TD433
.512
United States
Environmental Protection
Agency
Office of Water
Program Operations (WH-595)
Washington DC 20460
              October 1979
                              FRD-9
              Determining
              Wastewater Treatment
              Costs
              for Your Community
                           430979507
          U.S. Environmental Protect Agency
          Region V, Library
          23d Soutfc Dearborn Street
          Cfrfcggo. Illinois  60604

   SORg^Y
                          %
   M.F.X,MiHI* HKMTII WIT

-------
Copies of this Publication, FRD-9, Determining
Wastewater Treatment Costs for Your Community
are available from the address below.  When
ordering, please include the title and FRD
number.
    General Services Administration (8FSS)
    Centralized Mailing Lists Services
    Building Ul, Denver Federal Center
    Denver, Colorado  80225

-------
                         Determining Wastewater
                         Treatment Costs for
                         Your Community
This publication was prepared for the U.S.
Environmental Protection Agency by Sage Murphy
and Associates, Inc., Denver, Colorado under the
direction of:

    James A. Chamblee, Chief
    Priorities & Needs Assessment Branch (WH-595)
    Office of Water Program Operations
    U.S. Environmental Protection Agency
    Washington, D.C.  20460
    (202) 426-4443

-------
                Table of Contents

                                       Page No.

Why Treat Wastewater                      2
How Wastes are Collected                  3
Costs for Wastewater Collection           4
Enlargements and Upgrades of Existing
  Wastewater Treatment Plants             7
Costs for Wastewater Treatment            7
New Plant Construction Costs              9
Operation, Maintenance, and Routine
  Replacement Costs                      12
Component Parts of Annual Operating
  and Maintenance Costs                  14
Annual Treatment Plant Operating
  Expenses                               16
                        11

-------
INTRODUCTION

    Public  Law 95-217,  The Clean  Water  Act of
1977,  has  mandated the  nation's waters  must be
protected  from pollution and  existing pollution
levels must  be reduced.  One  of the  provisions
of the Act is  to  assist municipalities and other
public dischargers  of  waste  with  the financial
burden   of   necessary   construction   of   the
pollution  control  facilities.    In most  cases,
the   Federal  government   will  contribute   75
percent  of  the  construction  costs  while  the
local share will be 25 percent.

    In addition,  EPA encourages  small treatment
systems and  innovative  and  alternative treatment
systems;  because they often are  less costly than
traditional  treatment methods,  resulting in cost
savings   to   both    the  community   and   EPA.
Innovative and alternative  treatment systems can
receive up to 85 percent Federal funding.

    In order  to  choose  the most viable approach
for  wastewater treatment,  it  is important  that
communities  have  a  general  idea of the potential
costs  as  they begin  the planning  process.   The
U.S.  Environmental  Protection  Agency  (EPA)  is
providing  this brochure to assist  you  and  your
community  in determining the  approximate cost of
building  and  operating a  municipal  wastewater
collection  and treatment  system.   The  brochure
has  been  developed for  facilities   serving less
than 50,000 people.

    We   have   developed   the   cost   to   your
community, which  is "average"  for the population
served.   The  data  from which   these  estimates
were  derived  are  from national  averages.  Costs
in  your  locality will  probably  vary  from these
averages  due  to  regional  economic differences,

-------
climate,  terrain,  and  other  factors.   Before
outlining  this  general  cost  information,  it is
necessary  to present  background  information on
wastewater collection  and  treatment, as  well as
some of the  assumptions used  to  arrive at these
national averages.
WHY TREAT WASTEWATER

    Water   has   long  been   used   to  transport
unwanted   materials   away   from   our   homes,
businesses,  and  industries.    About 26  billion
gallons of  wastewater are generated  in the U.S.
daily.   The  wastewater  is  composed  of  organic
compounds  from  plants,  animals, and  humans; and
inorganic  compounds  from household  activities,
industrial  proceses,  and  commercial   practices.
These   wastes   take  the   form   of  particles
suspended   in   the   water,   commonly   called
Suspended   Solids   (SS)   or   wastes   that  are
dissolved  in the  water.   Suspended  solids can
harbor  harmful  microorganisms  (typhus,  polio,
etc.) and toxic chemicals.

