PB83-107466
The Use of Wetlands for Water Pollution Control
Association of Bay Area Governments
Berkeley, CA
Prepared for
Municipal Environmental Research Lab.
Cincinnati, OH
Sep 82
U.S. DEPARTMENT OF COMMERCE
National Technical Information Service
NT1S
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EPA-600/2-82-036
. September 1982
PB33-107U66
THE USE OF WETLANDS FOR HATER POLLUTION CONTROL
by
Emy Chan
Taras A. Bursztynsky, P.E.
Association of Bay Area Governments
Berkeley, California 94705
and
Norman Hantzsche, P.E.
Yoram J. Li twin, Ph.D.
RAMLIT Associates
Berkeley, California '94705"
Grant No. R-806357
Project Officers
Richard Field -.,
Dulcie Weisman
Storm and Combined Sewer Section
Wastewater Research Division
Municipal Environmental Research'Laboratory (Cincinnati)
Edison, New Jersey 08837
MUNICIPAL ENVIRONMENTAL RESEARCH.LABORATORY -
OFFICE OF RESEARCH AND DEVELOPMENT
U.S. ENVIRONMENTAL PROTECTION AGENCY
CINCINNATI, OHIO 45268
.' KPHMUCCDBT ~ ' '
i NATIONAL TECHNICAL
INFORMATION SERVICE
Ui OfPARIXtKI OF COHMHCt
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TECHNICAL REPORT DATA
(Pteale read Inttructions on the revene before completing!
1. REPORT NO.
EPA-600/2-82-086
2.
3. RECIPIENT'S ACCESSION-NO.
P38 3 107466
4. TITLE AND SUBTITLE
THE USE OF WETLANDS FOR WATER POLLUTION CONTROL
S. REPORT DATE
September 1982
6. PERFORMING ORGANIZATION CODE
1. AUTHORIS)
Emy Chan, Taras A. Bursztynsky, Norman Hantzsche
and Yoram J. Li twin
8. PERFORMING ORGANIZATION REPORT NO.
B. PERFORMING ORGANIZATION NAME AND ADDRESS
Association of Bay Area Governments
Hotel Claremont
Berkeley, California 94705
1O. PROGRAM ELEMENT NO.
11. CONTRACT/GRANT NO.
R-806 35 7
12. SPONSORING AGENCY NAME AND ADDRESS
Municipal Environmental Research LaboratoryCin., OH
Office of Research & Development
U.S. Environmental Protection Agency
Cincinnati, Ohio 45268
13. TYPE OF REPORT AND PERIOD COVERED
Final 6/78 to 5/81
14. SPONSORING AGENCY CODE
EPA/600-14
13. SUPPLEMENTARY NOTES
Project Officers:
Richard Field"(201) 321-6674
Dnlr-io
16. ABSTRACT '' : ;
Wetlands such as marshes, swamps and artificial wetlands, have been shown to remove
selected pollutants from urban stormwater runoff and treated municipal wastewaters.
Wetlands have produced reduction in BOD, pathogens, and some hydrocarbons, and excel
in nitrogen removal. They have been reported to act as sinks for trace metals,
phosphorus and suspended solids. Physical pollutant removal mechanisms in wetlands
include sedimentation, coagulation, chemical filtration, volatilization, adsorption
and chelation. Vegetative mechanisms include absorption through roots, stems and
leaves, filtration and chemical transformations in the plants. Chemical transfor-
mations of some water borne pollutants also occur in sediments and the water column as
a result of anaerobic or aerobic conditions, the presence of catalysts and reactive
substances, and with the aid of microbial action. Although individual plant
species have been studied for their pollutant removal properties, the interaction
of numerous plant and animal species in pollutant removal in a wetland is not
well understood.
17. K£Y WORDS AND DOCUMENT ANALYSIS : ;
a. DESCRIPTORS
Drainage, Water pollution, Waste treatment
Surface water runoff/Water quality,
Overflows, Stormwater, Hydrology
13. DISTRIBUTION STATEMENT
Release to public
b.lDENTIFIERS/OPEN ENDED TERMS
Wetlands, Treatment,
.State-of-the-Art Review,
Urban runoff, Stormwater
19. SECURITY CLASS (This Report/
unclassified
2O. SECURITY CLASS (Tiuipafe/
- unclassified
c. COSATl Field/Group :
21. NO. OF PAGES
276
22. PRICE
EPA Form 2220-1 (»-7J)
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NOTICE
Mention of trade names or. commercial products does
not. constitute endorsement or. recommendation for use.
11
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FOREWORD
The Environmental Protection Agency was created because of increasing public
and government concern about the dangers of pollution to the health and wel-
fare of the American people. Noxious air, foul water, and spoiled land are
tragic testimony to the deterioration of our natural environment. The com-
plexity of the environment and the interplay between its components require
a concentrated and integrated attack on the problem.
Research and development is that necessary first step in problem solution
and it involves defining the problem, measuring its impact, and searching
for;solutions. The Municipal Environmental Research Laboratory develops
new.and improved technology and systems for the prevention, treatment, and
management of wastewater and solid and hazardous waste pollutant discharges
from munic.i.pal and community sources, for the preservation and treatment of
public drinking water supplies, and to minimize the adverse economic,
social, health, and aesthetic effects of pollution. This publication is
one of the products of that research; a most vital communications link
between the research and the user community.
Application of municipal wastewaters and polluted urban runoff to wetlands
has the potential for low-cost water quality protection in numerous com-
munities. The multiple uses,of wetlands, such as recreational facilities,
wildlife and fisheries enhancement, recharge of.ground water, and-water
quality renovation, offer justification for implementation where single-
purpose, energy intensive, conventional treatment facilities may not be
supported. The development of appropriate design and operating criteria
for wetlands treatment systems is of prime importance to the success of
this concept.
Francis, T. Mayo
Director
Municipal Environmental
Protection Agency
iii
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ABSTRACT
Wetlands, such. -.as; marshes , swamps and. art i ficial wetlands , have been
s.hown to 'r?emo.ve..s'e-1e. .stems a-nd -leaves ;: -filtration and chemicaT transformations
iin r^the! p.laryt.s . "Chemtcal transformatiO'ns of sbme;;waterbo rhe po 1 1 utants
a^^o^O'Ccurif^nV'the ;^ed^i;-ment' Layers- '-a r the .water co-lumn as a result of
anaepo;bic-; or^-aerobic conditions, -the presence. of catalysts and reactive
substances,: and iwith the -a-id of microbial action.:
Althp.ughri:nd/i;v;i,dual p-lant species have been studied for their pollutant
nemo:.vsaVj(:pro:0er:t~ies , the interaction of numerous plant .and animal species
:in-;-po;l;1;uit-ant- removal An a -wetland is^ not well understood. Management of
^wetrland'tv^get-^t^ve .s-ystems , to optimize pollutant removal requires
f urthe r:Y^ny,:es;fci3a tio n .
'Furt:heri;r?.e.sfiai?ch:?nee,ds:itO"be' conducted ?on long-term impacts ,., to wetlands ,
'bio-accumuilfatiion' oft it-race metail s i the interac-tion o f individual po 1 1 utant
:r^emp;val!;«vme;Cih'an^»s;ms- -i n v-a-p i=o us- we-t lands systems, and management
techniques" ;:fo ^wetlands: used as treatment systems.
.TV
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TABLE OF CONTENTS
Page
Di scl aimer "i ^
Foreword iii
Abstract ...... iv
Tabl e of Contents v
List of Figures......... ix
List of Tables ... x
Acknowledgements. xii
: 1. INTRODUCTION .,..:.. .1
Overview and Objective.. 1
Background.. ; 1
Report Format.. ...... ............ 2
Summary 3
Literature and Practices.,., ... ..... ........ 3
Wetlands Treatment of Wastewater..'.' 3
Physical and Chemical Removal Mechanisms in Wetlands.. ... 5
Vegetative Treatment Systems 5
Hydrologic Practices 7
Conclusions. 8
2. CLASSIFICATION OF PRACTICES.....' ........,..........'.,.!.... 10
Definitions and Concepts 10
Wetland Characteristics 10
Upland Characteristics 14
Vegetative Systems-for Wastewater Treatment.........;............ 15
.Natural Wetland Treatment of Wastewater. ....,........>........,.. 15
Artificial Wetland-Treatment of Wastewater................... 16
; Upland Treatment of Wastewater......."........................ 18
Vegetative Systems for Stormwater Treatment.,...................... 20
',.' Wetlands Treatment of Stormwater........................... ...21
.,'; Upland Retention and Treatment of Stormwater; .......... .,22
References......... i....... .........,;.......;.. 26
3. WASTEWATER CHARACTERISTICS..................... J.......;".:. '.;,'.'..'." 31
Municipal Wastewater Characteristics ...^ 31
Raw Sewage 31
Treated Wastewater 31
Trace Elements in Municipal Wastewaters.......... 34
Wastewater Particle Sizes... ....'...... 34
Fl ow. ....... 34
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. ' : : ;,.' -TABLE'-OF -.CONTENTS ' :
(continued)
' ,-.. ... .....' ,.-.-.-;" ' ... -.-.-. '-.= -. ' . . - - -Page
Stormwater - Runoff . ......... ........... ..... ... ...... ----- . . . . ----- ...- ^
Ur-ban-'Runoff ........... . ........ . .:. . ..... ....... ............. 39
iRuraf ?Runof f ... . . ..'. ..". -------- . . . . . . . ...... . . . . . > ....... ..... ------ 43
' \Trace. £ laments :'in Urban Runoff....... ...... ...... ---- . .. . . ---- 43
:Hydrocarbons 'in Urban .Runoff....;;... ----- . ...... ............... 43
.Urban vStormwater Particle1 Size. . . . ..... ------------- . ........... 46
Urban -..Runoff Flow Characteristics. ... . ..... . . ...... -------- . . . . ..... 49
References. ..... ..... .. .. ....... ..... ..... ..................... ............... . . 52
4. :.PHYSICAL'to "Atmosphere -------- ..... ... ... ------ .... . . ..* ...... ....... 55
Sedimentation. ...... . . ................ ...... . ...:.,... -.-.. .... . . ..... ............ 57
./Sedimentation Theory... .:.-..-....; ......... ..... ....... . *. . .... . .. 57
sedimentation pf--.Rb,lTutia'nts.- ..... ............. ..... ... ..... ... 58
