\lt
                     United States
                     Environmental Protection
                     Agency
Robert S. Kerr Environmental
Research Laboratory
Ada OK 74820
                     Research and Development
EPA-600/S2-83-026 May 1983
&EPA          Project  Summary
                     Design  Principles  for  Wetland
                    Treatment Systems
                     David E. Hammer and Robert H. Kadlec
                      Published data pertaining to the
                    treatment of wastewater by wetland
                    irrigation have been  assembled and
                    analyzed to begin identifying general
                    principles for the successful design of
                    wetland facilities. Sources of operating
                    data have been tabulated. Performance
                    is roughly correlated with overall sys-
                    tem features, but cannot be predicted
                    on  the current basis.  Existing com-
                    partmental  models require more de-
                    tailed information than does or will
                    exist; thus a simplified compartment
                    model is presented.
                      Water quality is controlled by rapid
                    processes related to water movement,
                    mass transport to other compartments,
                    and consumption kinetics. Thus, wet-
                    land hydrology is fundamental to the
                    analysis of water quality improvement.
                    The ultimate fate of nutrients and con-
                    taminants is determined by sedimen-
                    tation, biomass production  and har-
                    vest, soil and microbial  processes.
                    Required wetland area depends on
                    effluent quality, ecosystem type and
                    age, and hydraulic regime. These ques-
                    tions can be addressed in terms of a
                    mass transport model for the zone of
                    rapid removal, and a "saturation" model
                    for the expansion of a zone of stabilized
                    activity about the discharge  point.
                    Material balances, considering only
                    long-term consumption mechanisms
                    for  nutrients and other pollutants, de-
                    termine the useful life and  ultimate
                    performance of a wetland system.
                      Operational techniques and the use
                    of constructed wetlands are also con-
                    sidered.  The economics of wetland
                    treatment are discussed.
                      This Project Summary was developed
                    by EPA's Robert S. Kerr Environmental
                    Research Laboratory, Ada. OK, to an-
nounce key findings of the research
project that is fully documented in a
separate report of the same title (see
Project Report ordering information at
back).

Introduction
  The treatment of wastewater by over-
land  flow through a wetland is  a new
concept  Only in the last decade has the
performance of such  systems become a
topic of scientific study. Wastewater dis-
charges to wetland areas are not a new
practice, for a number of sites have been
identified where discharge has been on-
going for more than half a century. New
treatment systems are being established
at natural wetlands and at wetlands specif-
ically constructed for this purpose.  Signif-
icant improvements in wastewater quality
are generally observed, at a cost which is
low when compared to other alternatives.
  The purpose of this study is to identify
data sources and to present certain design
concepts and their application to wetland
treatment
  The reliable design of a wetland treat-
ment facility requires the development of
performance equations which  describe
both  the response of the ecosystem to
wastewater additions and the alteration of
water quality.  These equations must be
developed from the  operating data of
existing systems and from insight obtained
from  research studies conducted in the
laboratory and at field sites. Since experi-
ence  is somewhat limited, only the basic
features of the wetland treatment process
are susceptible to meaningful  analysis.
These include wetland hydrology and
overland flow, removal  rates for waste-
water components,  and the effects of
nutrient additions on the continued ability
of a wetland to treat wastewater.

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  When wastewater is discharged to the
surface of a wetland it flows away, spread-
ing into a dynamic mound about the dis-
charge.  The depth which will result de-
pends upon the hydrological characteristics
of the wetland and impounding structures,
if any. Each wetland system has a hydraulic
capacity,  which  may change rapidly in
response to  ram or other hydrological
factors. Depth limits will be determined by
the tolerance of wetland vegetation and by
consideration of operating factors such as
residence time.  Depth and velocity will
also affect the ability of  the wetland to
remove pollutants from the surface waters.
Hydrology of the wetland site is therefore
crucial to the understanding of the treat-
ment processes which occur.
  The  rate at which  pollutant  removal
occurs will determine the  relationship be-
tween  the  wastewater  inputs  and the
quality of the wetland effluent These and
other parameters, such as removal effi-
ciency, are interrelated through a material
balance about the surface waters. There-
fore, the removal rate for each component
must be determined. These rates can vary
with factors such as water flow rate, depth,
season, species  composition  within the
wetland, type of soil substrate, and the age
of the treatment facility.
  Prediction of removal rates, overtime, is
a primary task in  the analysis of a wetland
treatment system design. Two approaches
to this problem are possible: the correla-
tion of operating data from existing sys-
tems; and the development of a concep-
tual model  for  the wetland treatment
system.
  We have therefore reviewed data from
26 sites, as listed in Table 1.  Based on
these,  a model for the wetland treatment
system is proposed and analyzed in terms
of contributing processes.
   Evaluation of a proposed system design
must ultimately  turn to economics.  The
available data on capital requirements and
operating expenses were therefore col-
lected  and presented.

