                  1.65
         Total Suspended Solids             16.00 mg/1
         Total Solids                    2,267.00 mg/1
         CMoride (Cl)                      101.00 mg/1
         Sulfate  (SO4)                      350.00 mg/1
         Calcium  (Ca)                        UO.OO mg/1
         Magnesium (Mg)                     12.00 mg/1
         Aluminum (Al)                       58.00 mg/1
         Iron (Fe)                           8.30 mg/1
         Fluorine (F)                     1,930.00 mg/1
         Arsenic  (As)                         0.38 mg/1
         Zinc (Zn)                           5.20 mg/1
         Phosphorus (P)                   600.00 mg/1
         BOD5                                3.00 mg/1
         COD                                48.00 mg/1
         Color                            #120  (after filter)
         Turbidity                          15.00 Jackson
                                               Candle Units

The following figures indicate a representative water usage.
These  figures  will  vary  within reasonable limits between
plants  and  at  different  seasons  of  the  year  but  are
representative  of  the  magnitude  of usage required in the
process.

                 1/kkg                      (gal/ton)
                         28

-------
             45,894                       (11,000)

B.   Water Supply

     Water  supply  water  is  defined  as   essentially
     uncontaminated  water  from  such sources as wells,
     commercial  or   municipal   water   systems,   and
     impoundment  areas  for natural rainfall or runoff.
     Such water is added to the process for such reasons
     as process functions where contaminated  water  use
     is  prohibited due to process requirements, make-up
     water  to  the  contaminated   water   system   and
     equipment,  or  area  wash  downs.   The  following
     figures indicate the usage range.

             1/kkq                      (gal/ton)

              877                         (210)


C.  Leaks and Spills

     Various sources of contaminated non-process  waste-
     water  have  been  established by the definition of
     "contaminated non-process wastewater" that  appears
     in  the  regulations  pertaining  to  defluorinated
     phosphate rock manufacture:
     The  term  "contaminated  non-process   wastewater"
     shall   mean   any  water  including  precipitation
     runoff, which during manufacturing  or  processing,
     comes   into   incidental   contact  with  any  raw
     material, intermediate product,  finished  product,
     by-product   or  waste  product  by  means  of  (1)
     precipitation runoff, (2)  accidental  spills,  (3)
     accidental  leaks  caused by the failure of process
     equipment and which are repaired or  the  discharge
     of  pollutants  therefrom  contained  or terminated
     within the shortest reasonable time which shall not
     exceed 24 hours after discovery or  when  discovery
     should  reasonably  have  been  made,  whichever is
     earliest, and (4) discharges  from  safety  showers
     and  related  personal  safety  equipment, and from
     equipment washings for the purpose of  safe  entry,
     inspection   and  maintenance;  provided  that  all
     reasonable measures have  been  taken  to  prevent,
     reduce, eliminate and control to the maximum extent
     feasible such contact and provided further that all
     reasonable  measures  have  been  taken  that  will
     mitigate the effects of such contact  once  it  has
     occurred.
                      29

-------
         While  an allowance has been made for the discharge
         of treated contaminated non-process wastewater,   it
         is  the  responsibility  of  every  manufacturer to
         exercise  diligence  in  repairing  leaks   or   in
         correcting    other    conditions    that    create
         contaminated  non-process   wastewater,    so   that
         contamination is held to the lowest possible level.

         Many  manufacturers have demonstrated that spurious
         contamination  from  leaks  and  spills   and  other
         sources   can   be   kept  at  a  very  low  level.
         Continuous analysis of pH,  conductivity  or  total
         organic  carbon is being conducted on large cooling
         water streams so  that  serious  leaks  are  almost
         immediately  detected.  Corrective measures are put
         into action  immediately  on  detection.   In  many
         circumstances,  the  system  salvages products  of
         sufficient  value  to  more  than   pay    for   the
         monitoring  system.   Good  housekeeping practices,
         efficient operation  and  prompt  maintenance  will
         minimize  contamination  of  water  from  leaks and
         spills.   Techniques  for  achieving  control   and
         prevention   of   such   losses  are  described  in
         "Guidelines for Chemical Plants in the  Prevention,
         Control   and   Reporting   of   Spills"   by   the
         Manufacturing Chemists Association, 1972.

         Shipping losses were excluded from  the   data  base
         and regulations.  These losses are egually amenable
         to  control  and  prevention  as  leaks  and spills.
         Good housekeeping, prompt and regular maintenance,
         and careful operations will tend to minimize losses
         from shipping operations.

    D.  Non-Point Source Discharge

         The  origin  of  this  discharge is dry  materials -
         both raw material and product - which dust over the
         plant   area   usually   emitted   from    conveying
         equipment.   These  materials are then solubized or
         sluiced by rain or  melting  snow  into   the  plant
         drainage system.

    DEFLUORINATED PHOSPHORIC ACID - PROCESS DESCRIPTION

General

Defluorinated   phosphoric   acid  is  to  a  degree  a  bit
misleading  to  persons  associated  with   the   fertilizer
industry.   The  reason  being  that  acid defluorination is
                         30

-------
inherently included in the process of evaporating commercial
wet process 54% P2O5 phosphoric acid to the  superphosphoric
acid  (68-72%  P2Oj>)  concentration  level.   To  fertilizer
people therefore, the principal  U.  S.  defluorinated  acid
process is better known as a superphosphoric acid unit.  Two
different  type  superphosphoric units are in commercial use
in the U. S.

Another method of defluorinating wet process phosphoric acid
has come into commercial use in the past  few  years.   This
process also uses commercial wet process 54% P2Oj> phosphoric
acid  as  the  raw material.  In this process an additive is
mixed with the phosphoric acid to aid  in  the  release  and
volatilization  of  fluorine from the liquid.  The mechanism
for fluorine removal from the acid is aeration.

Defluorinated phosphoric acid is used  primarily  as  a  raw
material for production of mixed fertilizer goods - both dry
and  liquid  types.   It is also mixed with limestone in the
manufacture of dicalcium phosphate for use as an animal feed
supplement.   Approximately  67%  of  the  estimated  U.  S.
835, ^00  annual  tons P2Oj> quantity of def luorinated acid is
used in fertilizer manufacture and 33% in the production  of
dicalcium  phosphate.  The degree of defluorination required
to meet animal feed regulations is that the P to F ratio  be
at least 100 to 1.
         DEFLUORINATED ACID - VACUUM TYPE EVAPORATION

The vacuum type evaporation method for defluorination of wet
process  phosphoric  acid  is  essentially  identical to the
procedure and equipment used to produce 54% P2O5  phosphoric
acid from 26-30% P2O5 strength acid.

Concentration  of 54% P2O5 acid to a 68-72% P2O5 strength is
performed in vessels which use high pressure  (450-55C  psig)
steam  or  externally  heated  Dowtherm solution as the heat
energy source for evaporation of water from the acid.  These
units effect evaporation  by  circulating  acid  at  a  high
volume  rate  consecutively  through  a  shell and tube heat
exchanger and a flash chamber under  low  absolute   (vacuum)
pressure  conditions.   In  the  heat  exchanger,  steam  or
Dowtherm solution is applied to  the  shell  side  and  acid
flows  through tubes.  Acid flow through the tubes is of the
wetted wall type rather than  full  tube  flow.   The  flash
chamber  serves to provide a large liquid surface area where
water vapor is released without significant acid entrainment
loss.  Fluorine removal from the  acid  occurs  concurrently
with the water vapor release.  Both of these gases pass to  a
                       31

-------
barometric  condenser  and  are  absorbed  in  the condenser
water.  Dependent upon the quality of  superphosphoric  acid
being   produced   (e.a.   30   or   50-6055   conversion  to
polyphosphates), either a single unit or  a  series  of  two
units  may  be  used  to  accomplish  the evaporation and/or
defluorination required.
         DEFLUORINATED ACID - SUBMERGED COMBUSTION

A second method of phosphoric acid defluorination is by  the
direct  contact  of  hot combustion gases with the acid.  In
this method a combustion chamber fitted  with  one  or  more
fuel  oil  or  gas  burners is mounted directly on top of an
acid containment chamber.  Pressurized hot  gases  from  the
fuel combustion are bubbled through the acid to an immersion
depth of up to approximately 46 cm (18 inches).   Acid in the
containment  chamber  is  maintained  at a constant level by
control of  the  low  concentration  feed  acid  flow.   The
production of evaporated and defluorinated product acid from
the  unit  is  continuous  and is controlled by acid boiling
point or temperature.
      (evaporated  water,  stripped  hydrogen  fluoride  and
silcon tetrafluoride)  from the evaporation chamber flow to a
series  of  gas  cleaning  and absorption equipment.  First,
entrained phosphoric acid is recovered from the  gas  stream
and  re-introduced  to  the  unit  or to the phosphoric acid
plant.  Following acid removal, the gases pass to  a  multi-
stage   direct   contact   condenser  system  where  a  high
percentage of the contaminants are removed before exhaust to
the atmosphere.  Water can be used in all or only the  final
stages of the condenser system as a condensing and scrubbing
medium.
         DELUORINATED ACID - AERATION

This  method  of  defluorinating phosphoric acid is the most
recent proprietary  method  to  come  into  commercial  use.
Relatively  small quantities of diatomaceous silica or spray
dried silica gel with high surface area characteristics  are
mixed with commercial 54% V2O5 phosphoric acid.  This silica
material  addition  serves  to  supply sufficient silica for
conversion of the minor quantity of hydrogen  fluoride  (HF)
present  in  the  impure phosphoric acid to fluosilicic acid
(H2SiF6).  Fluosilicic acid at an  adequate  temperature  in
turn  breaks down to SiF4_ and by simple aeration is stripped
from the heated mixture.  The  gaseous  effluent  stream  is
maintained  above  its  dew  point  until  it enters the gas
                        32

-------
                       Water
     DEFLUORINATED PHOSPHORIC ACID - VACUUM PROCESS
                   (Super Phosphoric)

                             Water
         Water
         water	i	
         Steam	1  	  	
         	—— — "^^     T      P\
54% Phos-
phoric Acid
                                                             No. 2
                                                             Evapo-
                                                             rator
 Shipping
                Pump
Product
Cooler
                                              To Cooling Pond
                                               70,510 1/kkg
                                               16,900 g/s.t.
                                                                                Alternate Heat
                                                                                  Medium
                                                         "I
                                                        Alternate Heat Medium

                                                         i—... — i    Combustion
                                                             j         Gases

                                                           Fuel
                                                                                Process
                                                                                Water
                                                                                43 1/kkg
                                                                                14 g/s.t.
                                                                                         Figure  V-2

-------
                                  DEFLUORINATED PHOSPHORIC ACID
                                      (Submerged Combustion)
     Gas
Air
Feed Acid

	 >

Burner

i i
1 Dip Tube i
*v X
X s
v_ 	 /
\
1



r*.

_?>

^

Pond
Water
  18,024
  7    1/kkg
  4,320
      g/s.t.
                                                                            To Atmosphere
                                                                              t
 OJ
V
/


Evaporator
f
hosphoric
d



scruoce
•f\
-^


-------

Process
 Water
Silica
                                DEFLUORIN'ATED ACID - AERATION TYPE
                                                   Contaminated
                                                   Water   	
       54%
Phosphoric
             I
P205
Acid
                     Product to
                      Shipping
                                                     To
                                                  Atmosphere
                                                                      Scrubber
                                                                                     Fan
                                                                                  To
                                                                             Contaminated Water
                                                                                  Pond
                                                                      Steam
                                                             Heat
                                                             Exchanger
                                                             	^Condensate Return
                                                      Circulation Pump
                                                                            Figure  V - 4

-------
scrubbing unit.  At this point the gas stream  is  contacted
with  water  to  remove  contaminants  before release to the
atmosphere.  Phosphoric acid (5H% P2()5)  can be defluorinated
to a weight ratio of 100 to 1 or  better  P  to  F  by  this
method.

Defluorinated Phosphoric Acid - Waste Characterization

Information on water usage and effluents was obtained on two
of  the  three  defluorination  methods  described,  namely,
Defluorinated   Acid   -   Vacuum   Type   Evaporation   and
Defluorinated  Acid  -  Submerged Combustion.  No commercial
operating data or sampling information was obtained  on  the
Defluorinated  Acid  -  Aeration  method.   This  method  of
defluorination has been commercial for  a  relatively  short
time  and  patent protection had not yet been granted either
the original inventor or  the  licensee  on  his  additional
modifications.   As  a  result of this situation no detailed
information was attainable on this  process.   It  is  known
however,  that  the method's usage is confined to removal of
air  contaminants  from  the  gaseous  effluent  stream  and
possibly  a  minor  quantity of process water for seal water
use.   Both  of  these   usages   will   qualitatively   and
quantitatively  be equal to or less than those indicated for
the other two methods.

The following  types  of  water  usage  and  effluents  were
identified:

A.  Contaminated Process Waste Water from Tail Gas or
    Stack Scrubbing Operation  (Recycle and Reuse Pond)

B.  Water Supply

c-  Leaks and Spills

Various sources of contaminated non-process wastewater  have
been  established  by  the  definition of "contaminated non-
process  wastewater"  that  appears   in   the   regulations
pertaining to defluorinated phosphoric acid manufacture:
The  term  "contaminated  non-process wastewater" shall mean
any  water  including  precipitation  runoff,  which  during
manufacturing  or  processing, comes into incidental contact
with  any  raw  material,  intermediate  product,   finished
product,  by-product  or  waste  product  by  means  of  (1)
precipitation runoff, (2) accidental spills, (3)  accidental
leaks  caused  by the failure of process equipment and which
are  repaired  or  the  discharge  of  pollutants  therefrom
contained  or terminated within the shortest reasonable time
which shall not exceed 24  hours  after  discovery  or  when
                         36

-------
discovery  should  reasonably  have  been made, whichever is
earliest, and (4) discharges from safety showers and related
personal safety equipment, and from equipment  washings  for
the  purpose  of  safe  entry,  inspection  and maintenance;
provided that all reasonable measures  have  been  taken  to
prevent, reduce, eliminate and control to the maximum extent
feasible   such   contact  and  provided  further  that  all
reasonable measures have been taken that will  mitigate  the
effects of such contact once it has occurred.

While  an  allowance  has  been  made  for  the discharge of
treated  contaminated  non-process  wastewater,  it  is  the
responsibility  of  every manufacturer to exercise diligence
in repairing leaks or in correcting  other  conditions  that
create   contaminated   non-process   wastewater,   so  that
contamination is held to the lowest possible level.

Many   manufacturers   have   demonstrated   that   spurious
contamination from leaks and spills and other sources can be
kept  at  a  very  low  level.   Continuous  analysis of pw,
conductivity or total organic carbon is being  conducted  on
large cooling water streams so that serious leaks are almost
immediately  detected.   Corrective  measures  are  put into
action immediately on detection.  In many circumstances, the
system salvages products of sufficient value  to  more  than
pay for the monitoring system.  Good housekeeping practices,
efficient  operation  and  prompt  maintenance will minimize
contamination of water from leaks  and  spills.   Techniques
for  achieving  control  and  prevention  of such losses are
described  in  "Guidelines  for  Chemical  Plants   in   the
Prevention,   Control   and  Reporting  of  Spills"  by  the
Manufacturing Chemists Association, 1972.

Shipping  losses  were  excluded  from  the  data  base  and
regulations.   These  losses are equally amenable to control
and prevention as  leaks  and  spills.   Good  housekeeping,
prompt  and regular maintenance, and careful operations will
tend to minimize losses from shipping operations.

A.  Contaminated Water

    The only significant water usage in these  defluorinated
    acid  methods  is for use in scrubbing contaminants from
    the gas effluent streams.  The scrubber equipment may be
    in the form of either a barometric condenser or the more
    conventional gas scrubber type.   In  either  case,  the
    instantaneous   water   requirement  is  of  appreciable
    magnitude.  As in the defluorinated phosphate rock,  the
    process  conditions  do permit use of contaminated water
    for  this  service.   Water  quality  similar  to   that
                         37

-------
    prevailing   in  wet  process  phosphoric  acid  recycle
    systems.   A common recycle system is  utilized  at  some
    plants   for   wet   acid   and  for  deflurinated  acid
    production.  Wastewater volume is dependent on  rainfall
    and evaporation conditions at plant site.  The amount of
    acid collected in the wastewater at a defluorinated acid
    plant  is  determined by the amount of hydrofluoric acid
    removed from the raw product wet  phosphoric  acid,  and
    the   phosphoric   and   sulfuric  acids  entrained  and
    separated in the  fluoride  removal  process.    A  water
    analysis  obtained  from  a  Plant  D  sample  during the
    survey  is  typical  of  contaminated  water   used   in
    defluorinated acid process units.