Emuisif ication. ... .... .... ...... . . . . .......... ...... . ...... . . . . . ..... 58
........... ;..;.i,i .. ......... ...... ... ...... ..... ......... . . ......... 59
Ret^bleum and Other Organic Compounds. .. . ... . . ..... ... ....... ... CO
';:Ammontum. ./...../..,. i ....... .. ..;.... .................... ..... 61
';;Phosphorus. ........ . ...... ... . ...... . . .... ;. ..... . . . ..... . ...... . 61
vHea.yy Metals,., ...... ......... ....... ...... ... . . ... .......... ...... .. ....... 62
:; Bacteria -and, Viruses. .... -------- ... .:.-... ..... ......... , ------------- . ... . . 62
iGhel'atiorv. --------- ,..". . ..... ... ------ ,. ........... ....... ...... . ..... ..... . . ; ------- 62
^PJreci.pl£aMon ?and; .Dissolution. .,.,.... . ........ ....... .,. ........... .... .;.,.. 63
;.OxixJa't|onirahdyReduction;. ..... ^.:. . '-.'. .V; . ... .-...^"... . ... .... ------ .; . . 64
' ... . ....... ../... ...,, ,,v. . . . .....,...>.... .... .-... . . ...:...... . . 64
'. iv.:...-. . ....... . . ... ...".-'^,. .-.;. .'. ...-. .-...-. ..; ; V. ... .:. ... *.;...-. .65
... ...... .'.....; ;..;......;..............;.. . 65
. > ..'.....-..........".'..-'.... .,-.....-. .- ....... . 67
5.-:. BIOCHEMICAL :ROLLUTANT REMOVAL MECHANISMS IN VEGETATIVE SYSTEMS, . . 73
: ;PoHojtant jUptake 'Processes . . . ..... . ...; . ............ .,.,. ... ...... .: --------- 74
:Uptake, through Plant^Soil Interface ------ .... ... ., ...... .... . _____ ..... 75
.Uptake,-thr,oii'gh P,lant--Water Interface. .......; _________ ...... .. --------- 76
Tr.ans1.ocat.ion through Plant Vascular System ..... ..... .. . .. ........ 76
Differential.. Uptake .vs. Nonspecific. Uptake. ..,. _______________________ 76
.Uptake, and: Immobilization by the Litter Zone. . . . ...... . . ------- 77
'..Adaptation Mechan-ismS; ..... .. . ______ ., . ___________ . __________ ...... ........ 77
'/Anaerobic Respiration* ...... ... ... .... . . ...... ---------- . ----------- ...... 77
Specialized Plant Functions . ...... ............... ---- . ---------- 7.8
; Nutrient Cycling Related to Wastewater Renovation.. ...... ........ 79
Nitrogen Cycles in Vegetative Systems........... ---------- ....... SO
Phosphorus Cycles in Vegetative Systems. ......... ...... ...... 85
vi
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TABLE OF CONTENTS
(continued)
Page
Uptake and Removal of Trace Elements 92
Emergent Aquatic Vegetation 97
Floating Aquatic Vegetation 101
Submerged Aquatic Vegetation.. 103
Uptake and Removal of Other Pol 1 utants 106
Boron Uptake, 106
Organic Compounds 107
Uptake of Biocides 109
Bacteria and Viruses.. > ........ 110
Other Water Quality Parameters 110
References , .... 114
6. HYDROLOGIC PROCESSES. . .............. 133
Wetland Hydrology - Characteristics and Processes. ...... 133
Watershed Hydrology. , ,, * 133
Geology .'... 134
Hydrologic Factors.. .... .. .....:.. ..,.,......,... 134
Ecosystem Hydrology ..... ...... 138
Hydrologic Management of Wetlands for Pollutant Removal.. 142
References 146
7. CASE STUDY REVIEW 151
Use of Wetlands for Wastewater Treatment... 151
Northern Freshwater Marshes..........i...........,;.......:v:. 152
Southern Freshwater Marshes... 153
Northern Peatlands.......... ... ............... 155
Tidal Wetlands 156
Artificial Wetlands..................'.. .......... .... 157
Aquatic Plant Systems - Water Hyacinth. ., 159
.. Land Treatment of Wastewater. ...,:..,........ i........ '165
Wetlands Treatment of. Surface Runoff.. .......................... 165
Case Studies , 165
Summary of Surface Runoff Treatment. ....,.;....... 167
Upland Retention, and treatment of Surface Runoff ..... .... :. 17T
Retention/Detention Controls.. 172
Grassed Waterways .. '' 3
References ' - '76
8. GUIDELINES FOR WETLAND SELECTION AND DESIGN. 182
Introduction 182
Selection of Wetland. 182
vii
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TABLE OF CONTENTS
(continued)
:.. ' - .- . ' Page
., {Design Facto.rs.............. v......,.;.- .....' 184
": ;T:ype':pf''Wetland'....................;... . ]g4
Hydrolog.ic System 185
iVegetative System ] 90
Seasonal Factors . 192
.Nature of .Polluted .Water... 192
'.. :ioad:i;ng ^Rate. ...... ............ 195
" Targ.et Ro1-1,utah;ts...................... ..'.. 196
. Cqnt|ng.enci,es"...'..'....'... . 193
' -Secondary Ehvrroninental impacts. 198
' ""D-ts'eas.e Vector Organl sms 198
Nuis,ajice Organisms. i99
.Odors....".'.......-.V..-.1........... ........ ,...>........'. 199
;Fog Generation. 202
:Be4ef,ic"ial -Secondary impacts ,. 202
Maintenance..'..'.".".'............. '. 202
' .GosJts.......... V. 204
Inferences'. '.'/...;.....!'..,.'<..... 206
9., .MONITORING AND RESEARCH NEEDS.... 210
Wetlands- Inv.entpry.. 210
.' .Moni.tojfcfng /..'.".'...!....'.............'..'. 211
^Resefrcli ''issjiei". '. .................;. 211 .
"" V^getatiye/Bloipgical System......... ., .... 211
Hydroiogic .System ;.'.................-... v : 212
S;yitem .Perfppance....'.....; ....... ...... 212
fhepry of W£tlands Treatment...................... ........ 213
^ 213
!.................................... -;". ....-.-' 214
, w
A ,..._. A-l
y^getation Typfss ,:.........;. A-l
: ,,Refe'Ke'q<:es. .^."."..'.'....... i..... i ..... A-l 2
APPENDIX B.. ...:..,..'.. B-l
AR.PENDIX C C-l
viii
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LIST OF FIGURES
Page
Figure 1. Methods of land application 19
Figure 2. Classification of particles found in water 37
Figures. Variations in municipal wastewater flows 38
Figure 4. Typical small watershed hydrographs 51
Figure 5. The nitrogen biogeochemical cycle...... .. 81
Figures. Phosphorus biochemical cycle 90
Figure 7. Wetland relationships to the principal zone of saturation
(hydrologic position) 136
Figure 8. General conceptual model of the role of hydrology in
wetland ecosystems.. 139
Figure 9. Comparison of renovation potential of two hypothetical
wetland systems ...188
Figure 10. Alternative wetland arrangements designed for increased
nutrient retention which might be possible in constructed
wetland areas.................... 189
Figure 11. Effect of BOD loading on BOD removal in water hyacinth
systems .;' 194
Figure 12. Effect of BOD loading on BOD removal in marsh and peat-
land systems.. ........195
Figure A-l Emergent Aquatic Vegetation A-4
Figure A-2 Floating-Aquatic Vegetation ..; . ...A-8
Figure A-3 Submerged Aquatic Vegetation A-10
Figure .B-,1 Existing State .and .Local .Wetlands Surveys..:.. .Brl
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LIST OF TABLES'
Tab-He }'-.,.' Clas-sdficati:bn- of 'Natural Wetland Systems.. . 12
TabitepZ.. Ar*i#ifcia3v Wetlands Used-for?the Treatment of 'Wastewater or
Stormwaten;y. * 13
Tab-lie; 3.:. Composition; of. ;Raw- Municipal. Wastewatersv. 32
Table 4. Compo.sn.tion .-of Treated Municipal Wastewaters-. 33
Tabfe 5>. Trace:'.Elements in- Raw- Municipal - Wa-stewater-v...... 35
Tablfei&.-.;: Tr.ace-£1ements. in; Municipal- Effluents..... 36
Tabiie:7.> Size.:Distr4bution:-of-.Wastewater 'Particles...... ... . 37
Table* 8:.;. Ur,b,an:. Stormwater- -and; Combined Sewer Overf1Ow QuaVity. . 40
Tablet.9.v Compan,i-son;>of,'Urban; Runoff by: Land -.Use.-. ., 41
Tabfe 10i, San^FranciscoviBay! Area>- Urban .Runoff Monitor.ing- Results
Grouped:.:by Predominant. Land'Use ;........ 42
Tabfe^ll ..' Agricultural;. Runoff Character, istics........... *.. ............ 44
Tablfe; 12L Trace^E-liements ihV:Urbanv Runoff'.'; *-............,...-;...' 45
TaMie^3i^Tra;C&£l;ements^in; Stormwater- So.ln'dSi .;...; ^ 45
Tab,M i;4!.r HydRp:Garbbhs;!-in Urban Runoff. 47
Tab.l'e; 15; Size;,D.istribution of Urban Stormwater Particulates. 48
TabHJe;:T6u Annual.\Distr;ibut,1on ,o,f Rainfaill Events...,. 50
Tablle-17; Physieal;.. and- Cheni'lcal;. Pol 1 utant Removal Mechanisms in Wet! and
and;vAquat.ic Systems.. 56
Tab.lie:-':!8...Nitrogen;,;Remov.a.l Potential, of Emergent Aquatic Vegetation..... 86
Tablie; ^9^ Nitrogens Removal- Potential of Submerged Vascular Plants 88
Tabilie- 20U Nictrp.gen;-Uptake Rates>of Emergent Aquatic Plants 89
Tabi;e;'.:2:li: PHpspho;rnjSi: Removal- Potential^of Emey?,gent -Aquatic Vegetation... 93
Tab:l;e'..,2:2;.l Phosp^Offiu-s^Remov.aiT,!Potential. of- Submerged/Vascular PI ants 95
TaWie: 23v-Phosphorus Upta-ke Rates-of Emergent Aquatic Plants,..'.......... 96
Tabil!e-.24;i:iHea^y/.'Metal;.; Removal Potentials of Emergent: Aquatic Plants
-"'"' :; '$<$;< Coi,i-Cu^^Fes -Hg);; ...;. 98
TabM 25\,vHea;v.y/;.Met^.Removal,Potentials of Emergent .Aquatic Plants
':-:.; ;; .: CMfJ'v-Mo^ftfcW; Zn^;..-....*;.-:.,.;...........,........;.,,.'..:..... 99
Tab(Te^26:.,- Heaiv^Mefa^- Content, of,Floating Aquatic Vegetation;........... 102
Ta-bifeV-2:7;:V"-Hea'V^vWeta';lifiembV:a'TxPoten-tta:l:S of ;Submerg;ed-VascU'lar Plants,.. 104
TabUIe;- 28,.: Sig^i;earit; Wet 1 and^ Water.shed. Factors-. 135
Tabilie 29;^,.;WetAandpEcasystem-:-Responses, to: Various,,.Hydro-logic Factors;,... 140
TablV 30-;' Relia'tionshi'p of Hydrolog,ic Factors to; Pollutant Removal in
Wetiknds;........ 143
Table; 31 .: Obs'epyedr- Pol lutant, Removal. Ef f ect.i veness. of Wetl and - Wa stewater
Trea-tment Systems.,. 160
Tab}e 32. .Observ-edi-Poinutant' Removal Effectiveness ,of Wetland-.Stormwater
Treatment:Systems.... 168
Table 33. .SimuilateduAnnual'Pollutant Removal Rates..for Detention Basin
and On.-Site'. Retention/Detent ion Control s 172
Tablie-; 34. ^ Performance, of Retention/Detent ion Controls, Orange: County,
Florida., 174
Table 35. Reduction in.Water, Sediment and 2,4-D in the Waterway 173
x
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: . ;LIST OF TABLES . ' .