Wetland Hydrology
  The  design or evaluation of wetland
wastewater treatment systems requires a
sound understanding of the marsh  hy-
drology.   Surface water  flow rates, soil
infiltration, and depth are of primary con-
cern.  Water depths and flow  rates  are
usually  determined  by  natural stream
flows,  overland  flow, precipitation, and
evapotranspiration. Introduction of waste-
water  irrigation  may  result  in  localized
increases in water depths which in turn,
combined with increased nutrients, may
cause changes in the species composition
Table 1.    Site Summary List.
Site
Bellaire, Ml
Bradford, ONT
Bri/lion, Wf
Brookhaven, NY
Clermont, FL
Cootes Paradise, ONT
Drummond, Wl
Dulac, LA
Gainesville, FL
Great Meadows, MA
Hamilton, NJ
Hay River, NWT
Houghton Lake, Ml
Humboldt, SASK
Jasper, FL
Kesalahti, Finland
Kincheloe, Ml
Lake Balaton, Hungary
Las Vegas, NV
Listowell, ONT
Mountain View Sanitary
District CA
Seymour, Wl
Suisun City, CA
Vermontville, Ml
Waldo, FL
Wildwood, FL
Approximate
Age, yr.
12
1
56
6
4
62
3
2
7
68
2
16
4
2
60
-
25
-
60
2

7
2
5
2
46
20
Annual
Discharge
106 gal.
30
0.5
98
3
4
-
15
0.03
6
1600
1.7
11
100
10
-
-
150
-
30,000
15

255
0.1
20
25
30
55
Data Base
Size
Small
Small
Medium
Small
Medium
Small
Small
Small
Large
Medium
Small
Small
Large
Small
-
-
Small
Small
Medium
Medium

Small
Small
Medium
Small
Small
Small
Identifying
Number
In Figure 1
2
-
4
-
-
10
-
-
-
6
-
1
3
-
-
-
-
•
•
-
9
-
-
•
8
7

 of the  plant and animal communities.
 Removal  of  nitrogen,  phosphorus, and
 other pollutants is best accomplished  by
 slow overland flow of surface waters in a
 thin sheet or by infiltration.  Channelized
 flow, characterized by greater water depths
 and shorter residence times,tends to  re-
 duce the system's effectiveness for pollu-
 tant removal.
   In order to  properly assess the per-
 formance of a wetland, a complete water
 budget must be prepared.  All points of
 influx and efflux must be identified and the
 flows estimated throughout the year. Sim-
 ilarly, precipitation and evapotranspiration
 must be  quantified.  This water budget
 combined with  measurements of nutrient
 concentrations   can  provide a  complete
 picture of the wetland  treatment system
 performance.

 Correlation  of Operating Data
   Data from several wetland AWT sys-
 tems allow calculation  of the gross aver-
 age removal rates of phosphorus and
 nitrogen.  While precise relations cannot
 be established  using these data from  di-
 verse systems, a trend of increasing  re-
 moval rate with increasing nutrient con-
 centration is suggested. Plots of nutrient
 removal rate versus nutrient loading rates,
 as  shown in Figure 1  for  phosphorus,
 define the operating limits which are ob-
served on existing systems, regardless of
hydrology,  cover type, or climatic con-
siderations.