    Organic  matter  in wastewater  serves  as food
for  bacteria  and  other   small  organisms.   The
amount  of  oxygen  needed  by  the   organisms   to
oxidize  the  organics for food  and   energy   is
called  Biochemical  Oxygen Demand  (BOD).   BOD  is
an  important  measurement, as  aquatic  life   is
dependent  upon  the  amount  of  oxygen  in the
water.   A  depletion  of  available  oxygen can
decrease  the  desirable   aquatic  populations   in
our waterways, causing fish kills for example.

    Inorganic  materials  present   problems   also.
Phosphorus  and  nitrogen  act  as   nutrients for
algae   and  other   growths   which   can  deplete
streams of  oxygen,  can cause  odor  problems, and

-------
are generally  unsightly.   High levels of certain
chemicals  such as  mercury,  lead,   cadmium,  and
zinc are  suspected  of causing certain sicknesses
in humans.

    Untreated  wastewater  can,  therefore, deplete
our  streams   of   fish   and  wildlife,  transmit
diseases,  reduce  property  values,  and generally
prove a public nuisance and health hazard.

HOW WASTES ARE COLLECTED

    Our  sewer  systems  are  composed  of piping,
pump  stations, manholes,  and associated  items.
The   sewer   pipes   are   separated   into   four
categories:    house   connections,   collectors,
interceptors,  and  force mains.   These different
types  of  sewers  may  be  compared  to  our  city
street system:  house  connections are similar to
driveways,  collectors  are  similar   to  suburban
streets,    interceptors   are   similar   to   major
highways.

    House  connections  carry wastewater  from the
house  into the collection  system.   The  cost  of
house  connections  must  be  borne  completely  by
the homeowner.  The wastewater  flows  from house
connections  into  collector   sewers.   Collector
sewers  are  eligible   for  Federal  funding  in
communities  existing  before October  1972,  where
there  are no  sewers  now.   New  communities,  or
newly  developed  areas   of existing  communities
must bear  the  entire  cost  of  the collectors.  In
many  States,  however,  collector  sewers  do  not
receive a  sufficiently  high priority  to receive
any  funds.    The   main  conveyance  pipe  which
gathers flows  from  the  collectors and transports
the wastewater to  the treatment  plant is called
an  interceptor.   Depending  on   the   terrain,  a
force  main  may  be  necessary  to  carry  water,

-------
under  pressure,  from  a  pump  station  to  the
treatment plant.   Interceptors,  force mains, and
pump  stations  are  all  fundable by  the Federal
government.  The  Federal government  will  pay 75
percent  of  the  cost on  all  eligible items.  The
community  is responsible  for  finding  funds  to
cover the remaining costs.

COSTS FOR WASTEWATER COLLECTION

    The  costs  of  a  sewer   system  vary  widely
among different localities.   These variances are
influenced   by   climate,    terrain,   population
density,  soil  condition, and  cost of  living to
name  but a few.   Reasonable costs  for the grant
eligible  portion  of  a  sewer  system  range  from
$500  to  $1,500  per  person  served,  the average
being  approximately  $1,000  per  person.   This
average  is  for those communities  with eligible
collector   and  interceptor   sewers.    Of  these
totals,  the  Federal  government  pays  $750  per
person  and  the community  pays  $250  per person,
on  the  average.    The  homeowner  must pay  any
additional  costs   for  the house  connection  and
any hookup  charges.

    If   your  community  is  not  eligible  for
Federal  grants  for  the  collector  systems,  and
none  are  presently  existent,  the  total  costs
will  remain  approximately  the same,  but  the
community   will  be  responsible for  a  greater
share.   The cost  of  the collection  system must
be  added to the  treatment costs mentioned later
in  the  brochure  to  give  an  estimate  of  total
costs.