, (continued)
Table 36. Applied Pollutant Concentrations., 193
Table 37. Recommendations to Prevent Mosquito Problems Associated
with Freshwater Marshes 200
Table 38. Wetlands Development and Management Guidelines for Waterfowl
Enhancement 203
Table 39. Comparison of Wetlands and Activated Sludge Costs 204
Table A-l - Emergent Vegetation Types, Characteristics and Environmental
To!erances A-2
Table A-2 - Floating Vegetation Types, Characteristics and Environmental
Tolerances A-7
Table A-3 - Submerged Vegetation Types, Characteristics and Environ-
mental Tolerances .... A-9
I
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ACKNOWLEDGEMENTS
Thrs-reportvwas.::made .possible by a-grant from the Environmental Protection
Agency,^Municipal Environmental Research-Laboratory, .Edison, New Jersey.
The ^authors'acknowledge and appreciate :the ass-istance and coordination
provided-byiMr.-Richard Field, Chief, .Storm and Combined Sewer Section,
EPA Municipal 'Envrironmental Research Laboratory, Mr. Anthony Tafuri,
Mr. .Douglas'-Ammoa, xand Ms. Dulcie Weisman, Project Officers..
Special -.than-ks for-program assistance contributions and editing are owed
to .Dr.--Peter;P..'Russell and Mr. Douglas ;Detling,, ;ABAG, and Mr. Joel
Sabenorio,;-jRAMLIiT. Associates.
xn
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SECTION 1
INTRODUCTION
OVERVIEW AND OBJECTIVE
Strong evidence exists to suggest that wetland and upland vegetative
systems have the ability to degrade and eliminate various water-borne
pollutants. Information on the subject, however, is scattered over a
wide range of technical disciplines, much of it the result of
investigations undertaken only within the last five to ten years.
Consequently, technical guidance is lacking on potentially useful
management practices for wetlands. Prior to the adoption of policies
for utilizing the natural treatment functions of vegetative systems,
there is a need to define the current state of knowledge on the subject.
This study was undertaken specifically to address this need. Its
objective is. to: summarize relevant findings on the topic of wetland
treatment of pollutants and to guide users to pertinent literature.
sources .for more detailed analysis of specific issues. :,. ,.
BACKGROUND
Over the past decade major steps, have been .taken to ..control the
discharge of point sources of water pollution. Mast apparent is the
extensive effort to upgrade a.nd construct wastewater treatment
facilities. This has occurred under the Federal Water Pollution Control
Act Amendments of 1972 (PL 92-500) and the Clean Water Act Amendments of
1977 (PL 95-217). Also important to improving water quality are efforts
to control nonpoint sources of pollution usually associated with
stormwater. runoff. Numerous studies under the Clean Water Act's Section
208 water quality, planning program strongly conclude that water quality
goals will not be met in some areas unless specific actions are tajcen to
control these nondiscrete and widespread sources ofpollution.
The technblogy, and management 'too,! s-for control! ing : surfacei 'runoff
pollutants have advanced considerably as a result of the 208 program and
related research activities. However, for a variety of reasons,.
principally financial, it appears unlikely that concerted local efforts
to implement nonpoint source controls will occur unless these programs
can be related to other environmental issues and public needs. . .
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Qrie'ipo-te>itTally' attra.ct'i ve management option for addressing surface
runtivff pdllii$'ldri is to tie problem mitigatio.ri'
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(5) Pol-lutant Removal Processes in Vegetative Systems -
Review of waste-processing capacity of vegetative
. systems, as influenced individually and .collectively by
characteristic plant types, soil properties and
biochemical processes.
(6) Hydrologic Practices - Examination of hydrologic
processes and characteristics of wetlands.
(7) Literature and Case Study Review - Summary and
comparative review of different types of wetland systems
and their influence on water quality and treatment of
point and nonpoint source wastewater flows.
(8) Design and Management Guidelines - Summary of wetland
design and selection factors common to most situations
and specific hydraul ic/hydrologic management practices
pertaining to pollutant control in wetland systems.
(9) Monitoring and Research Needs -Identification of
monitoring needs and research issues, to promote a..better
understanding of the treatment processes and potential
for .wetlands use under specific conditions.
SUMMARY
Literature and Practices
Wetland and upland vegetative systems have, attracted attention as
natural sinks for contaminants and as potential components, for
wastewater and stormwater treatment systems. The greatest amount of
investigation and literature pertains to the treatment of municipal
wastewaters. Promising findings have fostered scientific interest and a
handful of investigations into the effectiveness of vegetative systems
for the control of stormwater pollutants.
Wetlands Treatment of Wastewater
o Wetlands Treatment of Municipal Wastewater
Wetlands occur in'a wide range of physical settings at .the interface of
terrestrial and aquatic ecosystems. Because of this position, some
wetlands have been subjected to inadvertent municipal and industrial
wastewater discharges for many years. It is only in the past 10 to 15
years that attention has focused on planned use for wastewater
treatment. Promising results have been obtained with experimental
applications in various natural wetlands including:
o northern peatlands; , :
o cattail marshes; ...
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o ^southeastern .swamplands;
o cypress .domes;
o freshwater/tidal marshes. .
, Consolidation of results indicates that, in nearly alt instances,
wetlands .act to :reriovate or improve water qual ity to some extent."
Pol 1 utant-, removal efficiencies are extremely variable and questions of
treatment capacity and long-term wetland impacts are unanswered.
:Indi scriminant discharge of wastewaters to wetland ecosystems is not
advised.
o Artificial Wetlands for Treatment of Municipal Wastewater
The creation of artificial wetlands for treatment of wastewaters has
sbeen the subject: of experiments fo r both small and large-scale
applications in Europe and the United States, using different types of
vegetation .an.d .substrates. These systems .offer controlled environments
for testing and studying vegetative treatment of wastewaters. The
resulting data establ ish hydrologic and constituent .ba.l ances and assess
poll utant -removal capabilities for these systems. Examples of
artificial ^systems include:
o meadow-marsh-pond system (New York);
o .ponds with reeds or rushes (Germany and Holland);
o peat filters (Minnesota);
o mar sh> pond system- (California);
o seepage -wetland (Michigan);
' o -water 'hyacinth ponds (Florida and Texas).
researchers favor continued work with artifical wetland systems
vbecau.se .0 f the: hi gh degree of control and rel i ab i 1 i ty . The
'environmental enhancement they provide is an added incentive.
o Wetlands Treatment of Stormwater
:'F:ield investigation and research concerning the use of wetlands for
treatment of Stormwater runoff ^have been extremely limited. The few
studies .undertaken (a) exhibit 'great dissimilarities in the type of
\-wetland and Stormwater characteristics examined, (b) contain a very slim
data.'base from which to draw conclusions, and (c) encountered numerous
complications \in determining hydrologic components. Key investigations
ji nclude1- studies of :
o northern peatland (Minnesota);
6 cypress wetland (Florida);
o brackish .marsh (California);
o trigh. altitude meadows (Lake Tahoe);
o wetland detention basins (Maryland).
-------
In general , these studies revealed the following:
(1) .A wide disparity exists in nonpoint source pollution
removal capabilities of wetlands, particularly with
regard to nutrients; .
(2) The greatest consistency in pollutant reduction appears
to be for biological oxygen demand (BOD), suspended
solids and heavy metals;
(3) The nature of flow and seasonal factors are major
influences on pollutant removal capabilities in certain
wetlands.
Physical and Chemical Removal Mechanisms In Wetlands
Some investigations of the physical and chemical removal characteristics
of wetlands have been undertaken. Several removal processes that occur
in.natural.waters are likely to occur in wetlands. Many have not been
documented in marsh environments. Studies of rivers, lakes and oceans
have .been dominant in research. Nevertheless, a few general conclusions
can be drawn:
(1) A wide variety of physical/chemical pollutant removal
mechanisms occur in wetlands. Most commo.n are
evaporation, sedimentation, adsorption, filtration,
9chelation, precipitation, decomposition and absorption.
(2) Wetlands exhibit large .variations in type, climate and
ecosystem. The interaction and relative importance of ; "
physical/chemical pollutant removal mechanisms varies
significantly among and within wetlands.
(3) Studies of pollutant removal mechanisms in wetlands have
generally been piecemeal. Sufficient data have not been
collected to formulate a comprehensive theory of
pollutant transport and fate within a wetland system.
Vegetative Treatment Systems
Although the initial pollutant removal mechanisms in wetlands are
physical and chemical processes, plants can increase the overall
capacity of a system to retain or remove pollutants through interactions
with various anaerobic, and aerobic soil layers, water, and air
interfaces. In particular, plant root uptake of pollutants from the
sediment frees.more exchange.sites in the sediments for further
pollutant interaction and accumulation. The primary biochemical
pollutant uptake and removal processes in vegetative systems are:
(1) Uptake through plant-soil interface, via belowground
roots, rhizomes, holdfasts and buried shoots and leaves;
-------
(2)'~-'Upjii!k^1''through: plant-water interface, via submerged
. root's 'r'stems, shoots and' leaves;
(3) :'Transi6cati6n' through>'p1 ant' vascular system, from roots
to -stems? snoots";- leaves and" seeds during growing season;
(4-)' ;Dit;feVettt'ial pollutant' uptake, such as preferential
stpra'gppf trace contamiharits -in specific plant parts 'and
.preJfe'reWi al ' uptak:e/acc'u'mul at'ion of certain trace
elements',"
(5)" j!tof specific;, po'Tl utant' uptake'/ occurring' primari 1y as
pT;ahtV"ab'iorb 'large 'quant'iti'es of nutrients from water
and"'se'dimen'ts:;
(6)' -Upta'ke'an'd immobilization by plant litter zones, where
de'Vtt:, ;-but- 'not d ec"b"ni:po "s>e;d ,"
-------
o Uptake and Removal of Trace Elements
Wetland .systems can function as sinks for heavy metals and other trace
elements either through vegetative uptake and storage or through
immobilization in the sediment layers. The observed heavy metal removal
potentials range from:
(1) 0.001 to 0.38 kg/ha of cadmium, with highest removals in
Potamogeton crispus and Salicornia pacifica;
(2) 0.007 to 1.58 kg/ha of copper, with highest levels in
Justicia americana and Salicornia pacifica;
(3) 0.13 to 103.4 kg/ha of iron, with highest levels in Carex
stricta; .
(4) 0.026 to 1.01 kg/ha.of lead, with the highest levels in
: Salicornia pacifica and Phalaris arundinacea;
(5) 0.001 to 1.714 kg/ha of zinc with the highest levels in
Phragmites communis, Carex stricta and Scirpus lacustris.
Although pollutant removal potentials for floating aquatic vegetation
are not reported in kg/ha,^observed.uptake .and concentration in water
hyacinth (Eichhornia crassipes) are significant for some heavy metals,
particularly- cadmi urn, chromi urn, copper, lead, nickel, gold and
strontium.
Hydrologic Practices ., ,: ;-...'..
A clear knowledge of.the hydrogeology. is crucial for understanding the
wetland environment and assessing its .potential utility for assimilation
of water-borne pollutants. The lack of adequate, hydro logic information
has hampered the efforts of numerous researchers in their attempt to
quantify and evaluate the pollutant removal efficiency of wetlands.