A Simplified Compartmental
Model
  Improved design techniques  require
consideration  of individual phenomena
and  processes within  the  wetland.   A
larger body of  reliable data is available on
the function of wetland subsystems than
on the performance of the wetland as a
whole. Relatively simple models of signifi-
cant ongoing processes make it possible
to obtain further insight into  the overall
interactions between the wetland and ap-
plied wastewater.  This procedure allows
the  synthesis  of a conceptual  model,
which when represented in mathematical
terms, can be used to evaluate a new
design.
  To facilitate the use of a model over long
periods of time (e.g., 20 to 50 years) a
simple, specialized structure is desirable,
as described in Figure 2.  All transfers
between  the surface waters and  the sta-
tionary ecosystem are taken as the annual
net accumulation in each compartment.  In
this way, cycling of nutrients and  other
materials on seasonal, or  even  shorter
term, basis  need not complicate the model.
   Removal  of  dissolved  nutrients
surface waters is controlled by

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                                                                 Q10, Shallow (55)
  • Total Dissolved Phosphorus
  O Rate Based on Growing Season,
r * Thus is Likely High Relative
    to Annual Average
              O Total Phosphorus
              I j Denotes Approx.
               Age of Site
                                               O 6, Shallow (69)
                                 1(15)
                                    3(1)
                                     ', Deep (55)
                              3d)        04(55)
                                 7       V
                                        '/
                                   100     200         500
                              Phosphorus Loading (kg/ha/yr)
                                                    WOO
                                                             2000
 Figure 1.
 Effect of phosphorus loading upon removal rate. (See Table 1 for site identification
 numbers.)
 Wastewater
 Additions

 Natural
 Water
 Inputs
 Water
 Outputs'
 Figure 2.
                                          Wetland
                                          Consumption
                                         \ Processes
                                                Biomass—Long- Term
                                                Retention of
                                                Nutrients and Other
                                                Substances in the
                                                Dynamic Biomass Pool
                                           Soil & Sediments-
                                           Solids Incorporated
                                           into the Soil Column
                            Stationary Wetland Ecosystem

 Simplified compartmental model for use in wetland treatment system design.
 process. The process consists of delivery
 and consumption.  Consumption occurs
 principally at the surfaces of the soil, litter,
 plant  stems and algal  mat  Delivery is
 accomplished by convective mass transfer
^within surface waters, overland flow, or by
 Hownward flow due to water infiltration.
"Consumption consists collectively of a
                              number of processes which  initially are
                              relatively fast, but of which  some slow
                              considerably as  wastewater  treatment
                              continues.  Sorption will reach an equilib-
                              rium in the upper soil horizons reducing
                              the average areal uptake rate. Similarly,
                              biomass expansion, which offers a sink for
                              nutrients, will also reach a saturation con-
dition, where the release of nutrients due
to litter decay offset any  uptake  in new
growth.  Woody biomass production  al-
lows longer  immobilization of nutrients
and  constitutes a  relatively permanent
removal mechanism. Soil production also
represents a  long-term  removal process
but is quite slow. While data are extremely
sparse, the same basic behavior  can  be
anticipated for heavy metals as well  as
nutrients.
  Two treatment regimes  will exist in an
older wetland system as shown in Figure
3.  In the vicinity of the wastewater dis-
charge a "saturated"  region will exist
Here component removal rates will  be
quite slow, comprised of the uptake rates
due to (1) sorption deep in the soil column,
(2) incorporation of material into new soil
and  woody plants,  and  (3)  microbial  re-
lease of gases to the atmosphere. Outside
this"saturated" region, surface water con-
centrations of  wastewater  components
will drop exponentially with distance.  In
this  latter zone of rapid  removal, it is the
transport of dissolved components through
the surface waters which limits the overall
rate. The amount of wetland area needed
for this zone of fast removal will be deter-
mined by mass transfer considerations
and  for  constant  operating conditions
(depth, velocity, etc.) will not change. The
zone in the "saturated" regime will con-
tinue removal at a rate which is slower but
insensitive to modest changes in water
flow or depth.  The expansion of this
saturated region continues until the total
affected  area is sufficient  to  allow  all
incoming wastewater components to  be
removed by water infiltration, incorpora-
tion  into new soil and woody biomass, or
release to the atmosphere.  If the  actual
wetland area is less than that required for
total retention of pollutants, breakthrough
will occur.  In this case,  only a portion of
the wastewater  components fed  to the
wetland will  be retained  and collection
efficiency will drop sharply.
  Harvesting plant biomass is a  direct
method of preventing saturation  of the
biomass  compartment.  Nitrogen,  phos-
phorus and other wastewater components
can be removed from the wetland system.
Higher removal rates can  be maintained
indefinitely with limited area,  using this
technique.
  To employ this conceptual model in the
evaluation of wetland system designs, it
must be cast in mathematical terms.