               Contaminated Water Constituents
        Parameter                           Concentration

        pH                                       1.29
        Total Suspended Solids                  30.00 mg/1
        Total Solids                        28,810.00 mg/1
        Chloride (Cl)                            65.00 mg/1
        Sulfate (SOU)                         4,770.00 mg/1
        Calcium (Ca)                         1,700.00 mg/1
        Magnesium (Mg)                          106.00 mg/1
        Aluminum (Al)                           260.00 mg/1
        Iron (Fe)                               180.00 mg/1
        Fluorine (F)                           967.00 mg/1
        Arsenic (As)                             0. 83 mg/1
        Zinc (Zn)                                 5. 30 mg/1
        Total Phosphorus (P)                 5,590.00 mg/1
        BOD5                                    15.00 mg/1
        COD                                    306.00 mg/1
        Color                               #120 (after filter)*
        Turbidity                               45 Jackson
                                                  Candle Units

        *  Unit of color - potassium chloroplatinate
The following figures indicate a representative water usage.
These  figures  will  vary  within reasonable limits between
plants  and  at  different  seasons  of  the  year  but  are
representative of the magnitude reguired in the process.

     Method                   1/kkg           (gal/ton)

     Defluorinated Acid -     70,510            16,900
     Vacuum Type Evaporation
                         38

-------
     Defluorinated Acid -     18,024             4,320
     Submerged Combustion

B.   Water Supply

Water  supply  water is defined as uncontaminated water from
such sources as wells  and  commercial  or  municipal  water
systems.   The  water  is  used  for pump seal water.  Usage
figures are listed below:

     Method                   1/kkg           (gal/ton)

     All Methods               43               14

C.  Spills and Leaks

Spills and leaks are collected as part of process efficiency
and housekeeping.  Sources of this water are pump seals  and
plant wash up.  The quantity is minor and/or periodic.

         SODIUM PHOSPHATE - PROCESS DESCRIPTION
General

The  high  quality  standards set by detergent manufacturers
for their products necessitates  that  an  essentially  pure
sodium  phosphate  solution be used as a raw material.  This
high purity standard has greatly  limited  the  use  of  wet
process  phosphoric  acid  as  a  phosphate  source for this
industry.  One U. S. manufacturer however, does commercially
purify wet process acid to the degree necessary to allow its
use in the manufacture of  sodium  phosphate  compounds  for
detergent manufacture.

Wet process acid contains an appreciable number and quantity
of   impurities   which  must  be  removed  to  achieve  the
acceptable  detergent   purity   requirements.    The   more
significant impurities to be removed include excess sulfuric
acid,   sodium   fluosilicate,   iron   phosphate,  aluminum
phosphate and calcium sulfate.  Many  of  the  process  pro-
cedures  and techniques used for removal of these impurities
are regarded to be trade secrets.


Sodium Phosphates - Process Description

Removal of impurities from the wet process acid used in this
process begins with the phosphate  rock  used  in  the  acid
                           39

-------
Wet Process Phosphoric Acid
SODIUM PHOSPHATE PROCESS
 FROM WET PROCESS
 PHOSPHORIC ACID
MONO SODIUM
PHOSPHATE
                                                                                                                    7640-10013  1/kkg
                                                                                                                    (1830-2400  gal/s.t.)
                                                     DISODIUM PHOSPHATE
                                                     DUOHYDRATE OR
                                                     ANHYDROUS
                           DISODIUM PHOSPHATE
                              CRYSTAL
                                 TETRA SODIUM PYRO
                                      PHOSPHATE
                                                                                                             Figure  V-S

-------
manufacture.    Calcined  phosphate  rock ' is  used  in  the
acidulation step to yield a nearly colorless acid  to  start
the  purification  steps.   Rock  calcination  destroys  the
organic matter inherent in mined rock.  It is organic matter
which   causes   the   brown   coloration   that    normally
characterizes wet process phosphoric acid.

After  the initial 20-25% P205 acid is produced, the acid is
treated in a series  of  separate  neutralization  steps  to
individually  remove the various acid impurities.  The first
partial neutralization with recycled sodium phosphate liquor
is designed to  remove  the  fluosilicates.   In  this  step
granular  sodium  fluosilicate  is  precipitated and removed
from the acid solution by filtration.  This precipitate  has
commercial value as 98-99% sodium silicofluoride (Na^SiF6).

The  next  step  consists  of  adding  sodium sulfide to the
remaining solution to  precipitate  the  minor  quantity  of
arsenic  present.   Concurrently  with  this  precipitation,
barium carbonate can be added to remove the  excess  sulfate
present  as barium sulfate.  Barium carbonate is not used at
the plant producing sodium phosphates at the  present  time.
Precipitates  are  now  removed  by another filtration step.
The quantity of precipitate is small and is disposed  of  as
solid  waste.  Local landfill authorities should be notified
of the arsenic component.

At this point the partially neutralized acid still  contains
iron and aluminum phosphates, and some residual fluorine.  A
second  neutralization  is  now  made  with  soda  ash to an
approximate 4.0 pH level.   This  induces  precipitation  of
essentially    all    the   remaining   impurities.    These
precipitated  impurities  are  both  quite  voluminous   and
difficult  to separate from the remaining solution.  Special
techniques  of  heating,  agitation,   and   retention   are
necessary  to  adequately  condition  the  slurry  so that a
filtration separation of the impurities can be made.   These
impurities  contain  a relatively high quantity of P2pj> (40-
50%) and have value as  a  fertilizer  material.   Following
this   neutralization   step,   the  remaining  solution  is
sufficiently  pure  for   the   production   of   monosodium
phosphate.

Monosodium  phosphate  is  crystallized  from  the  purified
solution by concentrating the  solution  in  an  evaporator.
The   monosodium   crystals,   with   further   dehydration,
neutralization and crystallization, can be converted to such
other  compounds  as   sodium   meta   phosphate,   disodium
phosphate,  and  tri-sodium phosphate.  The several chemical
                           41

-------
equations and steps involved in this process  are  indicated
on the process flowsheet.

Water  effluents  from  these  different  processes are from
spills  and  leaks,  filtration  washes,  and  gas  scrubber
liquors.
Sodium Phosphates - Waste Characterization

The  survey  of this process was limited by the same type of
conditions and for the same  reason  which  existed  in  the
defluorinated phosphate rock process.  This was that many of
the  various unit operations are considered trade secret and
therefore  plant   access   was   necessarily   limited   to
observations  of  effluent  streams  external to the process
buildings.   As  previously   stated,   from   a   practical
standpoint  this  restricted  access takes nothing away from
the value of the study other than background information and
a better understanding of the overall process water balance.
On those items' which were basic and important to the  study,
the   industry   cooperation  and  response  to  information
requests was  excellent.   The  installed  process  effluent
measurement  and monitoring facilities were found to be well
developed and maintained.

The following  types  of  water  usage  and  effluents  were
identified.

               A.  Water Supply
               B.  Contaminated Effluent
               C.  Spills and Leaks
               D.  Non-Point Source Discharges

Each  of the above listed items are further identified below
as to flow and contaminant content.

A.  Water Supply

    Water supply is defined  as  uncontaminated  water  from
    wells.   The  water  is  used for pump seal water and in
    various  product  filtration  and  washing   procedures.
    Usage figures are listed below.

               kkg              (gal/ton)

           9,992-12,349        2,395-2,960

B.  Contaminated Effluent
                         42

-------
    This effluent is essentially the used process water with
    impurities  that were added from the process function in
    which it was used.  An effluent analysis typical  of  an
    effluent sample from Plant E is listed below.

               Contaminated Water Constituents
               Parameter
        Concentration
               pH
               Total Suspended Solids
               Total Solids
               Chloride (Cl)
               Sulfate (SO4)
               Calcium (Ca)
               Fluorine (F)
               Total Phosphorus (P)
               BOD5
               COD
               Temperature

The  following figures represent the range of water effluent
quantities found.
7.8
460
2,100
90
240
95
15.0
250
31.0
55.0
78<>F

mg/1
mg/1
mg/1
mg/1
mg/1
mg/1
mg/1
mg/1
mg/1

               1/kkg

             7,640-10,013
(gal/ton)

 1,830-2,400
C.  Leaks and Spills
    Many  manufacturers  have  demonstrated  that   spurious
    contamination  from  leaks  and spills and other sources
    can be kept at a very low level,  continuous analysis of
    pH,  conductivity  or  total  organic  carbon  is  being
    conducted on large cooling water streams so that serious
    leaks   are  almost  immediately  detected.   Corrective
    measures are put into action immediately  on  detection.
    In  many  circumstances, the system salvages products of
    sufficient value to more than  pay  for  the  monitoring
    system.     Good   housekeeping   practices,   efficient
    operation   and   prompt   maintenance   will   minimize
    contamination   of   water   from   leaks   and  spills.
    Techniques for achieving control and prevention of  such
    losses  are described in "Guidelines for Chemical Plants
    in the Prevention, Control and Reporting of  Spills"  by
    the Manufacturing Chemists Association, 1972.

    Shipping  losses  were  excluded  from the data base and
    regulations.   These  losses  are  equally  amenable  to
    control  and  prevention  as  leaks  and  spills.   Good
                            43

-------
    housekeeping,  prompt  and  regular   maintenance,   and
    careful  operations  will  tend  to minimize losses from
    shipping operations.

    No special allowance has  been  made  for  discharge  of
    cooling  water  and  other  non-process  wastewater that
    becomes contaminated by spills and leaks  or  incidental
    contact  with  raw materials, reagents or products.  The
    contaminated process wastewater allowances are  adequate
    to  take  care  of  these  incidental  sources  of water
    contamination.   It  is  the   responsibility   of   the
    manufacturer to exercise diligence in repairing leaks or
    correcting  other  conditions  that  create contaminated
    non-process wastewater so that contamination is held  to
    the lowest possible level.

D.  Non-Point Source Discharge

    The  origin  of  this discharge is primarily dry product
    which  dusts  over  the  plant   area   from   conveying
    equipment.   This product is periodically solubilized by
    rain or melting snow and collected by  the  plant  waste
    sewer  system.   In this process the non-point discharge
    is considered to be a significant periodic influence  on
    the plant effluent contaminant level.

RAW WASTE LOADS

The raw waste loads are summarized below:

Defluorinated Phosphate Rock
    Flow:  46,000 1/kkg (11,000 gal/ton)
    Total Phosphorus (P)  600   mg/1
    Fluoride  (F)        1,930   mg/1
    TSS                    16   mg/1
    pH                      1.65

Defluorinated Phosphoric Acid
    Flow: Vacuum Type Evaporation 70,500 1/kkg (16,900 gal/ton)
           Submerged Combustion   18,000 1/kkg (4,300 gal/ton)
    Total Phosphorus (P) 5,590   mg/1
    Fluoride  (F)           967   mg/1
    TSS                     30   mg/1
    pH                       1.29

Sodium Phosphates
    Flow:        7,600 - 10,000 1/kkg  (1,830 - 2,400 gal/ton)
    Total Phosphorus (P)  250   mg/1
    Fluoride  (F)           15   mg/1
    TSS                   460   mg/1
    pH                      7.8
                        44

-------
                         SECTION VI

             SELECTION OF POLLUTANT PARAMETERS
General

The  selection of pollutant parameters was a necessary early
step of  the  study.   Collection  of  meaningful  data  and
sampling  was  dependent  on knowing what fertilizer process
contaminants are important so far as degradation of  natural
water resources are concerned.

The   general   criteria  considered  and  reviewed  in  the
selection of pollutant parameters included:

- quality of the plant intake water

- products manufactured

- raw materials used

- environmental harmfulness of  the  compounds  or  elements
included in process effluent streams

Other Non-Fertilizer Phosphate Chemicals

Effluent  waste  waters from the three processes included in
this  survey  are  similar  to  those  associated  with  the
phosphate  fertilizer  industry.   The  primary  factors and
contaminants to be  controlled  to  achievable  levels  are:
suspended solids, pH, phosphorus and fluorides.

Radium  226  is  considered to be a very important raw waste
load  component.   Radium  226  coprecipitates   with   most
sedimentary  fractions, particularly at a reasonably high pH
level.  The pH 6.0 to 9.5 range set for effluent discharges,
along  with  the  limitations  as  suspended  solids,  deals
effectively  with  the  effluent problem.  The Environmental
Protection Agency has ongoing studies and is initiating  new
studies on the problem of radium-226 in recycle pond waters.
Such  studies  indicate  that  double lime treatment to a pH
range of 6.0 to 9.5 is reguired to achieve  optimum  removal
of  radium-226.   Additional information obtained from these
studies will be evaluated, and  where  appropriate,  current
effluent  guidelines  may  be amended.  Procedures currently
proposed are judged to be adequate and provide for  rigorous
control  of  radium-226.  A more detailed discussion of this
problem can be found in references N and O.
                            45

-------
Secondary parameters which should be monitored  but  do  not
warrant   definitive  guidelines  are:    temperature,  total
dissolved solids, chemical oxygen demand (COD), arsenic, and
cadmium.  The prime reason for not  setting  guidelines  for
these secondary parameters is that treatment for the primary
parameters  will  effect removal of also the secondary ones.
A considered additional reason  is  that  insufficient  data
exists from which to establish responsible guidelines.

Selection  of these parameters is justified by the fact that
best available technology economically achievable as well as
best demonstrated technology is in current commercial use.

Rationale for Selection of Parameters

Temperature

Temperature is one of the  most  important  and  influential
water quality characteristics.  Temperature determines those
species  that  may  be present; it activates the hatching of
young,  regulates  their   activity,   and   stimulates   or
suppresses  their  growth  and development; it attracts, and
may kill when the water becomes too hot or  becomes  chilled
too    suddenly.     Colder   water   generally   suppresses
development.  Warmer water  generally  accelerates  activitv
and  may  be a primary cause of aquatic plant nuisances when
other environmental factors are suitable.

Temperature is a prime regulator of natural processes within
the water environment.  It governs  physiological  functions
in   organisms   and,   acting  directly  or  indirectly  in
combination  with  other  water  quality  constituents,   it
affects  aquatic  life  with  each  change.   These  effects
include  chemical  reaction  rates,   enzymatic   functions,
molecular   movements,   and   molecular  exchanges  between
membranes within and between the physiological  systems  and
the organs of an animal.

Chemical  reaction rates vary with temperature and generally
increase as the temperature is increased.  The solubility of
gases in water varies with temperature.  Dissolved oxygen is
decreased by the decay or decomposition of dissolved organic
substances and the decay rate increases as  the  temperature
of  the  water  increases  reaching  a maximum at about 30°C
(86°F).   The  temperature  of  stream  water,  even  during
summer,   is  below  the  optimum  for  pollution-associated
bacteria.  Increasing the water  temperature  increases  the
bacterial   multiplication  rate  when  the  environment  is
favorable and the food supply is abundant.
                         46

-------
Reproduction  cycles  may  be   changed   significantly   by
increased  temperature  because  this  function  takes place
under restricted temperature ranges.  Spawning may not occur
at all because temperatures are  too  high.   Thus,  a  fish
population  may  exist  in  a  heated area only by continued
immigration.   Disregarding   the   decreased   reproductive
potential,  water  temperatures need not reach lethal levels
to decimate a species.  Temperatures that favor competitors,
predators, parasites, and disease can destroy a  species  at
levels far below those that are lethal.

Fish  food  organisms are altered severely when temperatures
approach or exceed 90°F.  Predominant algal species  change,
primary  production  is  decreased,  and  bottom  associated
organisms may be depleted or altered drastically in  numbers
and  distribution.   Increased  water temperatures may cause
aquatic plant nuisances when other environmental factors are
favorable.

Synergistic actions of pollutants are more severe at  higher
water  temperatures.   Given  amounts  of  domestic  sewage,
refinery wastes, oils, tars, insecticides,  detergents,  and
fertilizers  more  rapidly deplete oxygen in water at higher
temperatures, and the  respective  toxicities  are  likewise
increased.