In considering the application of stormwaters and wastewaters to
wetlands, the relationships between hydrology and ecosystem
characteristics need to be recognized. Factors such as source of water,
velocity, flowrate, renewal rate and frequency of inundation have a
major bearing on chemical and physical properties of the wetland
substrate which in turn influence the character and health of the
ecosystem as reflected by (a) species composition and richness, (b)
primary productivity, (c) organic deposition and flux, and (d) nutrient
cycling. In general, water movement through wetlands tends to have a
positive impact on the ecosystem.
-------
Hydrology -cp'nt'rol-s pollutant removal in -wetlands through its infl uence
.on processes 'of sedimentation, aeration; biological transformation and
soil ^adsorption. Critical Uhydro1o;gic factors are:
.0 , velocity and f Ip wrate;
p waster depth and fluctuation; .;
o detention time;
o circulation and distribution patterns;
o turbulence and wave action;
o seaso-nal and climatic influences;
o 'ground-water conditions;
o soil permeability and :ground-water movement.
;iV:ario:US .criteria and practices can be identified for hydrologic
.'management' of -wetlands for improved wastewater and stormwater treatment.
(1) Flow routing - Initial introduction ;awT subsequent
distribution of flow should attempt to maximize effective
';eO;ntact:between water and 'wetland soils arid Vegetation.
(2) Water level maintenance - Manipulation of water levels is
a -useful means of enhancing pollutant -removal by '
vegetation and soil. Regulation of levels must take into
.account competing ecosystem needs and the additional
nuisance problem of mosquitos.
(3) Inflow/outflow regulation -.Possible techniques might
/include inflow and containment of the "first flush" of
run6ffy\or retention storage .during spring runoff 'unti 1
.marsh -communities are functioning at higher uptake rates.
(4) .:S.easo:nal application - Where ipossible , -seasonal
:appT.icatioris of wastewaters and stormwaters might be used
for ;S,peci fie treatment or flushing purposes, taking; into
.eonsideration:
o bio To'gi.cal activity in the wetlands;
o avajlability rof dilution flows;
- p 'seasonal .uses and quality of downstream receiving
. ,; ' ''.waters- . '.-.' ,
(5) Infiltration - Maximum soil contact sho.uld be .emphasized,
'«with ^attention given to routing a-nd/or Bonding
Nwastewaters in areas of highest soil permeability.
"This -study reviews numerous reports of vegetative removal of water-borne
^pollutants and several studies of wetlands. The conclusions that can be
.drawn from this review, because of the nature of available literature,
-------
reflect only an initial interpretation of the reported literature.
Synthesis of these study results into a theory of wetland pollutant
removal systems is beyond the scope of this report. Perhaps it is
beyond the presently available information. Therefore, conclusions
drawn from this literature survey may have to be revised as further
research results and operating information are collected.
The conclusions are as follows:
(1) The majority of wetlands studied were able to receive
treated municipal wastewater and/or stormwater runoff,
remove certain pollutants, and produce satisfactory plant
growth. Pollutants removed or decreased included organic
wastes (as measured by BOD), nutrients, suspended and
volatile solids, and trace metals.
(2) The application of hydraulic controls and vegetation
management has the potential to improve wetlands removal
of pollutants.
(3) Wetlands remove water-borne pollutants principally
through physical and chemical processes that are
substantially augmented by biological processes
associated with wetland vegetation. , ;
(4) Wetland system stress was reported only in laboratory
studies and.certain field studies below municipal and
industrial discharges, where plants were exposed to
...... .excessive pollutant concentrations. Abatement or
reduction of pollutant loadings usually Ted to recovery
of wetland vegetation. - .'
(5) Further research should be directed at improving
understand!ng.0f how wetland systems assimilate
pollutants after initial removal.
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SECTIONS
CLASSIFICATIONIOF PRACTICES
The*.utilisation- o:fr-vegetative systems- for 'the .treatment of polluted
waters '-spans, a wide1'variety of practices. This- study considers wetland
anrd:-uipl a-nd-^v eg etat-ive^sy. stems us.ed for the -treatment -of -munici pal
wa'SitewaiteinS'-and surface runoff. Included- are both natural an.d
ar-.t-irf i,C'i alsly ;d.e;veloped systems which function in some manner to
ass/imnlate: -waters-borne :po 11 u tants'. Ih :c ta-S!S..i-f yi ng the various
p:r!aie>t'i'ce:S,, .attention -is given to; the. underlying; purpose(s), basic
cd:f)l:esv6f 'O'per.atip:n^; ah;d, ty-p..!" cal area's: or
Hf;to;r.::tos-exfam:ini-ng .-specific practices ^ it- is important to clarify what
const^tutesfwe.t'lrands^iand^uplands- and to-'distingui sh between natural and
i^ic;ian.J: vegetative /systems..-
:^CIiia pa otenii istjic s-. . . -. .- ;.' ' - " ' . ' ...
^ierm-?'' Weit'l'a'n.dfS^ ' i.s;:-a Te.Tata'-veVy .new-ides ignat ion -for marshes., bogs ,
swamps:;van:dfeother': 46'W-iTyi ng .Tand--dominated ;by; saturated. ,so:i 1 to nd it ions
[2-.1 3. ;,, .'Num'e^.'.i^s.^ef^
' Mo-stv;;'defi:nitiohS!. reflect' the> fundamental
^^^^^ . Co ward in
esMbl1-1st)ed,:the\5f^ to-; -be - used in
wet-lands.,:tnventor.y. ' :
^a re; :;! and stna'n;S:itxi:o-n;an j::bet:ween :±errestri a-T
-water 'table: is: usually at :or near
and;, is- -covered by iha^To'wi -water:. .- For
puEpo-ses/.ofj thits.t classification1 'wetlands must have.-one -or more
ofs".th'e;!:ifo:"l-To-w;ingsthree-'attributes-:. (l,).:at,.lea.st periodicany ,
the;>;l:ahdi.isupports predominantly- hydrophytes; . (2) the: substrate
. 1s>pr.edom-inant-Ty;-undrained-hydric:.soil ; .and (3) the sub:st rate
'; a h:dr-is 'Saturated with'i-water-'or' covered by shallow
season -of each year."
TO;
-------
o Natural Wetlands
Descriptions of the principal types of natural wetlands, according to
hydro logical factors, are provided in Table 1. Included are (a)
riverine, (b) lacustrine, (c) palustrine, (d) brackish, and (e) tidal.
The system characteristics, representative vegetation types and some of
the important environmental sensitivities are also shown. In this
classification system, based on Cowardin et al. [2-1], saline tidal
wetlands are represented by the estuarine system.
In general, systems with open stands of emergent vegetation and/or large
open areas allowing algal growth demonstrate the highest plant
productivity. Palustrine freshwater marshes with peat-filled bogs or
heavily shaded wooded swamps generally do not show as high a
productivity as other fresh and salt water marshes. Lacustrine marshes
are strongly regulated by the water level in.the system. Emergent
plants are limited to pond and lake fringes and generally do hot occur
where the water depth exceeds 1 to 2 meters. Floating and, submerged
vegetation typically occur in the upper water layers (1 to 2 meters
depth) where thick plant growth can reduce dissolved oxygen and
attenuate light, discouraging plant growth in the lower layers.
Brackish marshes often occur within salt marsh areas near -streams j'and
in many cases can be considered as a type of salt marsh. In Table. 1,
brackish marshes are identified as a separate category to represent
marshes subject to salinity changes but not influenced by tidal actions,
as in the case of salt pans and seasonal inland marshes.
o Artificial Wetlands : :: ; ; , :>; ,
Artificial wetlands are the result of establishing wetland vegetation
and the required hydro-logic' conditions in locations where they
previously did not exist. Examples might include the creation of ponds
and marshes for wildlife and aquatic habitat enhancement. Lowlands
converted for use as permanent stormwater retention basins are another
possibility. Trenches and ponds constructed specifically for physical
and biological treatment of wastewaters may also take on the form of
artificial wetlands. In many such cases, the substrate and vegetation
established are foreign to the immediate locale. Table 2 provides a
listing of some of the .principal types of artificial wetlands
encountered in this study.
All of these systems exhibit some of the basic ecologic features
presented earlier in Table 1 under natural wetland systems. Artificial
marsh systems function in a similar manner to riverine systems where
there.is ample circulation, an abundance of wetland vegetation, and
maximum interaction between water, vegetation, and sediments.
11
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TABLE 1. CiASSIFICATIOH OF NATURAL WETLAND SYSTEMS
Wetland system
System characteristics
Vegetation types
Sensitivities
Freshwater Har&lves -
Riverine (associated with
water channels-)
Freshwater Marshes -
Lacustrine (associated
with ponds and lakes)
Freshwater Marshes -.
Palustrlne (not confined
by channels or adjacent
to lakes)
Brackish Marshes -
(salinity > 0.4 pptb)
Salt Marshes - (subject
to tidal Influence) ' '
Water circulation
distributes dissolved and
suspended materials through
system. Good aeration and
light penetration, ,
Temperature/oxygen
stratification and light
attenuation can cause major
dtffereneees in top, middle
and bottom layers.
Circulation is Often poor.
Surface layer has thick
and/or porous deposits with
High organic content; Marsh
Is fed by subsurface
seepage/high ground water.
Marsh fed by seasonal
surface flows and/or
seepage; may also be subject
to tidal influences;, can
experience salinity
fluctuations; ; :
!1) wetlands hear streams
2) lower wetlands -
reversing flow
(3) lower wetlands - drained
only at low tides :
(4) upper wetlands -
inundated Only at high
tides r
Emergent plants - cattails,
reeds,, sedges, bulrush.
watercress; floating algae.
Floating plants - duckweed,
water fern, water primrose,
pondweeds and others.
Emergent plants - see
riverine system; submerged
plants.
Peat bogs, cypress, mangrove
and papyrus swamps -
vegetation types,often
specific to geographical
area.
Emergent plants - sedges,
bulrush, plckleweed,
saltgrass, saltbush.
Emergent plants-
plckleweed, cordgrass,
sedges, saltgrass.
Subject to sedimentation,
scouring and seasonally-
changing water levels.
Pollutant loadings vary with
watershed.
Closed or semi-closed
systems. Pollutants enter
food chain or accumulate In
sediments.
Isolation from open water
bodies (streams, rivers and
lakes) limits wa te r
exchange, forming potential
pollutant sink.
Evaporation can lead to
salinities of 60-80 ppt and
concentration of pollutants.
Salinity and sediment
interactions can trap..
pollutants; however, low pH
and oxidizing muds can
re-release pollutants to
system on a continuing
basis.
a. Derived from references 2-2, 2r3 and 2^4. :
t>. ppt, parts per thousand
-------
TABLE 2. ARTIFICIAL WETLANDS USED FOR THE
TREATMENT OF WASTOfATER OR STQRMWATER3
Type
Description
Marsh
Marsh-pond
Pond
Seepage wetlands
Trench
Trench (lined)
Areas with impervious to semi-pervious bottoms
planted with various wetlands plants such as reeds
or rushes.
Marsh wetlands followed by pond.
Ponds with semi-pervious bottoms with embankments to
contain or channel the applied water. Often,
emergent wetland plants will be pi anted.,in clumps or
mounds to form small subecosystems.
Wastewater irrigated fields overgrown with volunteer
emergent wetland vegetation as a result of
intermittent ponding.and seepage of wastewater.
Trenches or ditches planted with reeds or rushes.
In some cases, the trenches have been filled with
peat.
Trenches lined with an impervious membrane usually
filled with gravel or sand and planted with reeds.
a. Derived in part from reference.2-2.