The Mass  Transfer Zone
  When wastewater is caused to flow over
the  surface of a wetland,  nutrients and

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   Zone of Rapid
   Removal
                      "Saturated Zone"
                                                           Wastewater Discharge
                                                           Point
   Unaffected Zone

Figure 3.    Schematic of the zone of affected soil and biomass.
other polluants are removed, primarily by
delivery to and consumption at solid sur-
faces.  At the wetland surfaces, sorption
and  microbial  processes may  occur,  as
well as plant uptake. Algal and duckweed
uptake  may occur  at the  upper water
surface.  These processes  require that
each  contaminant be transported to a
bounding channel surface.
  A typical relationship  to describe this
transport is:
           N = kA (Cw - Cs)
where:
  N  = contaminant transport rate, gm/day
  k = mass transfer coefficient, m/day
  A  = area of surface, m2
  Cw  =  contaminant concentration  in
       water,gm/m3
  Cs= contaminant concentration in water
       at channel surface, gm/m3.
    Such a rate expression  must  be
  coupled  with  mass balances  for the
  contaminant and for the surface water to
  predict the distance  or time  for the
  removal of a dissolved substance.
    The contaminant mass balance is,  for
  a linear-flow wetland
  v0shd-Cw=-k0(Cw-Cs)-
        dx
  where:
  Ce = the contaminant concentration in
       evapotranspired water, gm/m3
  Cp = the contaminant concentration in
       precipitation, gm/m3
  0  = flow porosity across the wetland
       surface
  0s = storage porosity
  h = depth, m
  t  = time, days
  x = distance, m
  v = actual velocity, m/d
  p = precipitation, m/d
  e = evapotranspiration, m/d
  i  = infiltration, m/d
At some upstream point, x = 0, the con-
centration will be known. Presumably this
is either the discharge point; or, if the area
around the discharge is saturated, it will be
the outer edge of the slow removal zone.
For example, the zone of  rapid removal
should begin near the discharge line for
denitrification (NOs' removal), since no
saturation can  occur.   For an  "older"
facility, this rapid uptake zone for phos-
phorus would begin at a distance where
saturation ends.
  This model may be easily solved  in a
variety of special cases.  It works well for
those sites where transect data are avail-
able with which to validate it  The mass
transfer parameter, k, and the depth-velocity
relation are site specific.

The  Loaded Zone
  The addition of nutrients to a natural or
newly constructed wetland will cause a
zone  of increased vegetative growth to
appear. This zone will expand with time
until either the permanent capacity of the
zone equals the loading rate or the loaded
zone reaches the boundaries of the wet-
land. The mathematical description of the
advance of such a loaded zone for each
substance of interest such as phosphorus,
consists of a mass balance on the zone and
the rates at which the substance is taken
up by  the stationary ecosystem.  These
uptake  rates fall in  three  general  cate-
gories.  The first of these is a permanent
binding of the substance in question, or a
gaseous loss to the atmosphere, such as
denitrification.  In these cases, a compo-
nent is permanently removed from surface
waters.  A second general  category con-
sists of an increase in the adsorbed quan-
tity of the substance, which  is the physical
or chemical binding  of the substance to
the soil substrate within the wetland. Such
processes are known to occur for phos-
phorus and ammonia, for example. The
third general category  of  nutrient con-
sumption is storage in an expanding bio-
mass compartment
  Other  uptake/release processes  also
occur in the wetland ecosystem at rapid
rates. An example of this is  the uptake of
phosphorus and nitrogen by algae. These
algae grow during the summer months,
die,  and contribute a certain amount  of
algal litter to  the sediment  layers within
the wetland.  These algal sediments de-
compose and re-release the nitrogen and
phosphorus that was incorporated in the
biomass. This process is fairly rapid in the
summer months, and if one considers only
year-to-year variations in area, this process
is too fast to be noticeable.  There is little
net effect of such rapid cycling.  A second
type of rapid cycling of nutrients is the
uptake  by vascular  plants. With their
senesence and  death,  the leaching  of
nitrogen, phosphorus and carbon from the
biomass directly back to the water column
occurs yearly. This cycle is also too fast to
be  considered  in  a  framework that  is
geared  to predicting the change of the
affected area  from year to year.  Thus, in
the  model development which  follows,
only those processes which persist for a
period  greater than one growing season
are considered  as long-term consumers
for nutrients.   Put in another way,  all
quantities are expressed as rates, but
these are averages over the period of one
year or longer.
  To make this model more tractable, it is
assumed that sufficient residence time is
provided so that all material can reach the
plant and soil community.  The zone of
mass transfer limitation of the  removal
rate is neglected. This idealization results
in a sharp line of demarcation between the|
loaded and unloaded zones. This is not"