When  water  temperatures  increase,  the  predominant algal
species may change from diatoms to green algae, and  finally
at high temperatures to blue-green algae, because of species
temperature   preferentials.   Blue-green  algae  can  cause
serious odor  problems.   The  number  and  distribution  of
benthic  organisms  decreases as water temperatures increase
above 90°F, which is close to the tolerance  limit  for  the
population.   This  could seriously affect certain fish that
depend on benthic organisms as a food source.

The cost of fish being attracted to heated water  in  winter
months may be considerable, due to fish mortalities that may
result when the fish return to the cooler water.

Rising  temperatures  stimulate the decomposition of sludge,
formation  of  sludge  gas,  multiplication  of  saprophytic
bacteria  and fungi  (particularly in the presence of organic
wastes), and  the  consumption  of  oxygen  by  putrefactive
processes,  thus  affecting  the  esthetic  value of a water
course.

In general, marine  water  temperatures  do  not  change  as
rapidly  or range as widely as those of freshwaters.  Marine
and  estuarine  fishes,  therefore,  are  less  tolerant,  of
                           47

-------
temperature  variation.    Although this limited tolerance is
greater in estuarine than  in  open  water  marine  species,
temperature  changes  are  more important to those fishes in
estuaries and bays than  to  those  in  open  marine  areas,
because  of  the  nursery and replenishment functions of the
estuary  that  can  be   adversely   affected   by   extreme
temperature changes.

Acidity and Alkalinity - pH

Although  not  a  specific  pollutant,  pH is related to the
acidity or alkalinity of a waste water stream.  It is not  a
linear or direct measure of either, however, it may properly
be  used  as  a surrogate to control both excess acidity and
excess alkalinity in water.  The term pH is used to describe
the  hydrogen  ion  -  hydroxyl  ion   balance   in   water.
Technically,   pH  is  the  hydrogen  ion  concentration  or
activity present in a given solution.  pH  numbers  are  the
negative  loqarithm of the hydrogen ion concentration.  A pH
of 7 generally indicates neutrality  or  a  balance  between
free  hydrogen  and free hydroxyl ions.  Solutions with a pH
above 7 indicate that the solution is alkaline, while  a  pH
below 7 indicates that the solution is acid.

Knowledge  of  the  pH  of water or waste water is useful in
determining  necessary  measures  for   corrosion   control,
pollution control, and disinfection.  Waters with a pH below
6.0  are  corrosive  to water works structures, distribution
lines, and household plumbing fixtures  and  such  corrosion
can  add   constituents  to  drinking  water  such  as iron,
copper, zinc, cadmium, and lead.  Low  pH  waters  not  only
tend  to  dissolve  metals  from structures and fixtures but
also tend to redissolve or leach  metals  from  sludges  and
bottom sediments.  The hydrogen ion concentration can affect
the  "taste"  of  the  water  and  at a low pH, water tastes
"sour".

Extremes  of  pH  or  rapid  pH  changes  can  exert  stress
conditions  or  kill  aquatic  life  outright. Even moderate
changes  from  "acceptable"  criteria  limits  of   pH   are
deleterious  to  some  species.   The  relative toxicity* to
aquatic life of many materials is increased  by  changes  in
the  water  pH.   For  example,  metalocyanide complexes can
increase a thousand-fold in toxicity with a drop of   1.5  pH
units.   Similarly, the toxicity of ammonia is a function of
pH.  The bactericidal effect of chlorine in  most  cases  is
less   as   the   pH   increases,  and  it  is  economically
advantageous to keep the pH close to 7.
*The term toxic or toxicity is used herein in the normal
scientific sense of the word and not as a specialized
term referring to section 307 (a) of the Act.

                           48

-------
Acidity is defined as the quantitative ability of a water to
neutralize hydroxyl ions.  It is usually  expressed  as  the
calcium   carbonate   equivalent   of   the   hydroxyl  ions
neutralized.  Acidity should not be confused with pH  value.
Acidity  is  the  quantity  of  hydrogen  ions  which may be
released to react with or neutralize hydroxyl ions while  pH
is  a measure of the free hydrogen ions in a solution at the
instant the pH measurement is  made.   A  property  of  many
chemicals,  called  buffering,  may  hold hydrogen ions in a
solution from being in the free state and being measured  as
pH.   The  bond  of most buffers is rather weak and hydrogen
ions tend to be  released  from  the  buffer  as  needed  to
maintain a fixed pH value.

Highly  acid  waters  are  corrosive to metals, concrete and
living organisms, exhibiting the pollutional characteristics
outlined above for low pH waters.   Depending  on  buffering
capacity, water may have a higher total acidity at pH values
of 6.0 than other waters with a pH value of U.O.

Alkalinity;  Alkalinity is defined as the ability of a water
to neutralize hydrogen ions.  It is usually expressed as the
calcium  carbonate   equivalent   of   the   hydrogen   ions
neutralized.

Alkalinity is commonly caused by the presence of carbonates,
bicarbonates,  hydroxides and to a lesser extent by borates,
silicates, phophates and organic substances.  Because of the
nature  of  the  chemicals  causing  alkalinity,   and   the
buffering  capacity of carbon dioxide in water, very high pH
values are seldom found in natural waters.

Excess alkalinity as exhibited in a high pH value  may  make
water  corrosive  to  certain  metals,  detrimental  to most
natural organic materials and toxic to living organisms.

Ammonia is more lethal with a higher pH.  The lacrimal fluid
of the human eye  has  a  pH  of  approximately  7.0  and  a
deviation  of  0.1  pH  unit from the norm may result in eye
irritation for the  swimmer.   Appreciable  irritation  will
cause severe pain.

Total Suspended Solids

Suspended   solids   include   both  organic  and  inorganic
materials.  The inorganic compounds include sand, silt,  and
clay.   The  organic  fraction  includes  such  materials as
grease, oil, tar, and animal and vegetable  waste  products.
These  solids may settle out rapidly and bottom deposits are
often a  mixture  of  both  organic  and  inorganic  solids.
                         49

-------
Solids may be suspended in water for a time, and then settle
to  the  bed of the stream or lake.  These solids discharged
with  man's  wastes  may  be  inert,  slowly   biodegradable
materials,  or  rapidly  decomposable  substances.  While in
suspension, they increase the turbidity of the water, reduce
light penetration and impair the photosynthetic activity  of
aquatic plants.

Suspended  solids  in  water  interfere with many industrial
processes, cause foaming in  boilers  and  incrustations  on
equipment   exposed   to   such  water,  especially  as  the
temperature rises.  They are undesirable  in  process  water
used  in  the manufacture of steel, in the textile industry,
in laundries, in dyeing, and in cooling systems.

Solids in suspension are  aesthetically  displeasing.   When
they  settle  to  form sludge deposits on the stream or lake
bed, they are often damaging to the life in water.   Solids,
when  transformed  to  sludge  deposits, may do a variety of
damaging things, including blanketing the stream or lake bed
and thereby destroying the living spaces for  those  benthic
organisms  that would otherwise occupy the habitat.  When of
an organic nature, solids  use  a  portion  or  all  of  the
dissolved  oxygen  available in the area.  Organic materials
also serve as a food source for sludgeworms  and  associated
organisms.

Disregarding  any  toxic  effect  attributable to substances
leached out by water, suspended solids  may  kill  fish  and
shellfish  by  causing abrasive injuries and by clogging the
gills and respiratory passages  of  various  aquatic  fauna.
Indirectly,  suspended  solids  are inimical to aquatic life
because they screen out light, and they promote and maintain
the  development  of  noxious  conditions   through   oxygen
depletion.   This  results  in  the killing of fish and fish
food  organisms.    Suspended   solids   also   reduce   the
recreational value of the water.

Turbidity;  Turbidity  of  water is related to the amount of
suspended and colloidal matter contained in the  water.   It
affects  the clearness and penetration of light.  The degree
of  turbidity  is  only  an  expression  of  one  effect  of
suspended solids upon the character of the water.  Turbidity
can  reduce the effecteveness of chlorination and can result
in  difficulties  in  meeting  BOD  and   suspended   solids
limitations.   Turbidity is an indirect measure of suspended
solids.
                            50

-------
Fluorides

Fluorine is the most reactive of the nonmetals and is  never
found  free  in  nature.  It is a constituent of fluorite or
fluorspar, calcium fluoride, cryolite, and  sodium  aluminum
fluoride.    Due   to   their  origins,  fluorides  in  high
concentrations are  not  a  common  constituent  of  natural
surface   waters;  however,  they  may  occur  in  hazardous
concentrations in ground waters.

Fluoride can be found in plating rinses and in glass etching
rinse waters.  Fluorides are also used  as  a  flux  in  the
manufacture  of steel, for preserving wood and mucilages, as
a disinfectant and in insecticides.

Fluorides in sufficient quantities are toxic to humans  with
doses  of 250 to 450 mg giving severe symptoms and 4.0 grams
causing death.  A concentration of 0.5 g/kg of  body  weight
has been reported as a fatal dosage.

There  are  numerous  articles  describing  the  effects  of
fluoride-bearing waters on dental enamel of children;  these
studies  lead  to  the  generalization that water containing
less than 0.9 to 1.0 mg/1  of  fluoride  will  seldom  cause
mottled  enamel  in children, and for adults, concentrations
less than 3 or 4  mg/1  are  not  likely  to  cause  endemic
cumulative   fluorosis   and   skeletal  effects.   Abundant
literature is also available describing  the  advantages  of
maintaining  0.8  to  1.5  mg/1  of fluoride ion in drinking
water to aid in the reduction of  dental  decay,  especially
among  children.  The recommended maximum levels of fluoride
in public water supply sources range from 1.4 to 2.4 mg/1.

Fluorides may be harmful in certain industries, particularly
those  involved  in  the  production  of  food,   beverages,
pharmaceutical,   and   medicines.    Fluorides   found   in
irrigation waters in high concentrations (up  to  360  mg/1)
have  caused  damage  to  certain  plants  exposed  to these
waters.  Chronic fluoride poisoning of  livestock  has  been
observed  in  areas  where  water  contained  10  to 15 mg/1
fluoride.  Concentrations of 30 - 50 mg/1 of fluoride in the
total ration of dairy cows  is  considered  the  upper  safe
limit.   Fluoride from waters apparently does not accumulate
in soft tissue to a significant degree and it is transferred
to a very small extent into  the  milk  and  to  a  somewhat
greater  degree  into  eggs.   Data for fresh water indicate
that fluorides are toxic to fish  at  concentrations  higher
than 1.5 mg/1.
                          51

-------
Phosphorus

Phosphorus  occurs  in natural waters and in waste waters in
the form of various types of  phosphate.   These  forms  are
commonly    classified   into   orthophosphates,   condensed
phosphates   (pyro-,   meta-,   and   polyphosphorus) ,   and
organically  bound  phosphates.   These  may  occur  in  the
soluble form, in particles of detritus or in the  bodies  of
aquatic organisms.

The  various  forms  of phosphates find their way into waste
waters  from  a  variety  of  industrial,  residential,  and
commercial  sources.   Small  amounts  of  certain condensed
phosphates are added to some water supplies in the course of
potable water  treatment.   Large  quantities  of  the  same
compounds may be added when the water is used for laundering
or   other   cleaning   since   these  materials  are  major
constituents  of  many  commercial  cleaning   preparations.
Phosphate  coating  of  metals  is  another  major source of
phosphates in certain industrial effluents.

The increasing problem of the growth of algae in streams and
lakes appears to be associated with the increasing  presence
of   certain  dissolved  nutrients,  chief  among  which  is
phosphorus.  Phosphorus is an element which is essential  to
the  growth  of  organisms  and it can often be the nutrient
that limits the aquatic growth that  a  body  of  water  can
support.    In  instances  where  phosphorous  is  a  growth
limiting nutrient, the  discharge  of  sewage,  agricultural
drainage  or  certain industrial wastes to a receiving water
may  stimulate  the  growth,  in  nuisance  quantities,   of
photosynthetic aquatic microorganisms and macroorganisms.

The  increase  in  organic  matter  production  by algae and
plants in a lake undergoing eutrophication has ramifications
throughout the aquatic ecosystem.  Greater demand is  placed
on  the  dissolved oxygen in the water as the organic matter
decomposes at the termination of the life  cycles.   Because
of  this  process,  the deeper waters of the lake may become
entirely  depleted  of  oxygen,  thereby,  destroying   fish
habitats   and  leading  to  the  elimination  of  desirable
species.   The  settling  of  particulate  matter  from  the
productive  upper layers changes the character of the bottom
mud, also leading to the replacement of certain  species  by
less  desirable  organisms.  Of great importance is the fact
that nutrients inadvertently introduced to a lake  are,  for
the  most  part,  trapped  there and recycled in accelerated
biological processes. Consequently, the  damage  done  to  a
lake  in  a  relatively  short time requires a many fold in-
crease in time for recovery of the lake.
                          52

-------
When a plant population  is  stimulated  in  production  and
attains  a  nuisance  status,  a  large number of associated
liabilities are immediately apparent.  Dense populations  of
pond  weeds  make  swimming  dangerous.   Boating  and water
skiing and sometimes fishing may be  eliminated  because  of
the mass of vegetation that serves as an physical impediment
to  such activities.  Plant populations have been associated
with stunted fish populations and with poor fishing.   Plant
nuisances  emit  vile  stenches,  impart tastes and odors to
water supplies, reduce  the  efficiency  of  industrial  and
municipal  water  treatment, impair aesthetic beauty, reduce
or restrict resort trade, lower waterfront property  values,
cause  skin rashes to man during water contact, and serve as
a desired substrate and breeding ground for flies.

Phosphorus in the elemental form is particularly toxic,  and
subject  to bioaccumulation in much the same way as mercury.
Colloidal  elemental  phosphorus  will  poison  marine  fish
(causing  skin  tissue  breakdown and discoloration).  Also
phosphorus  is  capable  of  being  concentrated  and   will
accumulate  in  organs  and  soft tissues.  Experiments have
shown that marine  fish  will  concentrate  phosphorus  from
water containing as little as 1 ug/1.

Radioactivity

Ionizing  radiation,  when  absorbed  in  living  tissue  in
quantities substantially above that  of  natural  background
levels,  is  recognized  as  injurious.   It  is  necessary,
therefore, to prevent excessive  levels  of  radiation  from
reaching   any   living   organism   humans,   fishes,   and
invertebrates.  Beyond the  obvious  fact  that  radioactive
wastes  emit  ionizing  radiation,  they are also simile:, in
many respects to other chemical wastes.  Man's senses cannot
detect radiation unless it is present in massive amounts.

Plants and animals, to be of any significance in the cycling
of radionuclides in the aquatic environment, must accumulate
the radionuclide, retain it, be eaten by  another  organism,
and be digestible.  However, even if an organism accumulates
and  retains a radionuclide and is not eaten before it dies,
the radionuclide will enter the "biological  cycle"  through
organisms  that decompose the dead organic material into its
elemental  components.   Plants  and  animals  that   become
radioactive  in this biological cycle can thus pose a health
hazard when eaten by man.

Aquatic  life  may  receive  radiation  from   radionuclides
present   in   the   water   and  substrate  and  also  from
radionuclides that  may  accumulate  within  their  tissues.
                             53

-------
Humans  can  acquire  radionuclides  through  many different
pathways.  Among the most  important  are  through  drinking
contaminated  water, and eating fish and shellfish that have
concentrated nuclides from the water.  Where fish  or  other
fresh  or  marine products that have accumulated radioactive
materials are used as food by humans, the concentrations  of
the  nuclides  in  the  water must be further restricted, to
provide assurance that the  total  intake  of  radionuclides
from all sources will not exceed the recommended levels.

In  order  to  prevent  unacceptable doses of radiation from
reaching humans, fish, and other  important  organisms,,  the
concentrations  of  radionuclides  in  water, both fresh and
marine, must be restricted.

Radium-226

Radium-226 is one of the most hazardous radioisotopes of the
uranium decay scheme, when present in water.  The human body
preferentially utilizes  radium  in  lieu  of  calcium  when
present  in  food  or drink.  Plants and animals concentrate
radium, leading to a multiplier effect up the food web.