HOW WASTES  ARE TREATED

    Wastewater    treatment    is    designed   to

-------
accomplish   in   a    controlled    and   managed
environment what  occurs in  nature  under  a  much
slower  process.   The   contaminants  are  removed
from   the  wastewater  by   various   physical,
chemical, and biological processes.

    There  are  three basic  levels  of  wastewater
treatment:   primary,   secondary,   and  advanced
treatment.  The  objective  of primary treatment
is  to  remove  readily  settleable  and  flotable
material,  thus reducing the amount  of suspended
solids  (SS).  Secondary treatment  is designed to
remove  dissolved  pollutants and  provide  greater
efficiencies   in   suspended   solids   removal.
Advanced  treatment  is  used  for  phosphorous  and
nitrogen  removal or  for greater  reduction of BOD
and SS.

    The   effluent   (treated  wastewater)   of  a
sewage  treatment plant  must  meet  certain Federal
or  State   water  quality   criteria.   Secondary
treatment   is   now   the  minimum   requirement.
Advanced   treatment   may  be  required   if  the
receiving   body   of   water   is   particularly
sensitive  to  certain  pollutants,  or  to  protect
the health and welfare of people and wildlife.

    Since  secondary  treatment  is  the  minimum
level   of   treatment   required  by   law  and  is
usually   used    in   conjunction   with   primary
treatment, emphasis  will be placed  on it.  Most
new  treatment  plants   in  this  country will  be
some  form  of  secondary.    Secondary  treatment
utilizes  the  natural  process of  microorganisms
feeding  on organics in  the water  which  reduces
the BOD.   The  process  creates an  ideal, confined
habitat,  providing  proper  light,  temperature,
oxygen,  and  food  for  the  microorganisms.   A
secondary  treatment  plant  generally  consists of
screening  devices,  a  settling   tank  (primary

-------
treatment,  SS  removal),  a  biological  treatment
unit   (secondary   process,   BOD   removal),   a
secondary   settling   tank,   and   chlorination
(disinfection).    The  material  settled  out  in
sedimentation tanks,  called  sludge,  is  further
reduced  or  densified  by  digestion,  thickening,
drying,  or  incineration  processes  for  safe and
easy final disposal.

    A  variety  of  biological  processes  can  be
used for  secondary  treatment.  Some of  the most
common   are  lagoons,   activated  sludge,   and
trickling  filters.    Lagoons are  large  shallow
ponds  where wastewater  is  held for a  period of
time while  a biological  community  feeds  on the
organics  in the  wastewater.   Some lagoon designs
provide  for addition  of  oxygen to the  ponds by
using  aerators,  thus  increasing the  biological
activity  and  treatment  efficiency.    Activated
sludge  processes  consist  of  a tank  in  which
sufficient   air   is   supplied   to   support   a
biological  community.   With trickling  filters,
the biological communities are grown on  a  fixed
media  rather  than  in  the  water.    Trickling
filter plants spray the  wastewater  onto rocks or
plastic  media  to  which  microorganisms  attach
themselves  and   use  the  wastewater  as  a  food
source.

    Plant   size,   strength  of  incoming  wastes,
effluent     requirements,    climate,     energy
requirements,     and     operating     manpower
requirements are  some of  the  factors  which bear
upon   the  selection   of   secondary   treatment
processes.

    Advanced  treatment  can  usually  be achieved
by  adding processes to  a  secondary  plant.  Some
advanced  treatment  processes add chemicals  which
enhance  the settling  properties of the suspended

-------
materials.  Some  are  processes which  use  a form
of  filtration  to  refine the  secondary effluent.
Land   treatment   of    wastewater   may   achieve
advanced   treatment    standards    by   applying
partially treated wastewater to land.