13
-------
P6ndi$ysteins<,functiQn similarly to a freshwater lacustrine, system. The
typ£? of 'treatment depends on the design of the. basin. -Deep basins
without ^cultivated vegetation function as simple wastewater treatment
f a gl^oIrS sphere sedimentation, algal growth and adsorption to particles
'occur. With aeration, growth of microorganisms i s .promoted and
brefrfc-dowrof some organic material occurs. The same 'processes occur to
^a" lesser degree without aeration, due to -the presence of different types
.o-tfRfUtfoofsganisms. With the growth of submerged i-and floating plants
,such"_as duckweed and water hyacinth, contaminants can be absorbed
* through; plant metabolism. Primary productivity: and. sedimentation can
"occur,, at* .a hfgh rate in these systems, which leads to vpol lutant 'sinks
rfbrarfng in the vegetation and sediments. Since the '.water level in these
.system can-be controlled, the vegetation can 'be skimmed from the
-surface and harvested, and the bottom deposits can be scraped or dredged
Seepage .wetlands, and lined and unlined trenches fall roughly in the
category of palu'stHne systems. Water applied to these systems
3rgerte»»aTly does not exit as surface runoff but, infiltrates -through the
5!wetlatff
-------
metabolism and absorption. Chief factors governing the movement of
pollutants in ..these interactions are the soil pH, oxidation^reduction
potential (redox potential) and the mineral composition of the soil.
High pH and low redox potential lead to the formation of insoluble metal
complexes, which effectively prevent plant uptake of metals. As pH
decreases and the redox potential increases (a situation that can occur
in temporarily flooded soils), metal ions are released and available for
plant uptake. In alkaline soils, heavy metals can be immobilized as
precipitates. Soil reaeration is important for the maintenance of
physical , chemical and biological interactions. The cation exchange
capacity (CEC) governs the long-term accumulation of pollutants such as
heavy metals. For the protection of ground-water resources,
particularly where used for human or livestock supply, the maximum limit
of pollutant accumulation should be calculated for each soil type.
VEGETATIVE SYSTEMS FOR MASTEWATER TREATMENT
Although inadvertent application has occurred for many years in some
instances, .the planned utilization- of vegetative systems for. treatment
of municipal wastewater is a relatively recent innovation.. Described
here are the three principal categories of interest: (a) natural
wetlands ,.(.b.).arti ficial wetlands., and (c) uplands.. . .... '
Natural Wetland Treatment of Wastewater , .
The interest in utilizing natural wetlands for treatment of wastewater
effluent has emerged as a result of several factors:
(1) Public demands for more stringent wastewater effluent
standards; . -. ; .
(2) Rapidly escalating energy costs associated with
conventional treatment facilities;
(3) Recognition of the natural treatment functions readily
available in wetland ecosystems; .... .. . - :
i- " " ' .
(4) Appreciation o.f the aesthetic, wildlife and other
incidental environmental benefits associated with
wetlands preservation and- enhancement. .
In most cases to date, the primary objective has been to provide a
degree of tertiary treatment, mainly to meet nutrient removal
requirements. Discharge of secondary effluent to wetlands seeks to. take
advantage of natural treatment processes related to four principal
features of:wetlands [2-1]: . . .
(1) Dispersion of surface water over a large area through
intricate channelization of flow;
15
-------
, (2) Utilization and transformation of elements by
microorganisms; ' ... ,
(3) Physical entrapment through'so'rption in the surface soils . .
and1 organic litter; : .: ^ , ,^ ;; '--'.
(4) Uptake and metabolic utilisation by plants;
.1 ' '.,.-.,'.' t - . , . , ""'-''
Achievement" of water quality treatment standards, through t-he-use-of .
natural biological systems is found to offer.an .economically attractive
alternative-to conventional advanced' wastewater treatment practices
[2-2^2.5^2-61;. ,-
Possible "constraints or problems associated with the use of wetlands for
wastewater^treatment include the following: .
(1) Nutrient and organic loading capacities are unique to
; ; /, . Individual.-.wetlands[2-7]; "-.-..'.. ;
f2) Proximity to,"sources of wastewater effluent influences
.-.. ;.;^' , cost [2r5l;> -" . .'...'.-.- ;-" -.--. - .'.."..--.' ;-..- ';-.\. .
''"' >''"V* '- ..- -.:';- ;'."':;., '-' -. , .'. -" . '.- . ' ' ..-...- -..-,, '-, '
(3) Long-term ecosystem effects are largely unknown [2-2,
'.-'.-.-'/"'2-7"3>:-:/^ .':;:..-" "."'';: .. '- ' ' "'."". -:;;;:--: -.;. ;.
(4) Wetlands may provide breeding grounds .for disease and
insects, and may generate odors [2-2],
Experimentation with wastewater discharges to natural wetlands has
occurred -in mari'y different parts of the U.S. and .Canada. .Examples of
wetlands that have b'een examined for wastewater treatment include the
fo Ho wing:",-
^o cypreVS'dourefS'(Florida) [2-9, 2-10, 2-11]; v,
o northernipeat'lafids1 (Michigan, Wisconsin) [2-12,^2-13];
o catta'iV marshes (Wisconsin) [2-14, 2-15, 2-16];. ; "..-;
o freshwa'ter/tidal marsh (New Jersey) [2-17, 2^18];
o lacustrine marsh (Canada) <[2-19]; :'.::..
o swamp'Vands* (Canada) [2-8]; , -.-..- ;.
o,southern .freshwater marshes (Florida) [2-20,.2-21, 2-22].
" U « / ' ' - ^ .'-'-i: ::- '-;:--''''-';'; --' -,.--.
As is evident from this listing, a range of different...types-of-, wetlands
are^ under investigation. Some of the wetland, systems have been
receiving wastewater discharges for long periods o,f time while others
are-the'subjects of recently initiated pilot studies.
Atttttcla 1 itfetT'andXTreatment- of Wastewater -
The-'use:of artificial wetlands for wastewater treatment seeks to take
advanta;ge:o'f many;o.f the same principles that appl.y in natural
biological systems; 'but does so within a more controlled environment.-
16
-------
Small-scale wetlands have been created expressly for the purpose of
providing wastewater .treatment [2-23, 2-24, 2-25], while others on .a
larger scale have been implemented with multi-use objectives in mind,
i.e., using treated sewage effluent as a freshwater source for the
creation and restoration of marshes for environmental enhancement [2-26,
2-27].
The use of artificial wetlands for wastewater treatment is founded
largely on the work of Kathe Seidel and her co-workers at the Max Planck
Institute in Germany [2-23], Since the early 1950's, they have been
studying the wastewater treatment capabilities of plants established on
artificial substrates. More recent developments have included the use
of peat filters, floating plants (e.g., duckweed and water hyacinths),
and large-scale creation of wetland habitats. Artificial wetlands have
been studied for their capabilities to provide primary and secondary
wastewater treatment as well as for advanced or tertiary treatment.
They afford much greater operational flexibility than do natural
systems. Some systems are set up to recycle a portion of the wasteflow
and to direct the final effluent into the soil for recharge purposes
[2-25]. Others act as flow-through systems, discharging final effluent
to receiving waters [2-26, 2-27].
Possible constraints to the use of artificial wet! an.ds for' wastewater
treatment include: .
(1) Geographical 1 imitations of plant species. There is also
the potential that a plant species introduced into new
areas will become a nuisance or an agricultural
competitor; . ;. .
(2) Land-based treatment systems require 4 to 10 times more
land area than a conventional wastewater treatment
facility;
(3) Plant biomass harvesting is constrained by high plant
moisture content and wetland configuration;
(4) Wetlands may provide breeding grounds for disease and
insects, and may generate odors.
Examples of typical artificial wetland systems used for wastewater
treatment include the following:
o meadow-marsh-pond system (New York) [2-25];
o ponds with reeds or rushes (Germany, Holland) [2-23, 2-24];
o peat-filled trench systems (Finland) [2-28];
o peat filters (Minnesota) [2-29];
o marsh-pond system (California) [2-26];
o seepage wetland (Michigan) [2-27];
o hyacinth pond systems (Texas, Florida) [2-30, 2-31, 2-32].
17
-------
Theser examples show -a. wide geographical distribution and active interest
in a: range-Jo-f' w.e-t land vegetative systems. There are-currently many in
the* field! p.iromo.t-ihg . expanded uti 1 ization of artificial , rather than
natural; we.tland- systems [2-7,. 2 -1
f -Wastewater
Major- efforts have been made during the past several years , to advance
the.;practiee of utilizing upland soil and vegetation for then treatment
and .disposal of : various types of wastewater [2-33], In the U.S., the
use of "land? treatment! for municipal wastewater has:been increasing
steadily over, the-past. 40 years.. The increase is attributable to :
(1) Public' demands and pol icies calling for higher levels of
waste treatment and reduction of surface water
- discharges; .
'' (2) Recdvgn-i tion o f ' the resb urce- val ue- of wastewater; .
".../. particularly; in the -western states. : :
Land'vtreatment is a. versatile practice, in which a variety of processes
may-'bevused .to achieve -a' number of different objectives; Specific
purposes:; f6r- which land treatment of wastewater -has been employed
include-: :
o- water- quality protection;
o/wa.stewater- reclamation and reuse;
. o gr50:und~water recharge; .
Or,, nutrient'. recye-ling:;; : .
o cro'p.'piroduction:. /
Th'e* ppsin c.i pal, methad s.. o f Ta nd t rea tment "in common -use > a r e ; ( a ) ; si o w- ra te
,i n- systems are: designed to' precl ude any surface runoff of
appl ied^r, wa.stewater;; Sprinkle and surface- application techniques are
bo.th'icommo^ly-used..ih slow-rate : land treatment- systems;
18..
-------
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SLOPE 2-4%
EVAPOTRANSPIRATION
GRASS AND VEGETATIVE LITTER
OVERLAND FLOW
a
Figure 1. Methods of land application.
a. Source: reference 2-23.
RUNOFF
COLLECTION
-------
Geo.gr?aphi;ca:T1y.j.. sl;o:w*rate systems may be found in use in all climatic
regions, of the; U. S. The major distinctions a,re in the period and rates
p. f application; and, resultant storage requirements. Controlling factors
are soil cond.itionij type of crop or vegetation, and climate.
61 '-Rapid: Infiltration
In contrast, to slow-rate systems , rapid infiltration i's usually employed
independently of agricultural or landscaping operations. Wastewater is
applied1 to thick deposits of coarse, permeable soils, where it readily
percolate.s. through the soil, eventually reaching underlying
ground; water.. Although there, are exceptions, vegetation is typically
not used;. Physical, chemical and biological treatment of wastewater
occurs as? a- result of passage through the soil matrix. .
Application, of wastewater is accomplished by spreading in basins or by
sprinkling., Recovery of the percolated effluent, through underdrains or
well: fields: is; often, incorporated into such s-ysterns to achieve reuse
Odb^ect.i v/e'S> or to protect the quality of pa^ticularly^sensitive
ground.-wa.ter bodies. ,:
the use-of raipid iCfiT4rat.ron sys:tems is widespread in the U.S. The
primary .criteria dictating..feasibil ity are soil; and hydrogeological
compatibility. ;
o. Overl and Flow
Qv.eHian;d' f--l:o;w is a metho:d of land- treatment used on -relatively
:impermeabfe; so.il's. In: such/.-systems,, wastewater is, typically applied at
t:;he: top;, o.f gentVy., sloping, terrain and a/I lowed to flow across the
vegetated' sun/ace,.until it;-is: co.llected in runoff ditches some! distance
downslope;. TheK:coiiected. runoff is then available for reuse-or direct
dischargevto surface-waters., .:,. ',,,' .: ..-;.. ......