Radium-226 decays by alpha emission into radon-222, a radio-
active gas with a half life of 3.8 days.  The decay products
of  radon-222,  in  turn,  are  particulates  which  can  be
adsorbed  onto  respirable particles of dust.  Radon and its
decay products has been implicated in an increased incidence
of lung cancer in  those  workers  exposed  to  high  levels
(Bureau  of  Mines, 1971).  Heating or grinding of phosphate
rock would liberate radon and  its  decay  products  to  the
surrounding atmosphere.

It is generally agreed that unlike other materials, there is
no threshold value for radiation exposure.  Accordingly, the
Federal  Radiation  Council  has  repeatedly stated that all
radiochemical material  releases  are  to  be  kept  to  the
minimum  practicably  obtainable.   The  Council  states "It
should be general practice to reduce exposure to  radiation,
and  positive  efforts  should be carried out to fulfill the
sense of these recommendations.  It is basic  that  exposure
to  radiation should result from a real determination of its
necessity  (Federal Radiation Council, I960)."
                            54

-------
                    METHODS OF ANALYSIS
The  methods  of  analy.sis  to  be  used  for   quantitative
determination  are  given in the Federal Register 40 CFR  136
for the following parameters pertinent to this study:
                  Alkalinity  (and Acidity)
                  fluoride
                  oxygen demand, chemical
                  total phosphorus  (as P)
                  solids, total
                  suspended nonfilterable solids, total
                  temperature
                             55

-------

-------
                        SECTION VII

              CONTROL AND TREATMENT TECHNOLOGY

The factors and  contaminants  in  non-fertilizer  phosphate
chemical  process  effluent  streams  have for the most part
been well identified and well known for many  years.   As  a
consequence considerable effort has been expended to correct
or  minimize  the  majority  of those which are particularly
detrimental to natural water receiving bodies.  Much of this
work has been directed  at  correcting  the  source  of  the
contamination  or  an  in-process improvement rather than an
end-ofpipe  type  of  treatment.   A  large  part   of   the
motivation  for  such  improvement has been economics - that
is,  improved  operating   efficiency   and   costs.    Such
improvements  are  just  plain  good  business  and  justify
capital expenditure required to achieve them.

With an appreciation  of  the  above  mentioned  facts,  the
following   criteria   were   established   as   bases   for
investigating treatment technology.

- A determine the extent of existing waste water control and
treatment technology

- A determine the availability  of  applicable  waste  water
control and treatment technology regardless of whether it be
intra-industry transfer technology

- A determine the degree of treatment cost reasonability

Based  upon  these  stated  criteria  the effort was made to
factually investigate overall treatment technologies dealing
with each of the primary factors and contaminants listed  in
Section VI.

Process  technology  does exist both for containment and for
treatment and reduction of the and contaminants  present  in
the non-fertilizer phosphate chemical wastewaters as defined
in  Section  VI.  These processes have been divided into two
separate technologies to make them better adaptable  to  all
the  processes.   For example, in two of the processes it is
very possible that both technologies need  to  be  used  and
therefore  be  considered  as a single treatment method.  In
another process however it would be somewhat impractical  to
consider  using  more  than one of the technologies although
they are closely inter-related.  These two technologies  are
therefore  described separately even though it is recognized
that they may be essentially integral in some cases.
                             57

-------
Containment and Cooling Pond

The above title provides a reasonably precise description of
this technology.  The pond retains sufficient wastewater  to
meet  the  high  demand  for cooling water, particularly for
stack and tail gas scrubbing operations.  The  pond  surface
provides  cooling.   An indication of the land area used for
this purpose is shown  by  the  fact  that  survey  plant  A
utilizes  approximately  0.11  hectare  (0.26 acre) per daily
production ton.  This figure also includes area adequate  to
provide   collection  of  excessive  rainfall  until  normal
conditions can be restored.

Acids  are  collected   in   the   wastewater   diring   the
manufacturing operations.  Insufficient basic substances are
present  to  neutralize these acids.  Lime neutralization is
provided in some manner at each plant to  prevent  excessive
air  pollution  by stack or tail gases.  Lime may be applied
to the wastewater pumped to the stack, directly to the  pond
in  a  clarifier  treating  a  fraction  of the pond recycle
water.  The clarifier removes sulfate fluoride and phosphate
as precipitate.   The  neuralized  supernatant  fraction  is
returned   to  the  pond.   One  plant  manufactures  sodium
fluosilicate from the fluoride derived from the distillation
process.

Factors in Pond Construction and Management that Provide
Pond Reliability and Efficiency of Operation

A.  Prevention of Dike Failure

Dike failure has been by far the greatest cause of navigable
water contamination from phosphate mining operations.   Many
slime  pond  dike failures have occurred.  These have caused
massive contamination of surface waters.  Dike failures have
also been reported for containment and cooling ponds.

A potential hazard,  therefore,  exists  from  gyp-pond  and
recirculation   cooling   pond  dikes,  although  these  are
generally much smaller structures than the slime pond dikes.
Gypsum derived from  total  manufacturing  and  waste  water
treatment  practices  is  the  only  dike  material  readily
available at many sites.  It is not an  ideal  material  for
construction  of dams.  A dam constructed entirely of gypsum
has a uniform and relatively high permeability.  Water seeps
through the structure.  Saturation is maintained in much  of
the  dam  mass unless special provision is made for drainage
of the toe.  Some States maintain a degree of regulation  of
dikes.  The State of Illinois requires some underdrainage of
gyp-pond dikes at Joliet, Illinois.
                           58

-------
A  saturated  dam  is  weakened in a number of ways.  Piping
occurs in the outer toe.  The water in  the  dam  buoys  the
structural  material,  reducing  the dikes effective weight.
Granular  materials  saturated  with   water   will   become
momentarily  fluid  if  an earthquake or a shock wave of any
type sets up a tremor.

Hazardous  conditions  are  common  in   pond   dams.    The
contractors  diagram  of  a  typical dam, supplied with this
study, indicates, no provision of underdrainage.   The  lack
of  specifications  that make dikes safe, and/or the lack of
enforcement  of  these  specifications  can  lead  to   dike
failures.

A gyp-pond or recirculation pond dike must be constructed in
a manner that maintains effective drainage in the outer half
of  the dike.  If gypsum is the sole material in the dike, a
farm tile  (or other equally effective)  underdrainage  system
should  be  provided in the toe of the dike.  The tile lines
must be close enough together,  located  below  sufficiently
permeable  liner  materials and sloped adequately.  The tile
field  must  remain  operational   and   drain   effectively
throughout  the  entire  period  of waste water containment.
The engineering details of any  new  gyp-pond  utilized  for
treating   the  waste  water  in  the  other  non-fertilizer
phosphate chemicals segment of the  phosphate  manufacturing
should be based on sound engineering fundamentals and should
be  in  compliance  with  applicable local, State or federal
regulations.

In the event of declining efficiency of a  drainage  system,
relief  wells  should  be  provided to maintain the drainage
function.

Both a relief well  system  or  a  farm  tile  underdrainage
system  leading  to an underground sump have many advantages
over the open ditches commonly utilized  to  catch  seepage.
The  underground  systems  permit  return of seepage without
lowering the outer edge of the dam.   This  strongly  favors
dike   safety.    The  ditch  alone  provides  none  of  the
underdrainage required to make the dam safe.

An inherent advantage of the underground sump or relief well
system is that seepage can be returned to the lagoon free of
outer slope rain run-off water.  A ditch is not essential to
collect this runoff water where a sound  underdrain  seepage
control system is provided.

Planting  the  dam slopes with low plants can be utilized to
improve the water balance and to stabilize the dam  surface.
                             59

-------
Tall  plants that reduce wind velocity over the pond surface
must be avoided.  Wind is an aid to cooling.

The U.S. Department of Interior, Bureau of Reclamation, book
"Design of Small Dams" (Reference  L)   presents  discussions
and  diagrams  of  toe  draining  systems, with a horizontal
drainage blanket, an underground  drainage  trench,  and  an
underground pipe conduit leading to an outfall.  This system
can  readily  replace the open seepage interceptive ditch in
common use.  The intercepted seepage can be pumped  back  to
the  pond  from  an  underground sump.  This system does not
return runoff from outer slopes to the lagoon.

The reliability of a properly installed underground drainage
system is extremely high.  A soundly designed system assures
a safe dam for its full service life.

If some local factor introduces a  reliability  problem  two
control measures should be considered:

1.  Install a conduit to  the  top  altitude  of  the  drain
    system  for  periodic  drain  pipe  flushing  to prevent
    plugging.

2.  Install a vertical permeable pipe at the center  of  the
    dam,  through  which  the phreatic line may be measured.
    The design engineer  should  specify  the  maximum  safe
    height  of  this  phreatic  line  for each dam.  Various
    instruments can be installed in the dike to monitor  the
    height  of  the  phreatic  line.  These must be of fully
    established reliability.

B.  Control of Seepage

A pond, to be acceptable for use in waste  water  treatment,
must  have  an  interceptor system that collects and returns
seepage, or should be provided with a  liner  that  prevents
significant percolation, and that blocks flow to groundwater
through  underground channels.  Furthermore,  any waste water
seepage must have no dissolving action on underlying layers.
It is particularly important to prevent acidic  waste  water
seepage  through  limestone  formations.  Some liming may be
required, particularly at  start-up,  to  protect  limestone
layers,  to  provide  sediment  for  plugging  of the bottom
liner, and to prevent seepage of  fluoride,  radium-226  and
phosphate components.

Relief  wells, underdrainage or other provision must be made
to prevent upflow of groundwater into  the  lagoon.   Upflow
into  a  lagoon normally breaches the liner and permits flow
                            60

-------
of waste water through existent channels to groundwater when
lagoon  hydrostatic   pressure   exceeds   the   groundwater
pressure.

Groundwater  monitoring by ifieans of wells in the percolation
area should be installed whenever  the  lagoon  is  provided
with  a  liner of questionable impermeability.  The addition
of  lime  to  bottom  sediments  in  lagoons  will  lead  to
neutralization  of  waste  water  seeping into ground water.
The use of lime will  also  provide  sedimentary  conditions
that tend to block seepage.

The  liming  of  pond  water can be utilized to aid both air
pollution  control  and  to  reduce  loss  of  waste   water
pollutants by seepage.

C.  Deposits of Objectionable Substances at
    Phosphate Manufacturing Plants

Various deposits of  objectionable  waste  water  components
occur  in  ponds  or  landfill areas.  Examples of these are
calcium fluoride, radium-226, arsenic  and  sulfide.   Local
State  and  EPA  authorities  with  jurisdiction  over  this
landfill problem should be notified of the deposits and  the
control measures required should then be established.  It is
vital that percolating water does not carry these substances
into ground water or into surface waters.

D.  Ponds in Regions with Severe Cold Seasons

The cooling problem for a  reuse  and  cooling  pond  varies
drastically  from summer to winter seasons in cold climates.
It  is  essential  to  install  conduits   underground,   or
otherwise protect from freezing.  Provision must be made for
isolation  of  a pond with a limited surface area for winter
operation.  The  heat  discharged  to  the  pond  in  normal
operation  will then prevent troublesome freezing incidents.
The winter pond must be deep enough to remain operable after
a plant shutdown.   A  defluorinated  rock  plant  has  been
operating a recycle pond in Montana.  No difficulty has been
reported.

National  standards are not being proposed for recirculation
and reuse ponds.  Some State and local authorities have  set
standards.  Monitoring should cover the factors that control
loss  of waste water to surface and ground waters, and local
authorities should be  notified  of  conditions  threatening
navigable and ground waters with pollution.
                            61

-------
Contaminated (Pond)  Water Treatment

This  technology  is  identical to that treatment technology
designated as gypsum pond (contaminated)  water treatment  in
the phosphate fertilizer section of the development document
for the Basic Fertilizer Chemicals Manufacturing Industry.

The  Containment and Cooling Pond technology described above
is intended to function as a no discharge closed loop system
the majority of the time.  This "no discharge" situation  is
however  dependent  upon  the  quantity  of  rainfall it can
accept before its water storage capacity is exceeded.   Once
the  storage  area  approaches  capacity  it is necessary to
begin  treating  the  contaminated  water   for   subsequent
discharge  to  natural  drainage areas.  Similarly, in those
processes in which a containment pond is impractical it  may
be  necessary to continuously treat the contaminated process
effluent water.  This technology in part or as  a  whole  is
capable  of treating the contaminated effluent of either the
containment pond or the process effluent streams.

Process Description

Contaminated water can be treated effectively for control of
the pollution parameters identified in  Section  VI,  namely
suspended  solids, pH, phosphate, radium-226, and fluorides.
The treatment described is by means of either single or two-
stage  lime  neutralization  procedure.    In   the   Sodium
Phosphate  process  there  are  indications that only single
liming is required for removal of the impurities.

Normally  two  stages  of  liming  or   neutralization   are
necessary to effect an efficient removal of the fluoride and
phosphate  contaminants.  Fluorides are present in the water
principally  as  fluosilicic  acid  with  small  amounts  of
soluble  salts  as  sodium  and  potassium fluosilicates and
hydrofluoric acid.  Phosphorus  is  present  principally  as
orthophosphoric  acid  with  some  minor  amounts of soluble
calcium orthophosphates in the conventional  wet  phosphoric
acid   production   process.   Polyphosphates  that  require
special pretreatment prior  to  lime  sedimentation  may  be
present in lagoons accepting waste water from defluorination
processes,  and from the manufacture of defluorinated (poly)
phosphates.

The first treatment stage provides sufficient neutralization
to raise the contaminated water containing up to 9,000  mg/1
F  and  up  to  6,500 mg/1 P from pH 1-2 to pH 3.5-4.0.   The
resultant  treatment  effectiveness  is,  to  a  significant
degree, dependent upon the mixing efficiency at the point of
                            62

-------
lime  addition and the constancy of the pH control.  At a pH
level  of  3.5  to  U.O,  the  fluorides  will   precipitate
principally  as  calcium  fluoride  (CaF2_)  as  shown by the
following chemical equation.
  H2SiF£  +

Fluosilicic
  Acid
             3 CaO  +  H20   =  3 CaF2  +  2 H20
               Lime
        Water
         Calcium
          Water
This mixture is then held in a quiescent area to
particulate CaF2 to settle.
Silica
                                   allow  the
Equipment  used  for neutralization ranges from crude manual
distribution of lime with  localized  agitation  to  a  well
engineered  lime  control system with a compartmented mixer.
Similarly the  quiescent  areas  range  from  a  pond  to  a
controlled,   settlina   rate  thickener  or  settler.   The
partially neutralized water following  separation  from  the
CaF2_r  (pH 3.5-4.0)  now contains 30-60 mg/1 F and up to 5,500
mg/1 P.  This water is again treated with lime sufficient to
increase  the  pH  level  to 6.0 or above.  At this pH level
calcium  compounds,  primarily  dicalcium   phosphate   plus
additional  quantities  of  CaF2  precipitate from solution.
The primary reactions are shown by  the  following  chemical
equation:
   2 H3P04  +
 Phosphoric
   Acid

   Ca(H2POj*) 2
 Monocalcium
  Phosphate
CaO  +
Lime
   CaO
   Lime
H20
Water
   H20
   Water
 Ca (E2PQI4) 2    +    2 H_20
Monocalcium         Water
    Phosphate

   2CaHPO4_    +    2 H20
  Dicalcium        Water
      Phosphate
As  before,  this mixture is retained in a quiescent area to
allow the CaHPOJ4 and minor amounts of CaF2_ to settle.

After settlement, the clear, neutralized water will  contain
15-30 mg/1 F and 30-60 mg/1 P at a pH of 6-8.  The reduction
of the P value is strongly dependent upon the final pH level
and  quality  of the neutralization facilities, particularly
mixing efficiency.  Neutralization to pH levels of 9-11 will
reduce P values to 15-30 mg/1 or less.  Figure VII-1 shows a
sketch of a well designed "double lime" treatment  facility.
Plants B, C and D all practice some degree of liming.
                         63

-------
                 TO GYPSUM POND
                                                    CALCIUM PHOSPHATE
                                                          POND
CONTAMINATED  (POND) WATER TREATMENT
                                                        TO RIVER OR
                                                        PROCESS UNITS
                                                      FIGURE VII-1

-------
A  number  of  pollutants  may  cause interference with lime
precipitation.  Silicates  are  normal  components  of  most
recycle  ponds  and  exert  an  interfering  action  through
formation  of  fluosilicates.   Some  boron  componds   will
complex  fluorine  and  interfere with precipitation.  Borax
has a chelating action on calcium ion  and  therefore,  like
many  other  chelating  agents, has an interfering action on
lime precipitation.  Spurious  contaminants  that  interfere
with  lime precipitation must be excluded from recycle ponds
if satisfactory lime precipitation is to be maintained.