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entirely accurate since according to the
principles of mass transfer a zone must be
present in which  nutrient  levels within
surface water are decreasing.
   In terms of the possible sinks, the mass
balance equation in words is:
   addition   rate  =  sorption   rate  +
      permanent removal rate
      + temporary binding rate
      + discharge rate.
A variety of ways of expressing  these
terms exists; one set of choices leads to
the following mass  balance for the ex-
panding loaded zone:

where:
QC, = kyCi ^+ (rsCs + rA + rwXw +rHXH) A



Q  = average annual wastewater addition
      rate, rnVyr [380,000]
Cj  = mass average concentration of con-
      taminant or nutrient in influent waste-
      water, gm/m3 [3.5]
A  = area, m2
tr = time, yr
k  = sorption equilibrium constant,
      (gm/m3)s/(gm/m3)i[2.7]
Ci  = average contaminant concentration
      in surface water, gm/m3 [1.8]
y  = average sorption depth, m [0.05]
rs  = excess average annual soil accretion
      rate, m/yr [0]
Cs = contaminant concentration in new
      soil, gm/m3
TA  = excess average annual rate of loss to
      atmosphere,  gm/m2/yr [2.1 ]
rw = excess average annual woody stem
      accumulation rate, gm/m2/yr [0]
Xw = fraction contaminant in woody stems
rn  = average annual harvest rate,
      gm/m2/yr [0]
XH = fraction  contaminant  in  harvested
      biomass
F  = average annual excess  litter fall,
      gm/m2/yr[1600]
a  = average annual specific litter decay
      rate, yf1 [0.15]
XL = fraction contaminant  in remaining
      litter. [0.2]
  The word  excess  used above means
above background.  System parameters
were estimated for operation of the Hough-
ton Lake treatment site. Utilizing the mass
balance equation, the predicted nitrogen
from  progression was calculated.   The
observed system behavior and the predic-
tion, based on the data given above, for the
nitrogen front movement are shown in
Figure 4. These data are from operational
specifications and prior field research.
  The expansion of the "saturated" zones
about the discharge point have been found
     200
 1
 •I
 Q.
 Q
  5
 I
     ;oo -
 Figure 4.    Movement of nitrogen (NHS-N) concentration fronts in surface waters, C= 1 mg/l.
            Houghton Lake treatment site.
to be much as predicted by the material
balance,  considering  only  the  principal
mechanisms. The aging of the Houghton
Lake site can so far be described by this
model.

Wetland System Design:
Synthesis
  The  design process consists of two
distinct phases,  synthesis and  analysis.
Synthesis is the development of a plan for
a wastewater treatment facility.  Analysis
is the  evaluation of that plan and con-
cludes by  acceptance of the proposed
design  or  rejection  and another try at
synthesis There are no explicit equations
for synthesis.   Design parameters  are
chosen based upon  past experience or
educated guesses.
  If a wetland treatment system is to be
built in a natural wetland,  the designer
may have little freedom in synthesis. This
phase may consist largely of site selection.
Since one of the principal costs in wetland
treatment is a wastewater delivery system
(piping, pumps, etc.), proximity of the site
is fundamental.  Technical questions are
not the only ones which the designer must
address.  Land ownership,  political con-
siderations, and public attitudes  must be
investigated.   In the case of a natural
wetland site, environmental impacts will
be of particular concern.  It is extremely
important to maintain open channels of
communication between the designers
and the community, regulatory agencies
and any other concerned parties.
  With a natural wetland, the only con-
struction needed is often a wastewater
delivery line. Since wetlands tend to be at
low elevations, delivery can sometimes be
accomplished without a transfer pump, by
gravity flow. Wastewater can be effective-
ly applied to the wetland by a number of
schemes.  If flows are small (less than
about 100,000 gallons per day) water can
be discharged from several  nozzles  or
even at a single point  Larger flows can
be better accommodated by a linear dis-
charge.  This can be conveniently obtained
by using gated irrigation pipe.  The choice
of material for distribution  lines is gen-
erally aluminum irrigation pipe or plastic
pipe.   At  northern sites,   provision  for
draining the lines in winter  should be
included to prevent damage  by ice.   In
some cases, these lines can be  run directly
on the surface of the wetland soi I • however,
provision should be made to prevent the
pipe from sinking into the peat under its
weight when filled.  The distribution piping
has been successfully supported by logs
or an elevated platform, which also serve
as a convenient walkway.
  Placement of pipe, platforms and other
material in the wetland can pose a prob-
lem.  In  northern climes, this is often best
accomplished when ice cover has formed.
Heavy equipment can be used with min-
imal  residual damage to the vegetation.
  The construction of artificial  marshes
for wastewater treatment  theoretically
provides a number of technical advan-
tages. Control can easily be  maintained
over water levels and flow rates. The soil
plants  and other component parts  in-
cluded in the system can be selected for
their ability to treat wastewater.  Treat-