V'0>,e,ri:a:nd^.,fTb:yf:'-:(iia;V^.>.ipe-f.erped;;to,--as grass, filtration-) mainly relies upon
m^crobia.l and; plant activity in; surface soils and; a. dense- gra'ss cover
for reno:-vatiort:.of wastewater.. It has been used for secondary .treatment
as wel T; a:si to- ac'h;ieve: high Te.v.el s o f ri'itro.gen and B:OD removal ,.
comparab'le. to- conventiana,! advanced- wastewater treatment processes.
OyJer.land; flow. is:.'a»relatively, hew practice^ in the; tK S., although such
systems.,have been- in operation for several decades in-Australia. The
nro;stpromising results, have been with systems in-warm climates. Recent
work has/been undertaken to develop information concerning performance
and; suitability of over/land flow systems in cold regions-.
20
-------
VEGETATIVE SYSTEMS FOR STORMHATER TREATMENT
The primary objectives of stormwater management are to minimize
inconvenience, hazards and damage resulting from the accumulation of
stormwater runoff. The conventional approach has been to provide a
system of channels and pipes to carry away rainfall as quickly and
efficiently as possible [2-341. Because of secondary hydrologic impacts
and nonpoint source water quality concerns, traditional stormwater
drainage practices have been subjected to serious revaluation [2-35].
A major new emphasis is being placed upon the identification and
application of "natural" engineering techniques to preserve and enhance
the natural features of a site, and to maximize economic-environmental
benefit [2-34]. Natural engineering techniques are those which
capitalize on, and are compatible with, natural resources and processes
[2-34]. Foremost are the uses of wetland and upland vegetated areas for
detention, infiltration and treatment of runoff.
Wetlands Treatment of Stormwater
By nature, most wetland systems receive surface runoff from adjacent
lands and watercourse?. To varying degrees, this provides treatment of
runoff waters. In the past few years serious attention has been given
to capitalizing on wetland processes as a means of providing detention
storage and treatment of stormwater flows. The emerging interest may be
attributable to three factors:
(1) Increased knowledge and concern regarding the control of
nonpoint source stormwater pollutants; .
(2) Heightened interest and experience with natural
biological treatment systems for wastewater pollutants;
(3) Alarmed concern for preservation of this nation's
diminishing wetland resources.
Many wetlands have been receiving inadvertent discharges of stormwaters
for a number of years. To date, there have been only a few instances
where stormwater has been specifically routed into natural or
artificially-created wetlands for flood control or water quality
management purposes. Where the practice has been employed, consistent
reduction of BOD, suspended solids and heavy metals generally have been
shown. Stormwater treatment through wetlands encompasses three
categories:
(1) Systems planned primarily for flood control with
treatment as an incidental benefit;
(2) Systems planned and operated with treatment of stormwater
pollutants as a primary objective;
21
-------
(3) Existih'g wetland systems providing detention and
trea-trileht o.f stormwater flows as an unplanned, natural
function.
The factors responsible' for wetlands treatment of surface runoff are
largely the same as those noted previously in reference to wastewater
treatment. In principle, wetlands offer hydraulic resistance to surface
runoff flowing through them, resulting in decreased velocities and
increased deposition-of suspended .sediments. The large surface area
provided by surface soils and vegetation contributes to higher levels of
absorption, adsorption, microbial transformation and biological
utilization than normally occur in more channelized water courses
[2-133.
The utilization or creation of wetlands for stormwater treatment is
limited by several factors, including:
(1) Proximity of natural wetlands to sources of runoff
needing treatment;
(2) Seasonal and sporadic nature of stormwater runoff where
reliable water supply is needed for maintenance of
wetland vegetation.; :.. . . : ...
(3) High flows .and flushing action associated with runoff
events;
(4) Potential for creating nuisance vector and odor problems.
A variety of management practices have been suggested to overcome these
limitations and enhance the'overall capabilities of wetlands for
treatment of stormwater runoff. A detailed discussion of possible
measures, including techniques related to inflow/outflow regulation,
Water level manipulation and flow distribution, is .provided in Section
6. ; . .-
Examples of instances where wetlands have been employed, examined or
proposed for treatment .of stormwater include:
o northern peatlands (Minnesota) [2-36];
o cypress wetland (Florida) [2-37];
o brackish marsh (California) [2-38];
o high altitude meadows (California) [2-39];
o vegetated retention basins (Maryland) [2-40];
o southern freshwater marsh (Florida) [2-41],
Upland Retention, and Treatment o.f Stormwater
During the past 10 to 15 years, one of the main focuses of stormwater
management has been on methods of retarding and attenuating stormwater
22
-------
runoff in urban settings and other upland areas. The purpose has been
to provide acceptable levels of drainage relief and flood control. A
number of secondary functions are also served, including [2-42]:
o ground-water recharge;
o recreation and open space;
o surface water pollutant reduction;
o erosion control.
Three categories of practices which utilize the upland landscape for
surface runoff control can be identified:
(1) Detention/retention storage basins;
(2) Natural overland flow;
(3) Vegetated/grassed waterways.
o Detention/Retention Storage Basins
The use of landscaped basins for the detention or retention of surface
runoff has become a popular stormwater management technique throughout
the U.S. during the past 10 years.. Such facilities may take, the form of
either onsite or offsite impoundments where runoff is collected for (a)-
controlled downstream release (detention), or (b) containment, .and
infiltration (retention)j or a combination thereof. The design of such
facilities will vary depending upon the land costs, space availability,
physical and aesthetic characteristics of the area, topography, climate
and other local factors [2-42]. Whether or not the detention/retention
facility is to serve multipurpose uses, such as runoff
treatment/disposal and recreation, is a factor that may dictate size,
shape, depth and landscaping.
Detention/retention storage basins may provide for surface runoff
pollution control in a variety of ways [2-43]:
(1) Infiltration and entrapment of pollutants in the soil;
(2) Flow detention and velocity reduction which minimizes
erosive forces in downstream areas;
(3) .Delay and modulation of runoff pulses and consequent
shock loading of pollutants to receiving waters;
(4) On-site storage reduces flood-related surface water flows
across urban street surfaces where large quantities of
pollutants may be picked up and transported by runoff;
(5) Reduction of stormwater pollutant loadings, through the
settling of particulate matter and biological oxidation
of organic materials in ponding areas.
23
-------
Vegetatio.n at detention/retention facilities, primarily, is planted for
aesthetic reasons; however, other specific purposes might include
[2-42]:
o recreational needs (i.e., turfed ball fields);
o improved infiltration;
o erosion control; .
o barriers to auto and pedestrian access.
The planned use of vegetation for uptake or reduction of surface runoff
pollutants in these facilities has gained littnT attention to date.
o Natural Overland Flow
The technique of causing surface runoff to follow natural overland sheet
flow routes has become a preferred method of handling residential storm
drainage when practicable [2-34], The recommended practice is to direct
the runoff flow over and through turf, or other flow retardants such as
ground cover or forest litter. The longest overland flow distances
possible are desired.
Stormwater treatment functions served by natural overland flow are
similar to those achieved through detention/retention storage. In
particular this practice provides for:
o velocity and scour control;
o flow detention and lengthening of the time of concentration;
o retention and deposition of pollutants;
o some infiltration of Stormwater.
The main application of overland flow has been in the planning and
design of newly developing residential areas, particularly where
emphasis on maintenance of natural surroundings has a high priority.
Examples can be found throughout the IUS. Foremost, perhaps, is the
Wo.o.dlan.ds. Development in Houston, Texas, where overland flow of surface
runoff constitutes one of a number of natural drainage techniques aimed
at minimizing the hydrologic and water quality impacts associated with
urbanization [2-44], In this instance, maintenance of natural terrain
and ground cover were important criteria. In other cases, preliminary
site grading and artificial landscaping is done in order to establish an
overland flow drainage system.
The idea, of treating large volumes of collected surface runoff by
overland flow is currently under investigation in Utah. Under the
National Urban Runoff Program, an overland flow treatment strategy has
been devised, which will involve spreading surface runoff over a pasture
area [2-45].' This is intended to test the effectiveness of a natural
grassland in removing Stormwater pollutants. The system design will
rely largely on concepts borrowed from overland flow practices for
sewage treatment.
24
-------
o Grassed Waterways
Grassed or vegetated waterways have been used for many years in
connection with agricultural operations. Their primary purpose is to
convey surface runoff from a field, diversion or terrace with minimal
soil loss and flooding. The stabilization provides erosion control in
the channel by reducing the velocity of water near the bed [2-46, 2-47].
Additionally, the decrease in water velocity allows for greater
infiltration of surface water and increased deposition of sediment. The
potential use of grassed waterways for removal of other stormwater
pollutants has recently come under investigation [2-48, 2-49].
Important considerations and constraints regarding the use of grassed
waterways are:
o velocity and capacity of the water channel;
o large land area requirements;
o soil types;
o ground-water conditions;
o vegetative tolerance to drought and inundation.
25
-------
REFERENCES
2-1. Cowardin, L.M., V. Carter, F.C. Golet and E.T. LaRoe.
Classification of Wetlands and Oeepwater Habitats of the United
States. Prepared for U.S. Fish and Wildlife Service, Publication
FWS/OBS-79/31, December, 1979.
2-2. Tchobanoglous, G. and G. L. Gulp. Wetland Systems for Wastewater
Treatment: An Engineering Assessment. In: Aquaculture Systems
for Wastewater Treatment - An Engineering Assessment, S.C. Reed
and R.K. Bastian (eds). EPA-430/9-80-007, 1980.
2-3. Good, R.E., D.F. Whigham and R.L. Simpson (eds). Freshwater
Wetlands: Ecological Processes and Management Potential.
Academic Press, New York, N.Y., 1978.
2-4. Tpurbier, J. and R.W. Pierson, Jr. (eds). Biological Control of
Water Pollution. University of Pennsylvania Press, Philadelphia,
Pa., 1976.
2-5. Sutherland,. J.C. Investigation of Tertiary Treatment of
Municipal Wastewater Stabilization Pond Effluent Using River
Wetlands in Michigan. National Science Foundation Report
NSF/RA-770222, 1977.
2-6. Crites, R.W. Economics of Aquatic Treatment Systems, Paper
presented at the Aquaculture Systems for Wastewater Treatment
Seminar,. University of Cal-ifornia, Davis, Ca;, September 1979.
2-7. Yontka, D. and 0. Lowry. Feasibility Study of Wetland Disposal
of Wastewater Treatment Plant Effluent, Final Report.
Commonwealth of Massachusetts Water Resources Commission,
Research Project 78-04, 1979.
2-8. HartTand-Rowe,, R.C*B. and P.B. Wright. Swamplands for Sewage
Effluents: Final Report. Environmental-Social Committee Northern
Pipelines; Report No. 74-4. Information Canada Cat. No R72-13174,
#QS-1553-000-E-A1, Canada, May, 1974.