Some special precautions are essential at a plant  producing
sodium  phosphates.  All meta, tetra, pyro and polyphosphate
waste water in spills should be diverted to the reuse  pond.
These  phosphates will not precipitate satisfactorily in the
lime treatment process and will interfere with  the  removal
of fluoride and suspended solids.

Polyphosphate  in  waste  water will exert a desirable anti-
fouling action if diverted to the cooling water stream  from
the  reuse lagoon.  Furthermore, the compound will hydrolyze
and precipitate in the lagoon.

Domestic  waste,   unless   completely   bio-oxidized,   has
undesirable effects in sodium phosphate plant effluent.  The
amino acids and other organic components interfere with both
precipitation  and  flocculation.  The high calcium level of
the recycle pond is lacking in the waste water  stream  from
the  sodium  phosphate plant.  Lime and/or calcium salts may
be required for acceptable removal of P  and  F  pollutants.
Adequate  precipitant  reagent  use  must  be  supported  by
effective clarification for control of F, P and SS.

In some circumstances it may be desirable  to  strip  carbon
dioxide  from the waste stream before lime treatment so that
carbonate  does  not   compete   with   phosphate   in   the
precipitation reaction.

The  sodium  phosphates  subcategory  manufacturing  process
utilizes a series of salting out  processes  for  separating
various  crystallized  products.   The resultant waste water
streams contain a variety of  contaminants  that  cannot  be
recycled   in   the  process  without  degenerating  product
quality.  The manufacturing processes isolate  some  of  the
potential  waste  water  pollutants  from  the waste stream.
Sodium silicofluoride is precipitated  out  and  sold  as  a
byproduct;  this process disposes of most of the troublesome
fluoride problem.  Radium 226  is  segregated  into  various
sediment   fractions.    Arsenic  is  separated  as  sulfide
precipitate.  Sedimentation occurs in the waste streams from
                        65

-------
the sodium phosphate processes and the sediments are removed
by clarification.  The technical details of these  processes
have not been fully disclosed by the manufacturer.

A  recirculation  pond is available on the site for handling
difficult waste water streams to the same extent  that  this
lagoon  system  is available for defluorinated rock and acid
waste water.

Modified  forms  of  phosphate  create  a  unique  treatment
problem  at  defluorination  plants.  Phosphoric acid and/or
phosphate  salts  undergo   polymerization   and   molecular
rearrangement reactions when subjected to severe dehydration
treatment.   The  acid defluorination treatments applied are
predominantly operated with application of heat  and  a  gas
stripping  action.   These  heating and/or stripping actions
induce a substantial degree of molecular conversion  in  the
defluorinated acids.  The conversion is particularly high in
super-acid  grades  concentrated  to  a  high  P.205 content.
Likewise,   the   high   temperatures   applied   for   rock
defluorination   convert  the  raw  orthophosphate  rock  to
polyphosphates.

These    modified    phosphates    differ    sharply    from
orthophosphates in solubility.  Calcium orthophosphates have
extremely  low  solubility in moderately alkaline solutions;
the  calcium  salts  of   the   modified   phosphates   have
appreciable  solubility.  In fact, these modified phosphates
are  applied  extensively  as  chelating  agents  to  combat
calcium  induced  hardness.   These  modified phosphates are
relatively stable at ambient temperatures.   The  half  life
varies from compound to compound and is poorly defined; this
half  life  is  commonly  taken to be about 2 days in acidic
waters, but is several weeks in neutral or alkaline waters.

These modified phosphates enter the process waste water from
various sources.  Stack washing introduces  some  dust  from
rock   defluorination.    Spray   carryover   to  barometric
condenser water is a common source of contamination in  acid
defluorination.   Spills and leaks carry polyphosphates into
waste water in all the  subcategories.   Rain  run-off  from
drying,  packaging,  loading  and shipping areas carry these
modified phosphates into the waste water stream.

It is vitally  important  that  waste  water  bearing  these
modified phosphates be excluded from streams flowing to lime
treatment   facilities;  this  is  especially  objectionable
without impoundment.  The calcium salts  of  these  modified
phosphates   are   much   more   soluble  than  the  calcium
orthophosphate salts.  Satisfactory phosphate  precipitation
                         66

-------
will    not   occur   on   lime   treatment.    Furthermore,
polyphosphates exert an objectionable interference action on
clarification processes.  And  still  further,  the  soluble
calcium salts of molecular species other than orthophosphate
act  as  individual  agejits  in  the  calcium  precipitation
process.  Thus,  a  system  with  only  orthophosphate  will
remain  saturated  with  calcium  orthophosphate.  The mixed
system will remain saturated with calcium orthophosphate and
with each component  calcium  phosphate.   The  sum  of  the
phosphate  components  in  solution  will be higher than the
orthophosphate component alone.

Where  waste  water  contamination  does  occur  with  these
modified  phosphates, the resultant waste streams, should be
directed to a special holding pond, along with acidic wastes
that speed hydrolysis.   Completing  of  hydrolysis  can  be
promoted  further  by  discharge into the contaminated water
recirculation pond.  The modified  phosphates  continue  the
hydrolysis  to  orthophosphate  in the recirculation lagoon.
This factor adds another plus value to the  desirability  of
the  recirculation  and reuse lagoon at a phosphate facility
with defluorination processes.  The  holding  is  especially
beneficial  at  the  typical  low  pH  levels  prevailing in
typical   contaminated   water   ponds.    Acidity   hastens
hydrolysis to the orthophosphate form.

A  unique  condition  prevails  in the waste water discharge
from the single plant  producing  sodium  phosphates.   This
stream  also  contains the domestic waste discharge from the
septic tanks' accepting  the  plant's  domestic  sewage.   An
efficient  aerobic  bio-oxidation step applied to this waste
water would destroy most  of  the  organic  substances  that
interfere   with   sedimentation;   furthermore,  this  bio-
oxidation  process   will   catalyze   the   hydrolysis   of
polyphosphates present in the waste water to orthophosphate.
Bio-oxidation   may   be   the  most  practicable  means  of
converting any polyphosphates present to  orthophosphate  in
this  situation.  The waste stream is neutral; hydrolysis of
polyphosphates will be extremely slow  unless  bio-catalytic
action  is  induced  in  the  system.   Many  microorganisms
produce   enzymes   that   catalyze   the   hydrolysis    of
polyphosphates.  Reference P brings out the observation that
no  problem  was  encountered in precipitating phosphates in
domestic waste water following bio-oxidation  of  the  waste
water.

It  must  be  recognized that pH alone does not indicate the
total  effectiveness  of  the  precipitating  reagent.   The
calcium  content in the pond water will also be a factor and
will vary widely.  The sulfate ion competes for the  calcium
                          67

-------
ion;  a high sulfate content will tend to reduce the calcium
content  of  a  pond  and  create  a  condition   relatively
unfavorable  for  fluoride and phosphate precipitation.  The
pH  change  induced  by  lime  addition,  gives  a   general
indication  of the precipitation potential in the system.  A
pH rise from lime addition  is  accompanied  by  a  rise  in
soluble  calcium  content.  In normal circumstances, lime to
pH 6.0 will  be  adequate  for  precipitating  fluorine  and
phosphate  to  meet required limitations, but lime will have
to  be  added,  as  required,  if  fluoride  and   phosphate
limitations are not met.

Soluble  iron  and  aluminum  compounds  are present at high
concentrations in many ponds.  The iron and aluminum cations
exert a strong influence on phosphate precipitation.

Strong winds interfere with  sedimentation  in  lagoons.   A
covered  terminal  sedimentation  basin,  or a covered final
segment of a sedimentation basin will be  indispensable  for
attaining  satisfactory  suspended solids removal under many
conditions.  A cover is particularly beneficial  in  periods
of  cold  weather.   Temperature  inversion  currents  cause
severe disturbance of sedimentation in open basins  in  cold
weather.    Inlet  and  outlet  arrangements  are  critical.
Poorly designed inlets and outlets  permit  excessive  short
circuiting.   Arrangements that direct flow tangentially are
vastly superior to arrangements that direct flow from  inlet
toward outlet structure.

Monitoring Treatment After Rainfall Breaches the
Required Freeboard of a Lagoon

The authority monitoring a lagoon should specify a treatment
rate  for  the  waste water breaching the required freeboard
high  enough  to  restore  the  required  freeboard   in   a
reasonable   time  period.   If  treatment  is  delayed,  or
conducted at an unreasonably slow rate, overflow will  occur
from rains considerably below the heaviest expected rainfall
in a 10 or 25 year period.

Personnel   concerned   with  monitoring  recirculation  and
cooling water lagoons may find it prudent to define  several
stages of freeboard that relate to control of surge capacity
and to hazard of breaching the lagoons capacity:

    A.   The spillway level capacity, as established by  the
         elevation   of  the  spillway,  should  be  clearly
         defined.
                          68

-------
    B.   A crest should be provided around  the  pond  above
         the  spillway  elevation.   This  is  essential  to
         prevent breaching of the structure by  wave  action
         in  windy weather.  The height of this crest should
         be related to wind problems at the lagoon site.

    C.   A maximum  permissible  operating  level  to  avoid
         breaching  in  periods of excessive rainfall should
         be established.  This is now set by the regulation.
         Operational  experience  should  be   recorded   to
         provide   data  for  reconsideration  if  excessive
         breaching  is  noted   in   operation   under   the
         promulgated regulations.

Control of Unusual Discharges to Pond

Monitoring  authorities should require a report on all waste
water streams discharged  to  the  recirculation  and  reuse
pond.   Problems may arise at plants discharging waste water
from  processes  other  than  phosphate   manufacturing   or
fertilizer  phosphate  production.   Ponds  should  also  be
managed and located in a  manner  that  limits  ammonia  and
organic compound intrusion.

The  recirculation  and  reuse  pond  will have considerable
capacity to absorb noncontact cooling water that has  become
contaminated   by   leaks  and  process  waste  waters  from
ancillary phosphate manufacturing operations at most  sites;
however, the situation at a point source should be monitored
to  make  certain that the point source is not utilizing the
pond as a device for  evading  regulations  on  waste  water
discharges from unrelated manufacturing operations.

Many  objectionable  metals  are  kept  under control by the
sedimentation processes in the pond and by the terminal lime
treatment process.  The presence  of  ammonia  and  of  some
organic  compounds  interfere seriously with these treatment
processes.  Particular care should be  taken  around  plants
producing  ammonia and other nitrogenous fertilizers; drying
towers and  other  facilities  losing  ammonia  gas  to  the
atmosphere   are   particularly   troublesome   sources   of
contamination.    Domestic  wastes   interfere   with   metal
precipitation    processes   and   with   flocculation   and
clarification processes.

The pH range was extended from the proposed 9.0 top limit to
9.^ because of the difficulty experienced at some plants  in
meeting   the   suspended  solids,  phosphate  and  fluoride
limitations on liming to the proposed 9.C pH limit.
                         69

-------
No suspended solids  limitation  was  set  in  discharge  of
treated  contaminated  non-process  wastewater.    The  major
volume is coolinq  water  with  no  significant  content  of
supsended solids.
                         70

-------
                        SECTION VIII

         COST, ENERGY AND NON-WATER QUALITY ASPECT
General

The  costs - capital and operating - have been estimated for
the two treatment technologies  described  in  Section  VII.
These  costs are given as August 1971 dollar values.  In the
case of the costs indicated for Containment and Cooling Pond
technology, there is additional  explanation  made  on  what
they  represent  and  how  they  might  be  used.  The costs
indicated  for  the  Contaminated  (Pond)  Water   Treatment
technology  are  based on a specific treatment capacity such
as would be found at a moderate size production  unit.   The
following  paragraphs  provide  identification  of  the cost
elements used in this section and indicated on Table VIII-1.

Cost Elements

Investment

This is the capital cost associated  with  the  engineering;
site  preparation;  construction  and installation; and such
other costs required to place the technology  in  operation.
It does not include production loss or profits loss that may
be  encountered  from  tying  the  new  facilities  into the
existing plant operations.

Interest

This cost is  based  on  the  assumption  that  the  capital
expenditure was borrowed at a 7.5% annual interest rate.

Depr ec iati on

The  nature and service life expected of this type equipment
were the bases for selection of an assumed ten year straight
line depreciation.

Operating and Maintenance Costs

The items  included  in  this  cost  element  are  operating
supplies,  replacement  parts,  insurance,  taxes, operating
labor and maintenance labor.

Energy
                          71

-------
This item is the  power  costs  to  operate  the  mechanical
equipment.   Electrical  energy is assumed at the cost of 10
mils per KWH.

Total Annual Costs

An accumulation of the various cost items described above.

Installation and Operation of Technologies

Containment and Cooling Pond

The cost of this technology is difficult to estimate due  to
the  need  of  a  specific design for each individual plant.
Pond size is a function of many items  including  the  water
temperature  (cooling)  required for process, the economics of
land  availability, provision for rainfall, and geographical
location.   The  indicated  investment  cost  is   that   to
establish  a  10'  high dike around one  (1) acre.  This cost
also assumes that the dike will be established from earth at
the site and strictly by large earth-moving equipment  -  no
transportation  of  earth to the site.  Cost of earth moving
has been estimated at $1.50 per cubic yard.

It can be stated that a minimum containment and cooling pond
for a moderate size plant would be 10 - 20 acres.

Construction time is estimated at 80 hours per acre.

There would be no interruption  of  plant  operation  during
construction.

Contaminated (Pond) Water Treatment

This  is  the  same  technology and costs estimated for Pond
Water Treatment in the phosphate fertilizer section  of  the
Basic Fertilizer Chemicals Survey.

Time required for engineering, procurement, and construction
is 15 - 18 months.

There  would  be  no  interruption of plant operation during
construction.

Start-up and initial operation would  require  approximately
24  hours  of  continuous  operation to establish stabilized
conditions.

Table VIII-1  cites  1971  cost  figures  derived  from  the
oriainal  contract  study.  These figures have been expanded
                             72

-------
o o>
o 5
o
3
0" rt
M (D
H H
O H-
3 0>
CO M

rt 0
H O
(D CO
JU rt
rt
(D •
QJ M
^» t
>£»
rt O
O
rt TD
0) (D
H^ ^
O M
< 0
(D 0
H O
Oi
H vQ
|__l Ql

O M
O O
CO 3
rt co

(D rt
>Q tt
C (D
0) O>
M rt
0)
-W- QJ
M ~'
•
VO 01
O M
H"1
•o
(D O
H rt
3*
M (B
o h
0
o n
0
vQ CO
ni rt
M CO
i_j
O (D
3 iH
CO C
0)
rt M
H
n> •<»
o> o
rt i
(D ui
a o
*o
fD
h(
W
P
CO
(D
Q.
O
3

'O

(D
'O

H
O>
rt
H-
O
3

O
hh

0>

0
-

3"
H-
vQ
3*
QJ
H-

(D

0)
1-5
O


QJ

ft
3"
(D

•O
(D

H-
3
(D
3
ft
(D
hi

O
Hi

0>

O
3
(D

Oi
n

(D

(U
(D

•















































s: o
0) O
ft ^ 3
(D *T3 rt
MOO"
3 3
1-3 QJ H-
tt ^- 3
CD 0>
Oi ft
rt fl>
3 QJ
(D
3
rt
H
H
H
I
w
li>
VO
*
0
o
o
?
NJ
to
VO
0
O
H
u>
VO
vo
0



-w-
^3 O O
H 0> •
(DM.0
O> M Ul
rt o X
(D 3 M
QJ CO O
O
O
w a w
(D O 0>
M rt (D
O (D















































n n
o o
O 0> 3
M 3 rt
H- QJ 01
3 H-
vQ 3

'O (D
O 3
3 rt
Q.