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ment cells can be shaped like ditches or
large basins, which can be lined to assure a
bottom seal. The wetland can be built in a
configuration which permits easy harvest-
ing of biomass. Cells can be operated in
batch-mode, offering reliable control on
the quality of effluent.  The constructed
wetland can be located conveniently.
  The political advantages  may be even
greater than these technical advantages.
While objections are sometimes raised to
wetland treatment sites utilizing natural
marshes, the constructed  wetland  con-
cept circumvents much of the controversy.
In many aspects, the constructed wetland
is akin to a piece of processing equipment
at the municipal treatment plant
  Operation of a wetland treatment facility
generally involves establishment of a dis-
charge schedule and monitoring activities.
In certain cases, biomass harvesting may
also be considered. The discharge sched-
ule in northern climates is usually seasonal.
Wastewater is held in  ponds during the
winter and discharged only during  the
warm months,  when plants, algae, and
microorganisms are most active.

Economics
  The economics of wetland treatment are
attractive in those situations where a suit-
able  land parcel  exists adjacent to the
community.  This appears to  be  true
whether or not an existing wetland elimi-
nates some construction costs.
  The basis for an estimate must contain
the following key items:
    1. Total acreage to be obtained, for
      both irrigation and isolation.
    2. Flows,  both annual  average  and
      irrigation season actual.
    3. Distance to the  wetland from the
      treatment site.
    4. Length of distribution pipe required
      within the wetland.
    5. Pumping requirements, if any, ex-
      pressed  in terms of  static, friction
      and site discharge heads.
    6. Disinfection requirements.
    7. Harvesting requirements.
    8. Grading, ditching and diking  re-
      quirements.
    9. Plant community establishment
   10. Wetland discharge  collection sys-
      tem.
The first seven items are common to all
systems;  the  last three  pertain only to
constructed wetlands.
   This type of analysis shows the major
contributions to capital costs for an exist-
ing wetland to be pumps and piping, land
and land  access.and disinfection.   Site
alteration must be added for a constructed
wetland.  The major contributions to oper-
ating and maintenance expense are man-
power, pumping energy, and monitoring
costs.
  Capital costs, estimated and actual, are
shown in Figure 5.   The estimates are
those of Sutherland (1978).  The data are
lower than these estimates for four cases
and higher for two cases.
  Operation and  maintenance (0 & M)
costs are shown in Figure 6,  with Suther-
land's  (1978)  estimates as a referent.
Data are sparse, and difficult to determine
accurately,  but actual systems are cheap
to run by any standard. They require little
attention,  essentially  no chemicals, and
have simple equipment
  Capital recovery costs and  0 & M costs
combine to  yield a cost for advanced
secondary treatment for a gallon of waste-
water.  Figure  7 gives Fritz and Helle's
(1978) estimates for cypress strands for
                            Legend
                  Estimates,
               Sutherland (1978)
                             200,000 gpd facilities. Sutherland's esti-
                             mates for comparable size facilities are
                             included, using a capital recovery factor of
                             0.1.  Data are in reasonable agreement
                             with their estimates.  Thus, from a cost
                             viewpoint, wetland treatment looks attrac-
                             tive for  small  communities with  appro-
                             priate land/wetland availability.