2-9. Fritz, W.R. and S.C. Helle. Cypress Wetlands for Tertiary
Treatment* Boyle Engineering Corporation, Orlando, Fla., March,
1979.
2-10. Fritz, W.R. and S.C. Helle. Cypress Wetland: A Natural Tertiary
Treatment Alternative. Water and Sewage Works, April, 1979.
26
-------
2-11. Mitsch, W.J., H.T. Odum and K.C. Eivel. Ecological Engineering
Through the Disposal of Wastewater into Cypress Wetlands in
Florida. Paper presented at the National Conference on
Environmental Engineering Research, Development and Design.
University of Washington, Seattle, Wa., 1976.
2-12. Kadlec, R.H. and D.L. Tilton. Waste Water Treatment Via Wetland
Irrigation: Nutrient Dynamics. In: Environmental Quality
through Wetlands Utilization. Proceedings from a Symposium
Sponsored by the Coordinating Council on the Restoration of the
Kissimmee River Valley and Taylor Creek-Nubbin Slough Basin,
Tallahassee, Fla., February 28-March 2, 1978.
2-13. Tilton, D.L. and R.H. Kadlec. The Utilization of a Freshwater
Wetland for Nutrient Removal from Secondarily Treated Wastewater
Effluent. Jour. Environ. Qua!. 8(3):328, 1979.
2-14. Fetter, C.W. Jr., W.E. Sloey and F.L. Spangler. Use of a Natural
Marsh for Waste Water Polishing. Jour. Water Poll. Control Fed.
50(2):290, 1978.
2^15. Spangler, F.L., W.E. Sloey and C.W. Fetter. Experimental Use of
Emergent Vegetation for the Biological Treatment of Municipal
Wastewater in Wisconsin. In: Biological Control of Water
Pollution, J. Tourbier andTTTW. Pierson, Jr. (eds). University
of Pennsylvania Press, Philadelphia, Pa., 1976.
2-16. Spangler, F.L., W.E. Sloey and C.W. Fetter. Wastewater Treatment
by Natural and Artificial Marshes. EPA-600/2-76-207, 1976.
2-17. Whigham, D.F. and R.L. Simpson. The Potential Use of Freshwater
Tidal Marshes in the Management of Water Quality in the Delaware
River. In: Biological Control of Water Pollution, J. Tourbier
and R.W. Pierson, Jr. (eds). University of Pennsylvania Press,
Philadelphia, Pa., 1976.
2-18. Grant, R.R., Jr. and R. Patrick. Tinicum Marsh as a Water
Purifier. Hearings of Committee on Merchant Marine Fisheries,
November 5, 1971, (92-17) pg. 173-191, 1971.
2-19. Mudroch, A. and J.A. Capobianco. Effects of Treated Effluent on
a Natural Marsh. Jour. Water Poll. Control Fed. 51(9), 1979.
2-20. Boyt, F.L., S.E. Bayley and J. Zoltek, Jr. Removal of Nutrients
from Treated Municipal Wastewater by Wetland Vegetation. Jour.
Water Poll. Control Fed. 49(5):789, 1977.
2-21. Zoltek, J., Jr., S.E. Bayley et al. Removal of Nutrients from
Treated Municipal Wastewater by Freshwater Marshes. Progress
Report to City of Clermont, Fla., September, 1978.
27
-------
2-22. Steward, K.K. and W.H. Ornes. Assessing a Marsh Environment for
Wastewater Renovation. Jour. Water Poll. Control Fed. 47(7):
1880, 1975. , . . ,
2-23. Seidel , K. Macrophytes and Water Purification. In: Biological
Control of Water Pollution, J. Tourbier and R.W. Pierson, Jr.
.(eds). University of Pennslyvania Press, Philadelphia, Pa.,
19.76. .
2-24. DeJong, J. The Purification of Wastewater with the Aid of Rush
or Reed Ponds. _In_: Biological Control of Water Pollution, J.
Tourbier and R.W. Pierson, Jr. (eds). University of Pennsylvania
Press, Philadelphia, Pa.,. 1976.
2-25. Sma.ll , M.M.
Wetlands and
and C.J. Richardson
Mi., 1976.
Marsh/Pond Sewage Treatment Plants. In: Freshwater
i Sewage Effluent Disposal, D. L. Til ton, R.H. Kadlec
rardson (eds). University of Michigan, Ann Arbor,
2-26.. Demgen, F.C. Wetlands Creation for Habitat and Treatment - At
Mt. View Sanitary District, California. Paper presented at the
Aq.uaculture Systems for Wastewater Treatment Seminar, University
of California, Davis, Ca., September, 1979.
2-27. Williams, T.C. and J.C. Sutherland. Engineering, Energy, and
Effectiveness Features of Michigan Wetland Tertiary Wastewater
Treatment Systems. Paper presented at the Aquaculture Systems
for Wastewater Treatment Seminar, University of California,
Davis, Ca., September, 1979.
2-28. Stonlick, H.T. Treatment of Secondary Effluent Using a Peat Bed.
In: Freshwater Wetlands and Sewage Effluent Disposal, D.L.
Til-ton, R.H. Kadlec and C.J. Richardson (eds). University of
Michigan, Ann Arbor, Mi., 1976.
2-29. Farnham, R.S. and D.H. Boelter. Minnesota's Peat Resources:
Their Characteristics and Use in Sewage Treatment, Agriculture,
and. Energy. In: Freshwater Wetlands and Sewage Effluent
Disposal, D.L. Tilton, R.H. Kadlec and C.J. Richardson (eds).
University of Michigan, Ann Arbor, Mi., 1976.
2-30. Dinges, R.A. Proposed Integrated Biological Wastewater Treatment
System. In: Biological Control of Water Pollution, J. Tourbier
and R.W.~P~ierson, Jr. (eds). University of Pennsylvania Press,
Philadelphia, Pa., 1976.
2-31. Wolverton, B.C., R.M. Barlow and R.C. McDonald. Application of
Vascular Aquatic Plants for Pollution Removal, Energy, and Food
Production in a Biological System. In: Biological Control of
Water Pollution* J. Tourbier and R.W. Pierson, Jr. (eds).
University of Pennsylvania Press, Philadelphia, Pa., 1976.
28
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2-32. Reed, S.C. and R.K. Bastian. Aquaculture Systems for Wastawater
Treatment: An Engineering Assessment. EPA 430/9-80-007, 1980.
2-33. U.S. Environmental Protection Agency. Land Treatment of
Municipal Wastewater Effluents - Design Factors I. EPA
Technology Transfer Seminar Publication, January 1976.
2-34. Residential Storm Water Management. Published jointly by the
Urban Land Institute, the American Society of Civil Engineers,
and the National Association of Home Builders. 1975.
2-35. Jones, D.E. Where Is Urban Hydrology Practice Today? Jour. Hyd.
Div. ASCE, Vol. 97, No. HY2, February, 1971.
2-36. Hickok, E.E., M.C. Hannaman and N.C. Wenck. Urban Runoff
Treatment Methods: Volume I - Non-Structural Wetland Treatment.
EPA-600/2-77-217, Cincinnati, Ohio, 1977.
2-37. East Central Florida Regional Planning Council. Orlando
Metropolitan Areawide Water Quality Management Plan 208, Vol. 3.
June, 1978. .
2-38. Association of Bay Area Governments. Treatment of Stormwa.ter
Runoff by a Marsh/Flood Basin. Interim Report to U.S. EPA,
August 1979.
2-39. Morris, F.A., M.K. Morris, T.S. Michaud and L.R. Williams.
Meadow!and Natural Treatment Processes in the Lake Tahoe Basin:
A Field Investigation. U.S. EPA, Environmental Monitoring
Systems Laboratory, Las Vegas, Nev., 1980.
2-40. McCuen, R.H. On-Site Control of Nonpoint Source Pollution.
Proceedings: Stormwater Management Model (SWMM) Users Group
Meeting, November 13-14, 1978. EPA-600/9-79-003, November, 1978.
2-41. Motchkaritz, R. Drainage System Design, and Analysis - Tampa
Palms, Hillsborough County, Florida, Application for Development
Approval. August 1979.
2-42. Poertner, H.G. Practices in Detention of Urban Storm Water
Runoff. APWA Special Report No. 43, 1974.
2-43. Lynard, W.G., E.J. Finnemore, J.A. Loop and R.M. Finn. Urban
Stormwater Management and Technology: Case Histories.
EPA-600/8-80-035, August, 1980.
2-44. Characklis, W.G., F.J. Gaudet, F.L. Roe and P.B. Bedient.
Maximum Utilization of Water Resources in a Planned Community.
EPA-600/2-79-050b,"July 1979.
2-45. Salt Lake County Division of Water Quality and Water Pollution
Control. Salt Lake County Urban Runoff Program. November, 1979.
29
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2-46. U.S. Department of Agriculture, Conservation Services. Handbook
of Channel'Design for Soil and Water Conservation..; SCS-TP-61,
'Washington', D.C., 1947, revised June,, 1954.
2-47. Kouwen, N., R.M. Li and D.B. Simons. Stability Criteria for
Vegetated'Waterways. Paper presented at the International
Symposium on Urban Storm Runoff, University of Kentucky, July,
1980.'
2-48. Asmussen, I.E., A.W. White, Jr., E.W. Hauser and J.M. Sheridan.
Reduction of 2,4-D Load in Surface Runoff Down a Grassed
Waterway. Jour. Environ. Qua!. 6(2):159, 1977.
2-49. Wilson, L.B; Sediment Removal from Flood Water by Grass
Filtration. Trans. ASAE, pg. 35-37, 1967.
30
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SECTION 3
WASTEWATER CHARACTERISTICS
There is no known limitation on the quality of municipal wastewater or
urban runoff that may be successfully treated by vegetative practices.
In practice, treated wastewater and runoff representative of typical
conditions have been applied to vegetative systems. It is likely that
"typical" waters, particularly those at the cleaner end of the range,
would predominate in near-future applications. This section identifies
basic characteristics of municipal wastewater and runoff, permitting a
potential user of a vegetative treatment scheme to compare the quality
of the proposed waste with "typical" and with case study waters
discussed in subsequent sections.
MUNICIPAL WASTEWATER CHARACTERISTICS
Raw Sewage
Untreated municipal wastewater has not been consciously applied directly
to marshes or other vegetative systems, nor have studies of the effect
of these systems upon raw sewage quality been uncovered. However, the
quality of treated municipal effluents depends upon the nature of the
raw sewage and the selection of unit treatment processes to remove
specific pollutants from the sewage. Typical pollutant concentration
ranges for raw sewage are presented in Table 3.