1
t) M (M)
(D U) v-^
n *
VD
O1 00
O W
H







































Refer to Figure Number
for Reference

Investment





Interest on Money


Depreciation


Operating &
Maintenance Cost
Excluding Energy








Energy Cost





Total Annual
Costs



a
g
1?

n
0
w












                                                         E3

                                                         <
                                                         H
                                                         H
                                                         I—I
73

-------
                                                   TABLE VIII-2
                SUMMARIZED ESTIMATED WASTEWATER TREATMENT COSTS OF PHOSPHATE MANUFACTURING PLANTS
                                            (Costs Per Model Plant)*
Subcategory and Plant Size
Defluorinated Phosphate Rock
Medium (175,000 ton/yr)
Large (310,000 ton/yr)
Defluorinated Phosphoric Acid
Snail (193,000 ton/yr)
Large (720,000 ton/yr)
Sodium Phosphates
Average (140,000 ton/yr)

Capital Costs
77,000
100,000
574,000
1,249,000
548,000
BPCTCA
,$ O&M Costs, $
7,200
10,840
120,900
431,700
120,100
BATEA and
Capital Costs, $
155,000
220,000
(c)
	 (c)
	 (c)
NSPS W
O&M Costs, $
9,600
11,300
	 (c)
	 (c)
	 (c)
                                                                                                          (b)
(a)  Incremental  costs  after achieving BPCTCA
(b)  Does not include taxes, interest, or depreciation
(c)  No additional  costs  to  meet BATEA

 *   Derived from Reference  T.   Investment costs  are on a June,  1973  basis
    and operation  and  maintenance costs  on a November,  1973  basis.

-------
to cover the entire industry in  the  Economic  Analysis  of
Proposed  Effluent  Guidelines,  EPA,  September,  197U  and
revised  in  the  economic  analysis  study  conducted   for
promulgation.   Table  VIII-2  presents an independent study
result derived from Reference T.

No cost estimate was made for BAT practice  for  the  Sodium
Phosphates  Subcategory.   It  was the opinion of the review
committee that the BAT standards  can  be  easily  achieved.
The plant was building an expanded lagoon system for the wet
process  phosphoric  acid  plant  and  for hydrofluoric acid
manufacture.   This  lagoon  will  be  available  to  handle
difficult  streams  from  the  sodium phosphate plant.  Cost
increase from BPT to BAT should be less than five percent.

The 1.3  area  factor  originally  utilized  in  calculating
rainfall  accumulation  in  lagoons  is  no longer utilized.
This factor did not appear in the contractor's original cost
estimates.  There is no reason to include it now.  There  is
no  change  in  wastewater  flow  due  to  the change in the
guidelines.

Our contractor did not include seepage  interceptor  ditches
or  underdrainage systems for lagoons.  These costs need not
be added.  The problem is State and non-point source and not
handled by Effluent Guidelines.

Air Pollution Control

Air  pollution  control  poses  a  serious  problem  in  the
industry,  particularly  in the defluorinated phosphate rock
subcategory.  The fluoride expelled from the rock on heating
would cause an extremely  serious  air  pollution  situation
without  the  stack  scrubbing applied in the industry.  The
EPA air pollution control authorities are initiating studies
to determine the status of the air  pollution  problem,  and
the relationship to the water pollution problem.

Defluorinated phosphate rock plants and submerged combustion
defluorinated   phosphoric   plants   lose   much  water  by
evaporation, and have no normal need to discharge wastewater
from their recirculation and cooling ponds.  However, all of
these must lime treat at some place to  control  the  pH  to
prevent excessive air emission of fluoride.

Information  must  also  be  gathered  on  radon-222 and the
radioactive breakdown solid substances derived  from  radon-
222.  Radon-222 is an inert gas with a very short half life.
Exposure  of human beings to these radioactive products must
be  held  to  safe   levels.    Hopefully,   more   definite
                          75

-------
information  will soon be available on how to deal with this
problem.  The use of solid wastes, particularly gypsum,  for
home  construction is inadvisable unless found to be free of
radioactive component hazard.

Solid Wastes

Many solids residues are left as solid wastes.

The proper management of solid  wastes  resulting  from  air
pollution  control systems must be practiced.  Air pollution
control technologies generate  many  different  amounts  and
types  of  solid  wastes and liquid concentrates through the
removal of pollutants from air emissions.  These  substances
vary  greatly in their chemical and physical composition and
may be either hazardous  or  non-hazardous.   A  variety  of
techniques  may  be  employed to dispose of these substances
depending on the degree of hazard.

If thermal processing is the choice for disposal, provisions
must be made to ensure no re-entry of  the  pollutants  into
the  atmosphere.   Consideration  should  also  be  given to
recovery of materials of value in the wastes.

For those waste materials  considered  to  be  non-hazardous
where  land  disposal  is the choice for disposal, practices
similar  to  proper  sanitary  landfill  technology  may  be
followed.   The  principles  set  forth  in  the  SPA's Land
Disposal of Solid Wastes Guidelines (40 CFR 241)  may be used
as guidance for acceptable land disposal techniques.

For  those  waste  materials  considered  to  be  hazardous,
disposal  may  require  special  precautions.   In  order to
ensure  long-term  protection  of  public  health  and   the
environment,  special  preparations  and pretreatment may be
required prior to disposal.   If  land  disposal  is  to  be
practiced, these sites must not allow movement of pollutants
such  as fluoride and radium-226 to either ground or surface
water.  Sites should be selected that have natural soil  and
geological  conditions  to prevent such contamination or, if
such  conditions  do  not  exist,  artificial  means   (e.g.,
liners) should be provided to ensure long-term protection of
the    environment    from   hazardous   materials.    Where
appropriate,  the  location  of  solid  hazardous  materials
disposal   sites  should  be  permanently  recorded  in  the
appropriate office of the legal jurisdiction  in  which  the
site is located.
                          76

-------
Pretreatment

No manufacturer in these subcategories is known to discharge
wastewater    to   a   publicly   owned   treatment   plant.
Pretreatment standards have been reserved  for  the  present
time    because   of   ongoing   studies   with   incomplete
administrative decisions.
                         - 77

-------

-------
                         SECTION IX

            BEST PRACTICABLE CONTROL TECHNOLOGY
                    CURRENTLY AVAILABLE

Int.roduct.ion

The effluent limitations which must be achieved by  July  1,
1977   are   based  on  the  degree  of  effluent  reduction
attainable through the application of the  best  practicable
control   technology  currently  available.   For  the  non-
fertilizer phosphate chemicals manufacturing industry,  this
level   of   technology   is  based  on  the  best  existing
performance by exemplary plants of various sizes,  ages  and
chemical processes within each of the industry's categories.
In some cases where no truly exemplary plants were surveyed,
this level of technology is based upon state-of-the-art unit
operations commonly employed in the chemical industry.

Best practicable control technologies currently available in
the non-fertilizer phosphate chemicals industry involve both
in-process techniques and end-of-process treatment.

Based  upon the information contained in Section III through
VIII of this report, the following determinations were  made
on   the   degree   of   effluent  reduction  attainable  by
application  of  the  best  practicable  control  technology
currently  available  in  the individual process of the non-
fertilizer phosphate chemical  industry.   Each  process  is
presented separately in the following paragraphs.

Specialized Definitions

(a) Except  as  provided  below,  the  general  definitions,
abbreviations  and  methods  of analysis set forth in 40 CFR
U01 shall apply to this subpart.

    (b)  The term "process  waste  water"  means  any  water
which, during manufacturing or processing, comes into direct
contact  with  or  results from the production or use of any
raw material, intermediate product,  finished  product,  by-
product,  or  waste product.  The term "process waste water"
does not include contaminated non-process  waste  water,  as
defined below.
    (c)  The  term,  "contaminated  non-process  wastewater"
shall  mean  any water including precipitation runoff which,
during manufacturing or processing,  comes  into  incidental
contact   with   any  raw  material,  intermediate  product,
finished product, by-product or waste product  by  means  of
(1)   precipitation   runoff   (2)    accidental  spills  (3)
                         79

-------
accidental leaks caused by the failure of process  equipment
and  which  are  repaired  or  the  discharge  of pollutants
therefrom  contained  or  terminated  within  the   shortest
reasonable  time  which  shall  not  exceed  24  hours after
discovery or when  discovery  should  reasonably  have  been
made,  whichever is earliest, and (4)  discharges from safety
showers and related  personal  safety  equipment,  and  from
equipment washings for the purpose of safe entry, inspection
and  maintenance; provided that all reasonable measures have
been taken to prevent, reduce, eliminate and control to  the
maximum  extent  feasible  such contact and provided further
that all reasonable  measures  have  been  taken  that  will
mitigate the effects of such contact once it has occurred.
     (d)  The term "ten year 24 hour  rainfall  event"  shall
mean   the  maximum  precipitation  event  with  a  probable
recurrence interval of once in 10 years as  defined  by  the
National   Weather   Service  in  technical  paper  no.  40,
"Rainfall Frequency Atlas of the United States," May,  1961,
and  subsequent  amendments  or equivalent regional or State
rainfall probability information developed therefrom.
     (e)  The term "25 year 24  hour  rainfall  event"  shall
mean   the  maximum  precipitation  event  with  a  probable
recurrence interval of once in 25 years as  defined  by  the
National   weather   Service  in  technical  paper  no.  40,
"Rainfall Frequency Atlas of the United States," May,  1961,
and  subsequent  amendments  or equivalent regional or State
rainfall probability information developed therefrom.

(a), above, applies to all three  subcategories;   (b),   (c),
(d)  and   (e)   apply to the defluoririated phosphate rock and
the defluorinated phosphoric acid subcategories.

    Subpart D - Defluorinated Phosphate Rock Subcategory

The provisions of this subpart are applicable to  discharges
resulting  from  the  defluorination  of  phosphate  rock by
application of high temperature  treatment  along  with  wet
process phosphoric acid, silica and other reagents.

In  establishing  the limitations set forth in this section,
EPA took  into  account  all  information  it  was  able  to
collect,  develop  and solicit with respect to factors (such
as age and  size  of  plant,  raw  materials,  manufacturing
processes,    products    produced,   treatment   technology
available, energy requirements and costs) which  can  affect
the    industry   subcategorization   and   effluent   levels
established.  It is, however, possible that data which would
affect these limitations have not been available and,  as   a
result,  these  limitations  should  be adjusted for certain
plants in this industry.  An individual discharger or  other
                          80

-------
interested  person  may  submit  evidence  to  the  Regional
Administrator (or  to  the  State,  if  the  State  has  the
authority  to  issue NPDES permits) that factors relating to
the equipment or facilities involved, the  process  applied,
or  other  such  factors  related  to  such  discharger  are
fundamentally different from the factors considered  in  the
establishment  of  the  guidelines.   On  the  basis of such
evidence  or  other  available  information,  the   Regional
Administrator  (or  the  State)  will make a written finding
that such factors are or are not fundamentally different for
that facility compared to those specified in the Development
Document.  If such fundamentally different factors are found
to exist, the Regional  Administrator  or  the  State  shall
establish  for  the  discharger  effluent limitations in the
NPDES  permit  either  more  or  less  stringent  than   the
limitations  established  herein,  to the extent dictated by
such fundamentally different factors.  Such limitations must
be  approved  by  the  Administrator  of  the  Environmental
Protection   Agency.    The  Administrator  may  approve  or
disapprove such limitations, specify other  limitations,  or
initiate proceedings to revise these regulations.

The  following limitations establish the quantity or quality
of  pollutants  or  pollutant  properties,  which   may   be
discharged  by  a  point source subject to the provisions of
this subpart  after  application  of  the  best  practicable
control technology currently available.

    (a)  Subject to the provisions of  paragraphs   (b) ,   (c)
and (d) below:
    The  following  limitations  establish  the  quantity or
quality of pollutants or pollutant properties, controlled by
this section, which may be  discharged  by  a  point  source
subject  to the provisions of this subpart after application
of  the  best  practicable  control   technology   currently
available: there shall be no discharge of process wastewater
pollutants to navigable waters.
    (b)  Process waste water pollutants from a cooling water
recirculation system designed, constructed and  operated  to
maintain  a  surge capacity equal to the runoff from the 10-
year,  24-hour  rainfall  event  may  be  discharged,  after
treatment  to  the  standards  set forth in subparagraph  (c)
below, whenever chornic or catastrophic precipitation events
cause the water level in the pond to  rise  into  the  surge
capacity.    Process   waste   water  must  be  treated  and
discharged whenever the water level equals  or  exceeds  the
mid point of the surge capacity.
    (c)  The  concentration  of  pollutants  discharged   in
process  wastewater pursuant to the limitations of paragraph
                           81

-------
 (b) shall not exceed the  values  listed  in  the  following
 table:

                                     Average of Daily
                                     Values for 30
Effluent              Maximum for    Consecutive Days
Character!stic        Any 1 Day      Shall Not Exceed
                                 mg/1

Total Phosphorus(P)       105                 35
Fluoride                  75                 25
TSS                      150                 50
pH                         Within the range 6.0 to 9.5

The  total  suspended  solid  limitation  set  forth in this
paragraph shall be waived  for  process  wastewater  from  a
calcium  sulfate  storage  pile  runoff  facility,  operated
separately or in  combination  with  a  water  recirculation
system,  which  is  chemically treated and then clarified or
settled to meet the other pollutant limitations set forth in
this paragraph.

    (d)  The  concentration  of  pollutants  discharged   in
contaminated  non-process  wastewater  shall  not exceed the
values listed in the following table:

                                     Average of Daily
                                     Values for 30
Effluent              Maximum for    Consecutive Days
Characteristic        Any 1 Day      Shall Not Exceed
                                 mg/1

Total Phosphorus(P)       105                 35
Fluoride                  75          .      25
pH                         Within the range 6.C to 9.5

Rationale for Best Practicable Control Technology
Currently Available

The criteria  used  for  selection  of  the  technology  was
information  obtained  at  three of the four total operating
plants in the U.S.  Two of the three plants (survey plants A
and B) have the Containment and Cooling Pond  Technology  in
service  and  to date have never found it necessary to treat
or discharge water to  navigable  waters.   Survey  Plant  C
stated  plans  of  installing  this  technology  in the near
future.

The proposed limitations are based on composite   (not  grab)
sampling  and  years  of  historical  effluent  data.  These
                           82

-------
limitations represent values which are being achieved by the
better exemplary plants surveyed.

The volume of process waste water that may be discharged  is
determined  by the rainfall-evaporation circumstances at the
site, and by the definitions and regulations  pertaining  to
the  structure of the recirculation and reuse pond.  Process
waste water  discharge  is  not  necessary  at  some  sites.
Plants  that  discharge process waste water normally do this
only in periods of heavy rainfall.

Discharged  effluent  must  be  lime  treated.   This  is  a
relatively  costly  operation.   Diligent water conservation
and reuse practices have proven to be  the  most  economical
means to handle the waste water problem.
   Subpart E - Defluorinated Phosphoric Acid Subcategory

The  provisions of this subpart are applicable to discharges
resulting from the defluorination of phosphoric  acid.   Wet
process phosphoric acid is dehydrated by application of heat
and  other processing aids such as vacuum and air stripping.
The acid is concentrated up to 70-73  percent  P.2O5  in  the
defluorination process.

The  technology described as Containment and Cooling Pond is
defined as the best practicable control technology currently
available.   This  technology  confines  all  process  waste
waters   to   the   plant   area.   Recirculation  of  these
contaminated process waters to  the  process  together  with
good  water  management  practices essentially eliminate the
need for treatment  or  discharge  of  treated  contaminated
process  water  to navigable waters.  In the event of a need
for emergency type discharge, then the  Contaminated  (Pond)
Water  treatment  technology or a facsimile of it would also
be indicated.