ENLARGEMENTS AND  UPGRADES  OF  EXISTING WASTEWATER
TREATMENT PLANTS

    Existing  treatment plants  that  cannot meet
present  effluent  requirements must  be upgraded.
This   includes   all   primary   plants,   since
secondary treatment in now the  required minimum
level  of treatment,  and  plants  in  areas where
discharges are  restricted  and advanced treatment
is  required.    An  upgrade  can  range from  the
modification   of   present   processes  to  the
addition  of  totally new processes.   A treatment
plant  may also  need  to be enlarged  to  relieve
overloaded conditions.   The  type  and  extent  of
the needed  additional  construction  is dependent
upon  the individual  community and  the  existing
plant  (present   capabilities,   adaptability  to
modification,     etc.).     In   enlarging    and
upgrading, a complete  evaluation of the existing
system is essential along  with  a  detailed study
of    alternatives.     Costs   associated    with
enlarging  and  upgrading   plants  are  so  plant
specific  that  reasonable  cost  estimates   cannot
be presented within the scope of this brochure.

COSTS FOR WASTEWATER TREATMENT

    The   choice   of  treatment  alternatives  is
dependent upon  variables  such as  climate, land
availability,    waste    constituents,   effluent
restrictions,   general  community  goals,  process
reliability,  and  costs.  There is  no single best

-------
                        8

method  of treatment.   The  deciding  factor when
considering alternatives  often  is  system  costs,
not  only the  initial  capital   outlay,  but also
the yearly charges that the community must meet.

    The  Federal  government will  fund 75 percent
(85  percent  in  some  cases)   of  the  costs  for
treatment plant  construction.   This includes new
construction,   enlarging  or  upgrading   a   plant.
The  only nonfundable portion is the  cost of the
land  on  which  the   plant  is   built.   Land   is
fundable  only  if it  is  used for land application
of   wastewater.     The    annual    operation  and
maintenance costs  of the  treatment facility are
completely the responsibility of  the  community.
These costs are  shared  by the homeowners through
hookup   and   user   charges.    Industries  which
discharge  into   the   treatment  system  pay   a
portion   of   yearly   operating   expenses    in
proportion to  their  use.

    Costs  are  presented  for   lagoons,  other
secondary   plants,   and   advanced    treatment
plants.   Costs presented include  total cost for
new   construction,   yearly     treatment   plant
operation, maintenance, and  routine  replacement
cost,  and the annual  operating expenses  of the
plant.   These  costs may  vary  due  to  regional
labor  rates,  chemical  costs, utility costs,  and
construction  material  costs.   All costs  are  in
January,  1979  dollars.    Estimates for  inflation
between  that  time  and  now  should  be  used  to
determine the  present cost.

-------
NEW PLANT CONSTRUCTION COSTS

    Figure  1  provides  average costs (in millions
of  dollars)  derived  from  historical  data  for
construction   of    new    plants.     A   general
assumption  made  when  determining  plant  size is
that  100 gallons  of  wastewater  per  person  per
day is generated.  The graph  covers a population
of  zero  to  50,000.   The  actual  flow  for  a
community can vary widely  depending upon locale,
climate,  size of  community,   and  the  degree of
industrialization.
EXAMPLE

    The  example  presented  below  provides  new
plant   construction   costs;   annual   operation,
maintenance,  and  routine replacement  costs;  and
annual  treatment  plant  operating  expenses  for
constructing   and   operating  a   new  secondary
treatment plant for a community of 25,000 people.

POPULATION:

NEW PLANT  CONSTRUCTION  COSTS:   From the graph in
Figure  1,  follow the  line up from the population
(25,000)  until  it  cuts  across  the  secondary
treatment  curve.    Follow  the line  across  the
vertical  cost  scale.   Read  the  cost   from  the
scale  in  millions  of   dollars  =  4.8  million
dollars.

    CAPITAL OUTLAY = 4.8 x 1,000,000 = $4,800,000

-------
                        10

SAMPLE FORM (For your community)

POPULATION SERVED:
TREATMENT
LEVEL:
CAPITAL  OUTLAY:    From  the  graph  in Figure   1,
trace      a      line      up      from      the
population 	 to  the  treatment level
curve, across  the  cost  scale.  Enter the cost  in
the     blank    and     multiply     by     1,000
dollars.	 x       1,000      dollars
= 	.   Enter  this  figure  in the  blank
below for new plant construction costs.