                             References
                             Fritz, W. R. and S. C. Helle. 1978. Cypress
                               Wetlands as a Natural Treatment Method
                               for Secondary Effluents.  In: Environ-
                               mental Quality Through Wetlands Utili-
                               zation, MA Drew, ed. Coord. Council on
                               the Restoration of the Kissimmee River
                               Valley,  pp. 69-81.
                             Sutherland, J.  C. 1 978. Investigation of
                               the Feasibility of Tertiary Treatment of
                               Municipal Stabilization  Pond  Effluent
                               Using  River Wetlands  in Michigan.
                               Report to NSF, Grant # NV76-2081 2.
                              Data
Maple Rapids, Ml
7,000. — Deckerville, Ml




800



600


400


200



n
Edmore, Ml
Maple Rapids, Ml
Marcellus, Ml
Onekama, Ml
Rosebush, Ml
Scottville, Ml
St. Charles. Ml
Westphalia, Ml
~

HL 0
B

L MR^
_ B x-
QSC
Bw
(8 R B D
B S i
QAG
QD
Of
O/W?
QM
QO
QR
QS
QSC
QW

M
Q
x-
^





i
Houghton Lake, Ml B HL
Bellaire. Ml B B
Vermontville, Ml S V
Unnamed, Ml B SU
Drummond. Ml B D 0 ^
Listowell, ONT B Z. ./•''
Humboldt. SASK B J .,
Riverside, IA B fl ^
W ^ QD
Q ^
^
^
-X "
^ O
QAG





1 i i i i
 Figure 5.
              2.3        4       5
                 Pond-Wetland Distance (Miles), D

Wetland capital costs versus wetland distance from pond/adapted from Sutherland,
1978). (See Table 1 for site symbol identification.) Pipeline costs predominate.

-------
                             Legend
                  Estimates,
              Sutherland (1978)
                               Data
  «s
  s.
 2
 <*
 o
     15
     10
Maple Rapids, Ml
Deckerville, Ml
Edmore, Ml
Maple Rapids, Ml
Marcellus, Ml
Onekama, Ml
Rosebush, Ml
St. Charles, Ml
Westphalia. Ml
_SO s
8 HL
g V
B SU ,
QAG
OD
0£
QMR
QM
00
QR
OS
QSC
OW
Houghton Lake. Ml B HL
Bellaire. Ml B B
Vermontvil/e, Ml S V
Unnamed, Ml B SU
Drummond, Ml B D
Listowell, ONT B L
Humboldt, SASK B J
Riverside, IA g H
O
0
___ 	 OD
Figure 6.
      12345678
                  Pond- Wetland Distance (Miles)

Wetland 0 & M cqsts versus wetland distance (adapted from Sutherland,  1978)
(See Table 1 for symbol identification.) Line is for Sutherland estimates.
   D. E. Hammer and R. H. Kadlec are with Department of Chemical Engineering,
     University of Michigan, Ann Arbor, Ml  48109
   William R. Duffer is the EPA Project Officer (see below).
   The complete report, entitled "Design Principles for Wetland Treatment Systems,"
     (Order No. PB 83-188 722; Cost: $22.00, subject to change) will be available
     only from:
           National Technical Information Service
           5285 Port Royal Road
           Springfield, VA 22161
           Telephone: 703-487-4650
   The EPA Project Officer can be contacted at:
           Robert S. Kerr Environmental Research Laboratory
           U.S. Environmental Protection Agency
           Ada, OK 74820
                                                                                      . S. GOVERNMENT PRINTING OFFICE: 1983/659-095/1948

-------
                               Legend
                     Estimates,
                  Sutherland ft978)
              Maple Rapids. Ml Q AG
                     Houghton Lake, Ml
                                   Bellaire, Ml
                                   Vermontville, Ml
                                   Unnamed. Ml
                                   Drummond. Ml
                                   Listowell. ONT
                                   Humboldt. SASK
                                   Riverside, IA
Deckerville, Ml   QD
Edmore. Ml      Of
Maple Rapids. Ml 0 MR
Marcellus, Ml
Onekama, Ml
Rosebush, Ml
Scottville, Ml
St. Charles, Ml
Westphalia. Ml
                                                                           10.0
                                   Length of Force Main (Miles)
   Figure 7.
Incremental cost estimate lor advanced secondary wetland treatment (adapted from
Fritz & Helle. 1978). Curves based on 0.2 Mgd. No land cost for $1000/acre.
 (See Table 1 for symbol identification.)
United States
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                     Information
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