    The following  limitations  establish  the  quantity  or
quality  of pollutants or pollutant properties, which may be
discharged by a point source subject to  the  provisions  of
this  subpart  after  application  of  the  best practicable
control technology currently available:

    (a)  Subject to the provisions of  paragraphs  (b) ,  (c)
and (d) below:
    The  following  limitations  establish  the  quantity or
quality of pollutants or pollutant properties, controlled by
this section, which may be  discharged  by  a  point  source
subject  to the provisions of this subpart after application
                             83

-------
of  the  best  practicable  control   technology   currently
available: there shall be no discharge of process wastewater
pollutants to navigable waters.
    (b)  Process waste water pollutants from a cooling water
recirculation system designed, constructed and  operated  to
maintain  a  surge capacity equal to the runoff from the 10-
year,   24-hour  rainfall  event  may  be  discharged,  after
treatment  to  the  standards  set forth in subparagraph (c)
below, whenever chornic or catastrophic precipitation events
cause the water level in the pond to  rise  into  the  surge
capacity.    Process   waste   water  must  be  treated . and
discharged whenever the water level equals  or  exceeds  the
mid point of the surge capacity.
    (c)  The  concentration  of  pollutants  discharged   in
process  wastewater pursuant to the limitations of paragraph
(b)  shall not exceed the  values  listed  in  the  following
table:

                                     Average of Daily
                                     Values for 30
Effluent              Maximum for    Consecutive Days
Characteri stic        Any 1 Day      Shall Not Exceed
                                 mg/1

Total Phosphorus(P)       105                 35
Fluoride                  75                 25
TSS                      150                 50
pH                         Within the range 6.0 to 9.5

The  total  suspended  solid  limitation  set  forth in this
paragraph shall be waived  for  process  wastewater  from  a
calcium  sulfate  storage  pile  runoff  facility,  operated
separately or in  combination  with  a  water  recirculation
system,  which  is  chemically treated and then clarified or
settled to meet the other pollutant limitations set forth in
this paragraph.

    (d)  The  concentration  of  pollutants  discharged   in
contaminated  non-process  wastewater  shall  not exceed the
values listed in the following table:

                                     Average of Daily
                                     Values for 30
Effluent              Maximum for    Consecutive Days
Characteristic        Any 1 Day      Shall Not Exceed
                                 mg/1

Total Phosphorus(P)       105                 35
Fluoride                  75                 25
pH                         Within the range 6.0 to 9.5
                              84

-------
Rationale for Best Practicable Control Technology
Currently Available

The criteria  used  for  selection  of  the  technology  was
information  obtained  at  three of the four total operating
plants in the U.S.  Two of the three plants  (survey plants A
and B) have the Containment and Cooling Pond  Technology  in
service  and  to date have never found it necessary to treat
or discharge water to  navigable  waters.   Survey  Plant  C
stated  plans  of  installing  this  technology  in the near
future.

The proposed limitations are based on composite  (not  grab)
sampling  and  years  of  historical  effluent  data.  These
limitations represent values which are being achieved by the
better exemplary plants surveyed.

The volume of process waste water that may be discharged  is
determined  by the rainfall-evaporation circumstances at the
site, and by the definitions and regulations  pertaining  to
the  structure of the recirculation and reuse pond.  Process
waste water  discharge  is  not  necessary  at  some  sites.
Plants  that  discharge process waste water normally do this
only in periods of heavy rainfall.

Discharged  effluent  must  be  lime  treated.   This  is  a
relatively  costly  operation.   Diligent water conservation
and reuse practices have proven to be  the  most  economical
means to handle the waste water problem.

         Subpart F - Sodium Phosphates Subcategory

The  provisions of this subpart are applicable to discharges
resulting from the manufacture of purified sodium phosphates
from wet process phosphoric acid.

The  technology  described  as  Contaminated  (Pond)    Water
Treatment   is  defined  as  the  best  practicable  control
technology currently available, and/or in-process technology
- whichever will achieve the same  results.   Process  waste
water   is  also  continuously  treated  and  discharged  to
navigable waters.  A lagoon recirculation system is  in  use
for  treatment of the process waste water from production of
the  raw  product  acid  required  for   sodium   phosphates
manufacture, and can be utilized for disposal of troublesome
waste water streams.

    The  following  limitations  establish  the  quantity or
quality of pollutants or pollutant properties, controlled by
this section, which may be  discharged  by  a  point  source
                            85

-------
subject  to the provisions of this subpart after application
of  the  best  practicable  control   technology   currently
available:

Effluent                         Effluent
Char a ct er i st i c                   Limitations

                    Maximum for     Average of daily
                    any one day     values for thirty
                                    consecutive days
                    	     shall not exceed

          (Metric units, kg/kkg of product)
          (English units, lb/1000 Ib of product)

TSS                     0.50             0.25
Total phosphorus        0.80             0.40
  (as P)
Fluoride                0.30             0.15
pH                      Within the range 6.0 to 9.5.
Rationale for Best Practicable Control Technology
Currently Available

The  criteria used for selection of the treatment technology
included a variety of items ranging  from  consideration  of
the  process  characteristics to the known commercial limits
of capability.

In this process, the conditions are such  that  contaminated
process  water  cannot  be  re-used  or  treated  due to the
product  purity  specifications  and  the  unit   operations
required  to attain that purity.  Therefore, fresh water use
is a process requirement and continuous discharge of process
water is a necessity.   Based  on  this  consideration,  the
capability  of  treating  the  contaminated process water to
achieve significant reduction of contaminants to  acceptable
levels  has  been commercially proven.  The recognition that
this end-of-process treatment is sensitive to water quantity
variations with subsequent adverse quality effects indicated
the need to base limitations on  production  tonnage  rather
than the best possible treatment results and concentrations.
Six  different  process areas contribute to the contaminated
process water stream and process water effluent quantity  is
a   function   of  the  number  of  units  in  instantaneous
operation.

Another  consideration  was  that  the  proposed  guidelines
coincide   with   commercial  operations  for  reduction  of
                             86

-------
parameters within limits that would not  initiate  the  need
for   additional   treatment   facilities.    That  is,  the
guidelines  proposed  coincide   with   contaminant   levels
attainable  at  the  proposed pH 6.0 to 9.5 treatment range.
This  pH  range  permits  direct  discharge   of   clarified
effluent,  without  neutralization.   All waste streams that
bear any of the dehydrated products,  metaphosphate  through
polyphosphate,  can  be  diverted  to the recirculation pond
when  flow  to  the  clarifier  is  sufficient  to  cause  a
discharge   violation.   These  modified  phosphates  create
problems in the usual clarification process.  The  treatment
system  will  require  a  hydrolytic  process  that converts
phosphate  components  to   the   orthophosphate   form   if
significant   quantities   of   polyphosphate   waste  water
components are in the stream undergoing  lime  precipitation
and clarification.  These processes are discussed in Section
VII.
                            87

-------

-------
                         SECTION X
     BEST AVAILABLE TECHNOLOGY ECONOMICALLY ACHIEVABLE

The  effluent  limitations which must be achieved by July 1,
1983,  are  based  on  the  degree  of  effluent   reduction
attainable   through   application  of  the  best  available
technology   economically   achievable.    This   level   of
technology  was based on the very best control and treatment
technology employed by a specific point  source  within  the
industrial  category  and  on sound, established waste water
management and treatment processes.

Specialized  definitions  are  the  same  as  for  the  best
practicable  control  technology  currently available except
that the surge capacity must hold the  heaviest  25-year-24-
hour rainfall instead of the 10-year event rainfall.

    Subpart D - Defluorinated Phosphate Rock Subcategory

    The  following  limitations  establish  the  quantity or
quality of pollutants or pollutant properties, which may  be
discharged  by  a  point source subject to the provisions of
this  subpart  after  application  of  the  best   available
technology economically achievable:
     (a)  Subject to the provisions of  paragraphs   (b) ,  (c)
and  (d) below:
    The  following  limitations  establish  the  quantity or
quality of pollutants or pollutant properties, controlled by
this section, which may be  discharged  by  a  point  source
subject  to the provisions of this subpart after application
of the best available  technology  economically  achievable:
there shall be no discharge of process wastewater pollutants
to navigable waters.
     (b)  Process waste water pollutants from a cooling water
recirculation system designed, constructed and  operated  to
maintain  a  surge capacity equal to the runoff from the 25-
year,  24-hour  rainfall  event  may  be  discharged,  after
treatment  to  the  standards  set forth in subparagraph (c)
below, whenever chronic or catastrophic precipitation events
cause the water level in the pond to  rise  into  the  surge
capacity.    Process   waste   water  must  be  treated  and
discharged whenever the water level equals  or  exceeds  the
mid point of the surge capacity.
     (c)  The  concentration  of  pollutants  discharged   in
process  wastewater pursuant to the limitations of paragraph
 (b) shall not exceed the  values  listed  in  the  following
table:
                           89

-------
                                     Average of Daily
                                     Values for 30
Effluent              Maximum for    Consecutive Days
Characteristic        Any 1 Day      Shall Not Exceed
                                 mg/1

Total Phosphorus(P)       105                 35
Fluoride                  75                 25
TSS                      150                 50
pH                         Within the range 6.0 to 9.5

The  total  suspended  solid  limitation  set  forth in this
paragraph shall be waived  for  process  wastewater  from  a
calcium  sulfate  storage  pile  runoff  facility,  operated
separately or in  combination  with  a  water  recirculation
system,  which  is  chemically treated and then clarified or
settled to meet the other pollutant limitations set forth in
this paragraph.

    (d)  The  concentration  of  pollutants  discharged   in
contaminated  non-process  wastewater  shall  not exceed the
values listed in the following table:

                                     Average of Daily
                                     Values for 30
Effluent              Maximum for    Consecutive Days
Characteristic        Any 1 Day      Shall Not Exceed
                                 mg/1

Total Phosphorus(P)       105                 35
Fluoride                  75                 25
pH                         Within the range 6.0 to 9.5

Rationale for the Best Available Technology Economically
Achievable

The rationale is identical  to  that  for  best  practicable
control   technology  currently  available,  except  that  a
greater freeboard  is  required  for  retention  of  heavier
rains.   The  required  technology to achieve BATEA has been
established at exemplary plants.

   Subpart E - Defluorinated Phosphoric Acid Subcategory

    The following  limitations  establish  the  quantity  or
quality  of pollutants or pollutant properties, which may be
discharged by a point source subject to  the  provisions  of
this   subpart  after  application  of  the  best  available
technology economically achievable:
                           90

-------
    (a)  Subject to the provisions of  paragraphs   (b) ,   (c)
and (d) below:
    The  following  limitations  establish  the  quantity or
quality of pollutants or' pollutant properties, controlled by
this section, which may be  discharged  by  a  point  source
subject  to the provisions of this subpart after application
of the best available  technology  economically  achievable:
there shall be no discharge of process wastewater pollutants
to navigable waters.
    (b)  Process waste water pollutants from a cooling water
recirculation system designed, constructed and  operated  to
maintain  a  surge capacity equal to the runoff from the 25-
year,   24-hour  rainfall  event  may  be  discharged,  after
treatment  to  the  standards  set forth in subparagraph  (c)
below, whenever chronic or catastrophic precipitation events
cause the water level in the pond to  rise  into  the  surge
capacity.    Process   waste   water  must  be  treated  and
discharged whenever the water level equals  or  exceeds  the
mid point of the surge capacity.
    (c)  The  concentration  of  pollutants  discharged   in
process  wastewater pursuant to the limitations of paragraph
(b)  shall not exceed the  values  listed  in  the  following
table:

                                     Average of Daily
                                     Values for 30
Effluent              Maximum for    Consecutive Days
Characteristic        Any 1 Day      Shall Not Exceed
             r                    mg/1

Total Phosphorus (P)      105                 35
Fluoride                  75                 25
TSS                      150                 50
pH                         Within the range 6.0 to 9.5

The  total  suspended  solid  limitation  set  forth in this
paragraph shall be waived  for  process  wastewater  from  a
calcium  sulfate  storage  pile  runoff  facility,  operated
separately or in  combination  with  a  water  recirculation
system,  which  is  chemically treated and then clarified or
settled to meet the other pollutant limitations set forth in
this paragraph.

    (d)  The  concentration  of  pollutants  discharged   in
contaminated  non-process  wastewater  shall  not exceed the
values listed in the following table:

                                     Average of Daily
                                     Values for 30
Effluent              Maximum for    Consecutive Days
                             91

-------
Characteristic        Any 1 Day      Shall Not Exceed
                                 mg/1

Total Phosphorus (P)       105                 35
Fluoride                  75                 25
pH                         Within the range 6.0 to 9.5

The rationale is identical to that for BPCTCA except that  a
greater  freeboard  is  required  for  retention  of heavier
rains.  The required  technology  has  been  established  at
exemplary plants.

         Subpart F - Sodium Phosphates Subcategory

The   best   available   treatment  economically  achievable
includes  the  use  of  the  contaminated  water  pond   and
continuous lime treatment of some waste water streams.

The   best   available   treatment  economically  achievable
standards for the sodium phosphates subcategory are  set  at
70  percent  of  the  discharge levels for suspended solids,
fluoride and phosphate waste water components  proposed  for
the best practicable control technology currently available.
It  is  the  opinion  of the Environmental Protection Agency
staff and its advisors that this reduction  can  be  readily
achieved.  Improvements of this order and greater are common
in  fertilizer phosphate plants facing the need for improved
water conservation practices to avoid excessive costly  lime
treatment.   The recirculation lagoon is available to handle
waste streams that present difficult treatment problems.

    The following  limitations  establish  the  quantity  or
quality of pollutants or pollutant properties, controlled by
this  section,  which  may  be  discharged by a point source
subject to the provisions of this subpart after  application
of the best available technology economically achievable:

Effluent                         Effluent
Characteristic                   Limitations

                    Maximum for     Average of daily
                    any one day     values for thirty
                                    consecutive days
                    	     shall not exceed

          (Metric units, kg/kkg or lb/1000 Ib of product)

TSS                     0.35             0.18
Total phosphorus        0.56             0.28
   (as P)
Fluoride                0.21             0.11
pH                      Within the range 6.0 to 9.5.
                          92

-------
                         SECTION XI
              NEW SOURCE PERFORMANCE STANDARDS
                 AND PRETREATMENT STANDARDS
New Source Performance Standards

This  level  of technology is to be achieved by new sources.
The term "new source" is defined in the  Act  to  mean  "any
source,   the  construction  of  which  is  commenced  after
publication of proposed regulations prescribing  a  standard
of  performance." New source performance standards are to be
evaluated by adding  to  the  consideration  underlying  the
identification   of   best  practicable  control  technology
currently available, a determination of what  higher  levels
of  pollution  control  are  available  through  the  use of
improved production processes and/or  treatment  techniques.
Thus,  in addition to considering the best in-plant and end-
of-process  control  technology,  new   source   performance
standards  are to be based upon an analysis of how the level
of effluent  may  be  reduced  by  changing  the  production
process itself.  Alternative processes, operating methods or
other  alternatives  are to be considered.  However, the end
result of the analysis identifies effluent  standards  which
would  reflect  levels of control achievable through the use
of  improved  production  processes   (as  well  as   control
technology),  rather  than  prescribing a particular type of
process or technology which must  be  employed.   A  further
determination   which   was   to  be  made  for  new  source
performance standards is whether a  standard  permitting  no
discharge of pollutants is practicable.

The  following factors were to be considered with respect to
production processes which were analyzed  in  assessing  new
source performance standards:

    a.   The type of process employed and process changes.

    b.   Operating methods.

    c.   Batch as opposed to continuous operations.

    d.   Use of alternative raw materials and mixes  of  raw
         materials.

    e.   Use of dry rather  than  wet  processes   (including
         substitution of recoverable solvents for water).
                            93

-------
    f.   Recovery of pollutants as by-products.

    Subpart D - Defluorinated Phosphate Rock Subcategory

    The  following  effluent   limitations   establish   the
quantity  or  quality of pollutants or pollutant properties,
which may be discharged by a point  source  subject  to  the
provisions   of   this  subpart  after  application  of  the
standards of performance for new sources.
    (a)  Subject to the provisions of  paragraphs  (b) ,  (c)
and (d) below:
    The  following  limitations  establish  the  quantity or
quality of pollutants or pollutant properties, controlled by
this section, which may be  discharged  by  a  point  source
subject  to the provisions of this subpart after application
of new source  performance  standards:  there  shall  be  no
discharge  of  process  wastewater  pollutants  to navigable
waters.
    (b)  Process waste water pollutants from a cooling water
recirculation system designed, constructed and  operated  to
maintain  a  surge capacity equal to the runoff from the 25-
year,   24-hour  rainfall  event  may  be  discharged,  after
treatment  to  the  standards  set forth in subparagraph (c)
below, whenever chronic or catastrophic precipitation events
cause the water level in the pond to  rise  into  the  surge
capacity.    Process   waste   water  must  be  treated  and
discharged whenever the water level equals  or  exceeds  the
mid point of the surge capacity.
    (c)  The  concentration  of  pollutants  discharged   in
process  wastewater pursuant to the limitations of paragraph
(b) shall not exceed the  values  listed  in  the  following
table:

                                     Average of Daily
                                     Values for 30
Effluent              Maximum for    Consecutive Days
Characteristic        Any 1 Day      ShallNot Exceed
                                 mg/1

Total Phosphorus(P)      105                 35
Fluoride                  75                 25
TSS                      150                 50
pH                         Within the range 6.0 to 9.5

The  total  suspended  solid  limitation  set  forth in this
paragraph shall be waived  for  process  wastewater  from  a
calcium  sulfate  storage  pile  runoff  facility,  operated
separately or in  combination  with  a  water  recirculation
system,  which  is  chemically treated and then clarified or
                            94

-------
settled to meet the other pollutant limitations set forth in
this paragraph.