    CAPITAL OUTLAY = $	

-------
      FIG. 1
      NEW  PLANT CONSTRUCTION  COST
   9-
   8-
   7-
  '-
S  5-

_i


I
v_  4-

t-


o

U  3-






   2-







   1-
                                            ^




                                          AWT
                                    .^*
                                      SECONDARY
                       
                           +             .
                                     0^l LAGOONS



                           ,-"""
         5   1O    15  2O   25   3O   35   4O




         POPULATION (THOUSANDS OF PEOPLE )
                                              0
           ASSUMING 1OO GAL. PER CAPITA PER DAY

-------
                        12

OPERATION,  MAINTENANCE,  AND  ROUTINE REPLACEMENT
COSTS

    Figure  2  presents annual  costs  (in thousand
dollars   per   year)   to  operate   and  maintain
treatment plants.  Costs  for lagoons, secondary,
and advanced treatment plants are given.

EXAMPLE

ANNUAL   OPERATION,   MAINTENANCE,    AND   ROUTINE
REPLACEMENT COSTS:   From  the graph  in  Figure 2,
follow  the  line up  from  the population (25,000)
until  it  cuts  across  the  secondary  treatment
curve.   Follow the  line  across to  the vertical
cost  scale.   Read  the cost from  the scale in
thousands  of  dollars per  year  =   200  thousand
dollars

    O&M  COSTS:   200  x  1,000  =   $200,000  per
    year

SAMPLE FORM (For your community)

ANNUAL   OPERATION,   MAINTENANCE,    AND   ROUTINE
REPLACEMENT COSTS:   From  the graph  in Figure 2,
trace  a  line  up from  the  population 	 to
the  treatment   level  curve,   across  to  the  cost
scale.  Enter  the  cost  in  the blank and multiply
by   1,000   dollars.   	 x  1,000  dollars
= 	 .   Enter this  figure   in  the blank
below  for  total  annual  operation,  maintenance,
and  routine  replacement   cost,  in  dollars  per
year.

    O&M COST =  $             PER YEAR

-------
       FIG. 2
                ANNUAL O &  M COSTS
  6OO-1
   soo-
tt
<
_i

O
o

O
z
<
/)

O
I/)
O
   400-
   300-
   2OO
   100-
                                       X

                                                      AWT
                                                   SECONDARY
                                                LAGOONS
      O     5    1O    15    2'O    25    3O    3'5    4'O   45    5O



             POPULATION (THOUSANDS OF PEOPLE)
               ASSUMING 1OO GAL.PER CAPITA PER DAY

-------
                        14

COMPONENT   PARTS   OF   ANNUAL   OPERATING   AND
MAINTENANCE COSTS

    The    pie   diagram    (Figure    3)    below
demonstrates   the    relative    proportions   of
components  which  make  up  the  annual  cost  of
operating and maintaining  a  plant.   This  can aid
a  community in  determining  what  impacts  future
increases   in  utility   rates,   chemical  costs,
labor  rates,  or routine  replacement  costs  will
have on operating costs.

-------
:IG.3
           PROPORTIONATE  O & M COSTS
 .AGOONS
SECONDARY
AWT
                                          UTILITIES
MATERIALS




CHEMICALS




OTHERS (4%)*











UTILITIES










MATERIALS







CHEMICALS





OTHERS
                                         UTILITIES
                                         MATERIALS
                                         CHEMICALS
                                         OTHERS

-------
                        16

ANNUAL TREATMENT PLANT OPERATING EXPENSES

    Annual  operating expenses  are  those  costs,
calculated  on  a  yearly basis,  required  to  own
and operate  a facility.   They  include principal
and interest payments for  retirement of any debt
acquired  for the  construction,  yearly salaries
for  manpower   (including   overhead  and  fringe
benefits),   chemical   and   power   costs   for
operation, and all  costs  associated with routine
replacement and maintenance of  the facilities.