    (d)  The  concentration  of  pollutants  discharged   in
contaminated  non-process  wastewater  shall  not exceed the
values listed in the following table:

                                     Average of Daily
                                     Values for 30
Effluent              Maximum for    Consecutive Days
Characteristic        Any 1 Day      Shall Not Exceed
                                 mg/1

Total Phosphorus (P)       105                 35
Fluoride                  75                 25
pH                         Within the range 6.0 to 9.5

   Subpart E - Defluorinated Phosphoric Acid Subcategory

    The following limitations and guidelines  establish  the
quantity  or  quality of pollutants or pollutant properties,
which may be discharged by a point  source  subject  to  the
provisions   of   this  subpart  after  application  of  the
standards of performance for new sources:
    (a)  Subject to the provisions of  paragraphs  (b),  (c)
and (d) below:
    The  following  limitations  establish  the  quantity or
quality of pollutants or pollutant properties, controlled by
this section, which may be  discharged  by  a  point  source
subject  to the provisions of this subpart after application
of the standards of performance for new sources: there shall
be  no  discharge  of  process  wastewater   pollutants   to
navigable waters.
    (b)  Process waste water pollutants from a cooling water
recirculation system designed, constructed and  operated  to
maintain  a  surge capacity equal to the runoff from the 25-
year,   24-hour  rainfall  event  may  be  discharged,  after
treatment  to  the  standards  set forth in subparagraph (c)
below, whenever chronic or catastrophic precipitation events
cause the water level in the pond to  rise  into  the  surge
capacity.    Process   waste   water  must  be  treated  and
discharged whenever the water level equals  or  exceeds  the
mid point of the surge capacity.
    (c)  The  concentration  of  pollutants  discharged   in
process  wastewater pursuant to the limitations of paragraph
(b)  shall not exceed the  values  listed  in  the  following
table:

                                     Average of Daily
                                     Values for 30
                             95

-------
Effluent              Maximum for    Consecutive Days
Character!stic        Any 1 Day      Shall Not Exceed
                                 mg/1

Total Phosphorus(P)       105                 35
Fluoride                  75                 25
TSS                      150                 50
pH                         Within the range 6.0 to 9.5

The  total  suspended  solid  limitation  set  forth in this
paragraph shall be waived  for  process  wastewater  from  a
calcium  sulfate  storage  pile  runoff  facility,  operated
separately or in  combination  with  a  water  recirculation
system,  which  is  chemically treated and then clarified or
settled to meet the other pollutant limitations set forth in
this paragraph.

     (d)  The  concentration  of  pollutants  discharged   in
contaminated  non-process  wastewater  shall  not exceed the
values listed in the following table:

                                     Average of Daily
                                     Values for 30
Effluent              Maximum for    Consecutive Days
Cbaracteri s t i c        Any 1 Day      Shall Not Exceed
                                 mg/1

Total Phosphorus(P)       105                 35
Fluoride                  75                 25
pH                         Within the range 6.0 to 9.5

         Subpart F - Sodium Phosphates Subcategory

Performance standards for new sources are the  same  as  for
best available technology economically achievable:

The   following   standards  of  performance  establish  the
quantity or guality of pollutants or  pollutant  properties,
controlled by this section, which may be discharged by a new
source subject to the provisions of this subpart:

Pollutant or                     Effluent
Pollutant Property               Limitations

                    Maximum for     Average of daily
                    any one day     values for thirty
                                    consecutive days
                    	     shall not exceed

          (Metric units, kg/kkg of product)
                             96

-------
         (English units, lb/1000 Ib of product)

TSS                      0.35              0.18
Total phosphorus         0.56              0.28
  (as P)
Fluoride                 0.21              0.11
pH                       Within the range 6.0 to 9.5

Pretreatment Standards for Existing and New Sources

All pretreatment standards are reserved for the present time
because  of  ongoing  studies  and incomplete administrative
decisions.
                               97

-------

-------
                        SECTION XII

                       AC KNOWL EDGMENT
This report was prepared  by  the  Environmental  Protection
Agency  on  the  basis of a comprehensive study performed by
Davy Powergas, Inc., under contract  no.  68-01-1508,  model
#2.  Mr. R. W. Heinz, Project Manager, prepared the original
(contractor's)  report.   Mr.  Heinz  was  assisted  in  the
preparation of this report, by the following personnel:  Mr.
D. W. Ross, Mr. Charles T. Harding, Mr.  Gerald  T.  Fields,
Mr.  N.  V. Fry, Mr. George Telatnik, Mr. Jack Frost, Mr. E.
Singler, and Mr. H. Honey.

This study was initiated under the supervision and  guidance
of  Elwood  E.  Martin.   The final phases of the study were
supervised by Chester E. Rhines, with  extensive  transition
assistance from Mr. Martin.

Overall  guidance  and  excellent assistance was provided by
the author's associates in the Effluent Guidelines Division,
particularly Messrs. Allen Cywin, Director, Ernst  P.  Hall,
Deputy Director, and Walter J. Hunt, Branch Chief.

The  cooperation  of  manufacturers who offered their plants
for survey and  contributed  pertinent  data  is  greatfully
appreciated.  The operations and the plants visited were the
property of the following companies:

         Borden Chemical Company, Plant City, Fla.

         Occidental Chemical Co., Houston, Tex.

         Olin Corporation, Stamford, Conn.

         J. R. Simplot Co., Pocatello, Idaho

         Thornton Laboratory, Tampa, Fla.

The  members  of  the  working  group/steering committee who
participated in the internal EPA review are:

         Mr. Walter J. Hunt, Chairman, Effluent Guidelines
                   Di vi si on

         Dr. Chester E. Rhines, Project Officer,
                   Effluent Guidelines Division

         Mr. Elwood Martin, Effluent Guidelines Division
                              99

-------
         Mr. Lamar Miller, Effluent Guidelines Division

         Dr. Robert Swank, NERC, Corvallis (Athens)

         Mr. Paul Desrosiers, ORM, Headquarters

         Mr. Louis W. DuPuis, Economic Analysis Section

         Dr. Edmund Lomasney, Region IV

         Mr. James Rouse, NFIC, Denver

Acknowledgement and appreciation is also given to  Ms.  Kaye
Starr,  Ms.  Nancy  Zrubek,  Ms.  Brenda  Holmone, Ms. Alice
Thompson,  and  Ms.  Ernestine  Christian  of  the  Effluent
Guidelines Division secretarial staff and to the secretarial
staff  of  Davy  Powergas,  Inc.,  for  their efforts in the
typing  of  drafts,  necessary  revisions,  and  the   final
preparation of this and the contractor's draft document. .
                             100

-------
                        SECTION XIII

                         REFERENCES


A.  Phosphoric Acid, Phosphates and  Phosphatic  Fertilizers
    by  William Henry Waggaman, University Microfilms, Inc.,
    Ann Arbor, PP. 233-236, original volume copyright  1927,
    1952,  by  Reinhold  Publishing  Corporation, Library of
    Congress Card Number 52-9791.

B.  Defluorination  of  Phosphate   Rock   by   Clinton   A.
    Hollingsworth,  Lakeland,  Florida,  assignor  to Smith-
    Douglas  Company,  Inc.,  Norfolk,  Va.,  United  States
    Patent Office Number 2,995,137, Patented Aug. 8, 1961.

C.  Method of Def luorinatinq Phosphate Rock in a.  Fluid  Bed
    Reactor  by Clinton A. Hollingsworth and John H. Snyder,
    Lakeland, Fla., assignors to  the  Borden  Company,  New
    York,  N.Y.,  a corporation of New Jersey, United States
    Patent Office Number  3,364,008,  Patented  January  16,
    1968.

D.  Method of Agglomerating Phosphate Material by Clinton A.
    Hollingsworth  and  Jack  F.  Lewis,   Lakeland,   Fla.,
    assignors,  by mesne assignments, to The Borden Company,
    United States Patent Office, Number 3,189,433,  Patented
    June 15, 1965.

E.  Chemical   Economics   Handbook,    Stanford    Research
    Institute,   Phosphorus   and   Compounds,  762.2030  A,
    762.2030 B, 762.2030 C, December 1969.

F.  Phosphorus  and  Its  Compounds,  John  R.  Van   Wager,
    Interscience  Publishers, Inc., New York  (1961)   Library
    of congress Card No. 58-10100.

G.  1972  Fertilizer  Summary  Data,  Norman   L.   Hargett,
    National Fertilizer Development Center, Tennessee Valley
    Authority, Muscle Shoals, Alabama.

H.  Development Document for Effluent Limitations Guidelines
    and New Source Performance Standards for the  Phosphorus
    Derived Chemicals Segment of the Phosphate Manufacturing
    Point   Source  Category,  United  States  Enivronmental
    Protection Agency, EPA 440/1-74/006, January, 1974.

I.  Development Document for Effluent Limitations Guidelines
    and New  Source  Performance  Standards  for  the  Basic
    Fertilizer  Manufacturing  Point Source Category, United
                          101

-------
    States Environmental Protection Agency, EPA 440/174-011-
    a, March, 1974.

J.  Engineering Field  Manual  for  Conservation  Practices,
    U.S.   Department   of  Agriculture,  Soil  conservation
    Service Section I, 1969 and Section 2, 1971.

K-  Earth Manual, U.S. Department of the Interior, Bureau of
    Reclamation, First Edition, Denver, Colorado, July, 1940
    (a new edition is being printed).

k«  Design of Small Dams, U.S. Department of  the  Interior,
    Bureau of Reclamation, Second Edition, 1973.

M.  Those Nasty Phosphatic Clay Ponds, Environmental Science
    and Technology, page 312, April, 1974.

N.  Reconnaissance Study  of  Radiochemical  Pollution  from
    Phosphate   Rock  Mining  and  Milling,  National  Field
    Investigations Center-Denver, Denver, Colorado,  Revised
    May, 1974.

O.  Interim  Radium-226  Effluent  Guidance  for   Phosphate
    Chemicals   and   Phosphate   Fertilizer  Manufacturing,
    Statement of Considerations - August 5,  1974,  Criteria
    and  Standards  Division,  Office of Radiation Programs,
    Environmental  Protection   Agency,   Washington,   D.C.
    20460.

P.  Black & Veatch,  Consulting  Engineers,  Process  Design
    Manual   for   Phosphorus  Removal,  U.S.  Environmental
    Protection Agency Program 17010 GNP, Contract  14-12-936
    (October 1971) .

Q.  "Water  Quality  Criteria  1972,"  National  Academy  of
    Sciences  and  National  Academy  of Engineering for the
    Environmental  Protection Agency, Washington, D.C.   1972
    (U.S. Govt. Printing Office  Stock No. 5501-00520).

R.  R.E. Kirk and  D.F.  Othmer,  Encyclopedia  of  Chemical
    Technology, Interscience, N.Y., 1966.

S.  EPA Report, Suspect Carcinogens in  Water  Supplies,  by
    Office of R S  D, April,  1975.

T.  Final Report on "Cost of Implementation and Capabilities
    of Available Technology to Comply  with  P.L.  92-50C",
    Industry   Category   18,  Phosphate  Manufacturing  for
    National  Commission  on  Water  Quality,  R.A.   Ewing,
                        102

-------
    Battelle's  Columbus  Laboratories  with assistance from
    Burgess & Niple, Ltd., July 3, 1975.

U.  Technical Note ORP/CSD-75-3  Radioactivity  Distribution
    in   Phosphate  Products,  By-Products,  Effluents,  and
    Wastes, The U.S.  EPA,  Office  of  Radiation  Programs,
    August, 1975.

V.  Technical Note, ORP/CSD-75-4 Preliminary Findings, Radon
    Daughter Levels in Structures Constructed  on  Reclaimed
    Florida  Phosphate  Land,  U.S. EPA, Office of Radiation
    Programs, September,  1975.
                          103

-------

-------
                        SECTION XIV
                          GLOSSARY
Apatite

A natural  calcium  phosphate  usually  containing  fluorine
occurring as phosphate rock.

PPG

Davy Powergas

Gyp-pond

This  term  is widely used at fertilizer phosphate plants to
indicate the pond receiving waste  water  and . acting  as  a
recirculation,  cooling  and  water reuse pond.  Many plants
have ponds with a variety of functions such as receiving the
calcium  sulfate  residue  from  acid  treatment  of   rock,
receiving   calcium   fluoride  from  first  stage  of  lime
precipitation,  receiving  calcium  phosphate  and   calcium
fluoride  sediment  from second stage of lime precipitation,
recirculation of stack washing and tail gas  scrubber  water
and   simultaneously   removing   heat   and  sediment,  and
deposition of troublesome solids, as arsenic sulfide.  Local
authorities will have to determine  specific  pond  uses  in
order   to  establish  essential  solid  waste  control  and
groundwater pollution control measures.

kkg

1,000 kilograms

1

liter

Process Waste Water

The term "process waste water" means any water which, during
manufacturing or processing, comes into direct contact  with
or  results  from the production or use of any raw material,
intermediate product, finished product, by-product, or waste
product.

Ton

All uses of term  "ton"  imply  short  ton  equal  to  2,000
pounds.
                          105

-------
                                    TABLE  XIV-J.

                                   METRIC TABLE

                                 CONVERSION TABLE
MULTIPLY (ENGLISH UNITS)

    ENGLISH UNIT      ABBREVIATION
acre                    ac
acre - feet             ac ft
British Thermal
  Unit                  BTU
British Thermal
  Unit/pound            BTU/lb
cubic feet/minute       cfm
cubic feet/second       cfs
cubic feet              cu ft
cubic feet              cu ft
cubic inches            cu in
degree Fahrenheit       °F
feet                    ft
gallon                  gal
gallon/minute           gpm
horsepower              hp
inches                  in
inches of mercury       in Kg
pounds                  Ib
million gallons/day     mgd
mile                    mi
pound/square
  inch (gauge)          psig
square feet             sq ft
square inches           sq in
ton (short)             ton
yard                    yd
* Actual conversion, not a multiplier
     by                TO OBTAIN  (METRIC UNITS)

CONVERSION   ABBREVIATION   METRIC UNIT
                            hectares
                            cubic meters

                            kilogram -  calories

                            kilogram calories/kilogram
                            cubic meters/minute
                            cubic meters/minute
                            cubic meters
                            liters
                            cubic centimeters
                            degree Centigrade
                            meters
                            liters
                            liters/second
                            killowatts
                            centimeters
                            atmospheres
                            kilograms
                            cubic meters/day
                            kilometer

                            atmospheres (absolute)
                            square meters
                            square centimeters
                            metric ton  (1000 kilograms)
                            meter
0.405
1233.5
0.252
0.555
0.028
1.7
0.028
28.32
16.39
0.555(°F-32)*
0.3048
3.785
0.0631
0.7457
2.54
0.03342
0.454
3,785
1.609
(0.06805 psig +1)*
0.0929
6.452
0.907
0.9144
ha
cu m
kg cal
kg cal/kg
cu m/min
cu m/min
cu m
1
cu cm
°C
m
1
I/sec
kw
cm
atm
kg
cu m/day
km
atm
sq m
sq cm
kkg
m
                                         106
                                                         A U.S. GOVERNMENT PRINTING OFFICE: 1976- 210-810/151

-------

-------
U.S. ENVIRONMENTAL PROTECTION AGENCY
WASHINGTON, D.C. 20460

    WH  552
           POSTAGE AND FEES PAID
ENVIRONMENTAL PROTECTION AGENCY
                        EPA-335

-------