    Annual operating expenses  for municipalities
were   developed   assuming  75   percent  Federal
funding  and  25  percent  municipal  funding  of
construction  costs,  general  obligation  bonding
at  six percent  compounded semiannually for  20
years,  and  100  percent   municipal   funding  for
annual  operation  and  maintenance  costs.   The
municipality's   share   in   terms   of   annual
operating  expenses  (in  thousands  of dollars  per
year)   is  presented  in  Figure 4 for a population
range of zero to 50,000.

-------
                        17

EXAMPLE

ANNUAL TREATMENT  PLANT  OPERATING EXPENSES:  From
the graph  in Figure 4,  follow the  line  up from
the population  (25,000)  until it outs across the
secondary   treatment   curve.    Follow  the  line
across  from  the  intersection  to   the  vertical
cost  scale.  Read  the  cost  from  the  scale   in
thousands  of  dollars  per  year  =   325  thousand
dollars.

    ANNUAL  TREATMENT  PLANT OPERATING EXPENSES  =
    325 x  1,000 = $325,000 per year


SAMPLE FORM  (For your community)

ANNUAL TREATMENT  PLANT  OPERATING EXPENSES:  From
the graph  in Figure 4,  trace a  line up from the
population 	 to  the   treatment  level
curve, across  to  the  cost scale.  Enter the cost
in    the    blank    and    multiply    by   1,000
dollars.   	 x         1,000          dollars
= 	.   Enter  this   figure  in  the
blank  below   for   the   annual  treatment  plant
operating   cost  in   dollars  per   year  which
includes  the  municipality's  25  percent  share  of
the capital  outlay  and the bond debt retirement
plus  the   annual   operation,  maintenance,  and
routine replacement costs.

    ANNUAL  TREATMENT  PLANT OPERATING EXPENSES  =
    $	 per year.

    The    annual    treatment    plant   operating
expenses are  a  rough planning  level estimate  of
what  the  new  treatment  plant  will  cost  the
community.

    Remember  that   the   actual  costs  in  your
community may be very different;  because we have
used   national   average   costs  for  treatment
plants, and  we  have not  included any  costs  for
the sewage collection system.

-------
     FIG. 4
   8OO-
<  7OO-
BL  600-
(A
Of
j  5OO-
O
O
O  4OO-
z
O 300
O
u
  200-
   100-
           ANNUAL TREATMENT  PLANT
               OPERATING EXPENSES
                                               AWT
                                   *
                                       %
                                             SECONDARY
                              ....... ,
                                     "
                                      ................
                                              LAGOONS
               1O    15   2O   25    3O   35   4O   45   SO
            POPULATION (THOUSANDS OF PEOPLE)
             ASSUMING 1OO GAL. PER CAPITA PER DAY

-------
                               19

       REFERENCES  AND  ADDITIONAL SOURCES OF INFORMATION

       1.   Environmental  Pollution Control
           Alternatives:   Municipal  Wastewater
           (EPA-625/5-76-012).

       2.   A  Primer  on Wastewater Treatment (Office of
           Public  Affairs,  A-107, July  1976).

       3.   Construction Costs  for Municipal Wastewater
           Treatment Plants:  1973-1977
           (EPA-430/9-77-013,  MCD-37).

       M.   Analysis  of Operation and Maintenance Costs
           for Municipal  Wastewater  Treatment  Systems
           (EPA-430/9-77-015,  MCD-39).

       5.   Construction Costs  for Municipal Wastewater
           Conveyance  Systems:  1973-1977
           (EPA-430/9-77-014,  MCD-38).

       6.   Cost Effective Comparison of Land
           Application and  Advanced  Waste Treatment
           (EPA-430/9-75-015,  MCD-17).

       7.   All You Need to  Know About Sewage Treatment
           Construction Grants (Office  of Public
           Affairs,  A-107,  August 1976).
V U S GOVERNMENT PRINTING OFFICE 1979  681-529

-------

-------