Treated Wastewater
The most commonly encountered wastewater treatment stages are (a)
primary, where sedimentation removes the bulk of settleable solids and a
portion of organic matter, and, (b) secondary, where biological
oxidation produces significant reduction in the balance of the organic
matter. Variations of the two basic treatment stages include chemical
coagulation, extended aeration, filtration, algal polishing, chemical
destruction (e.g., chlorination) and air stripping. These variations
can be part of the basic processes of sedimentation and oxidation or can
be added to a process train. Each variation or additional unit process
is generally targeted at a specific group of wastewater constituents
such as suspended participates, colloids, organic matter, nutrients,
toxics, pathogens and dissolved salts. Most additional unit treatment
processes are .designed based on an influent of typical primary or
secondary effluent (Table 4). As a starting assumption, primary or
secondary effluent would be the most common wastewater supplied to
31
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TABLE 3. COMPOSITION OF RAW MUNICIPAL WASTEWATERS
..... . .. ..Constituent
Solids; total
Dissolved solids, total
Mineral
Volatile'
Suspended solids, total
Mineral
Volatile1
Settleable solids, (ml /liter)
Sett! eat! e solids, total
Mineral1
Volatile
Biochemical oxygen demand,
(BOD5) 20°C
Ultimate carbonaceous
Ul titrate -nitrogenous
Total oxygen demand (TOD)
Chemical- oxygen demand (COD)
Total organic carbon (TOC)
Nitrogen,- total as: N
Organic
Ammon'ia
Nitrites'--
Nitrates
Phosphorus1;- 'total- as P
Organic'
InorgaHic
Chlorides added
Alkalinity added,' as CaC07
Grease .
Raw wastewater
Metcalf & Eddy,; Inc.3. .
350-1,200
250-850
145-525
105-325
100-350
30-75 .
70-275
5-20
--
__
__
100-300
__
_-
250-1,000
100-300
20-85
8-35
12-50
0
0
6-20
2-5
4-15
30-100
50-200
50-150
range, mg/1
U.S. EPAb
700-1 ,000
400-700
250-450
150-250
180-300
40-70
140-230
~_
150-180
40-50
110-130
160-280
240-420
80-140
400-500
550-700
200-250
40-50
15-20
25-30
0
0
10-15
3-4
7-11
50-60
100-125
90-110
a. Source: reference 3-1.
b. Source:- reference 3-2.
32
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TABLE 4.
COMPOSITION OF TREATED MUNICIPAL WASTEWATERS
Primary effluents, mg/1
Constituent
BOD5
COD
Suspended solids
Nitrogen, total as N
Ammonia, as N
Phosphorus, total as P
Total coliforms,
MPN/100 ml
Average3
136
330
80
35
--
7.5
2xl06
Range3
70-200
165-500
40-120
5xl06-5xl08
Rangeb
68-243
--
27-100
16-45
9-27
1.2-9.8
Secondary effluents , mg/1
Average3
25
55
15
30
--
5.0
IxlO3
Range3 Range0
15-45 4.4-241
25-80
10-30 19-129
23-48
5-29
1.2-9.1
Ixl02-lxl04
a. Source: reference 3-6.
b. Derived from 1978 end-of-year-average self monitoring reports for San Francisco (3 plants),
Pittsburg, East Contra Costa, San Mateo, Benicia, Pacifica, Estero and Sausalito, California.
Unpublished NPDES data.
c. Derived from 1978 end-of-year-average self monitoring reports for Central Contra Costa, East
Bay Municipal Utilities, San Jose, Redwood City, San Carlos-Belmont, Hayward, North San
Mateo Co., Oro Loma, Novato-Ignacio, Petaluma, Sonoma Valley and Mountain View, California.
Includes activated sludge, trickling filters and lagoons. Unpublished NPDES data.
-------
vegetative treatment sy stems t- Additional treatment processes, added
before discharge-'of effluent to a marsh or wetland, would usually reduce
concentrations of certain wastewater constituents, such as toxic metals,
or .'change their" chemical nature, such as converting ammonium to nitrate.
Trace:ETemertts ;i h Munici pa1 Hastewaters
Of'particular concern in the planning of a vegetative system for the
treatment of municipal wastewater effluents is the presence of trace
elements, often referred to collectively as trace metals. These
elements include copper, lead, silver, cadmium, chromium, arsenic,
mercury and zinc. All these elements are of interest because of their
potential, when present in sufficient quantities, for toxicity to living
organisms, including those responsible for biological activity in a
wastewater treatment process. The presence of trace elements in
municipal wastewater can vary by orders of magnitude, chiefly depending
upon the addition of industrial wastes to the municipal sewage system.
Trace elements can be present in natural water supplies, added from
materials.-usedin water distribution systems, or from purely domestic
wastes. Table 5 presents reported trace elements in raw municipal
wastewaters. Table 6 lists trace elements in treated wastewaters.
Si nee-the sources of the data are generally not'the same for raw and
treated wastewaters, the values presented are not precisely indicative
of the:-effectiveness of levels of treatment and should only be used as
typical concentrations iri different types of effluent.
Wastewater: Particle-Sizes
To the' relative extent that a vegetative treatment system would employ
sedimentation, filtration, adsorption and absorption as pollutant
removal mechanisms-i the distribution of pollutants in a particular waste
would affect the-potential efficiency of the treatment system. Figure 2
anfl Tabler 7 present size distributions of wastewater particles. It
shbuld'be no ted- that- with increasing treatment of wastewater from raw
sewage to .secondary: effluent-, there are greater reductions in colloidal
and settle able material than: in soluble or supra-colloidal matter.
Thus, with; increasing effluent quality discharged to a vegetative
treatment system, the principal pollutant removal mechanisms in the
vegetative- system should shift from sedimentation or filtration to
adsorption and absorption, and the system may have to.be selected
accordingly. ::
Flow
The size of the wastewater collection system impacts no other effluent
characteristic as much as it does the hourly variations in flow.
Extreme hourly variations in single domestic service flows only
gradually become attenuated with increasing numbers of connections.
Small city wastewater flows fluctuate significantly more than those from
larger cities. As shown in Figure 3, the 24-hour flow variations from a
population of 5,000 could range from 0.4 to 2.5 times the average daily
34
-------
TABLE 5. TRACE ELEMENTS IN RAW MUNICIPAL WASTEWATER (mg/1)
CO
(J1
Northeast3
Metal
Arsenic
Cadmium
Chromium
Copper
Iron
Lead
Mercury
Nickel
Silver
Zinc
Median
<0.02
<0.05
0.10
0.90
<0.20
0.0013
<0.10
<0.05
0.18
25-90%
.
<0.02
<0.05
0.05
0.50
Range
-<02
-0.30
-0.40-
-2. '50
<0.20
b. January-June 1973. Allegheny Co.. Pennsylvania (3-4)
c. 1973 yearly average, Muncle, Indiana (3-4)
-------
TABLE 6. TRACE ELEMENTS IN MUNICIPAL EFFLUENTS
Primary effluents, mg/l
Element
Arsenic
Cadmium
Chromium
Copper
Iron
Lead
Manganese
Mercury
Nickel
co
CTi Silver
Zinc
Untreated
wastewatera, mg/l
0.003
0.004-0.14
0.32 -0.700
0.02-3.36
0.9-3.54
0.05-1.27
0.11-0.14
0.002-0.044
0.002-0.105
0.030-8.31
National3
0.002
0*004-0.023
< 0.001-0. 30
0.024-0.13
0.41-0.83
0.016-0.11
0.032-0.16
0.009-0.035
0,063-0.20
0.015-0.75
Northern
Average
D.013
0.03
0.04
0.085
. ^-
0.1
.
: 0.0017
0.15
0.02
0.31
California11
Range
0.004-0.02
0.003-0.1
< 0.005-0. 183
0,04-0.125
0.32-0.2
--
0.0002-0.004
0.01-0.4
0.005-0.05
0.06-1.05
National'
0.005-0.01
0.0"02-<0.32
< 0.010-0.17
0.05-0.22
0.04-3.89
0.0005-«0.20
0.021-0.38
0.0105-0.0015
< 0.10-0. 149
O.W7-0.35
Secondary effluents, mg/l
Northern
-i Average
0.0007
0.006
0.01
0.056
'. --
0.038
. ':
0.0009
0.06
0.19
0.15
California^
Range
0.0005-0.019
0.0005-0.01
0.0005-0:03
0.01-0.12
--
0.01-0.06
--
0-Q.002
0:03-0.2
O.C02-0.034
< 0.05-0. 32
a. Source: reference 3-7.
b. Derived from 1978 end-of-year self-monitoring report averages for Benlcia, Pad flea. Estero, Ptttsburg, San Mateo,
San Francisco Southeast. San Francisco Northeast and SausalHo-Marln City, California. Unpublished NPDES data.
c. Derived from 1978 end-or-year self-monitoring report averages for Hayward. Central Contra Costa, East Bay
Municipal Utility, Novato-lgnaclo, Petaluma, Sonoma Valley, Mountain View, North San Mateo County,
Oro Loma and San Jose, California. Unpublished NPDES.data.
-------
Dissolved
Classification of particle
Colloidal
Size of particle, microns
IO-5 IO-4 10-3
Suspended or nonf ilterable--
IO-2
10-'
10
100
10-8 IO-7 IO-«
Size of particle , millimeters
10-S
10-4
10-3
10-2
Removable by coogulption
Settleable-
Figure 2. Classification of particles found in water.3
a. Source: reference 3-1.
TABLE 7. SIZE DISTRIBUTION OF WASTEWATER PARTICLES3
Fraction
Soluble
Colloidal
Supra-
Colloidal
Settleable
Size
range,
microns
< 0.001
0.001-1
1-100
MOO.
Raw
Total
solids
mg/1
351
31
57
74
wastewater
Volatile
, matter,
mg/1
116
23
43
59
'Secondary
Total
solids,
mg/1
312
8
28
0
effluent
Volatile
matter,
mg/1
62
6
24
0
a. Source: reference 3-8.
37
-------
.1;
0.01
i r i IN
0.5 1.0 15 2.0 3.0
4.04.5
0.05 O.I
Average daily discharge, m'/sec.
Figure 3. Variations in municipal wastewater flows.
Source: reference 3-1.
38 .
-------
flow while for a population of one-hal f million, the range could be 0.7
to 1.5 times the average daily flow. Assuming minimum attenuation of
the flow through the sewage treatment facility, these numbers represent
typical variations in effluent loading upon a subsequent vegetative
treatment system. However, as subsequent sections will point out,
compared to stormwater runoff flows, treatment plant effluents are
considerably less variable.
STORMWATER RUNOFF
Urban Runoff
Urban runoff is generated by rainfall upon land areas developed for
residential, commercial or industrial uses and includes roadways. Urban
runoff is generally considered to be surface runoff discharged by
overland flow or through storm sewers. In a number of older cities,
particularly in the eastern United States, sanitary sewers were designed
to carry urban stormwater. The flow of these combined sewers, in excess
of their carrying capacity or ultimate treatment capacity is combined
sewer overflow (CSO).
Table 8 presents reported water quality from two studies on urban runoff
and CSO's. Combined sewer overflows carry more organic wastes,
nutrients and bacteria than urban runoff, due to the sanitary sewage
component. However, urban runoff contains significantly higher
percentages of inert suspended solids.
The quality of urban runoff water has been shown to be dependent upon
the land uses in the contributing watershed. Table 9 provides a direct
comparison of runoff qualities from industrial, commercial and
residential neighborhoods in the Chicago metropolitan area. In general,
commercial neighborhoods produce the poorest quality of urban runoff,
but not by orders of magnitude. Also, light industrial neighborhoods
generated runoff quality higher than for the other categories. This
could be an unexpected finding unless it is kept in mind that light
industrial areas, with landscaped grounds, warehouses and offices, more
closely resemble low-density residential neighborhoods than heavy
industrial areas with large factories, rail yards, shipments of raw
materials and finished products, and possible direct pollutant
emissions.
Table 10 presents urban runoff sampling results from the San Francisco
Bay Area. In the eastern and central United States, where previously
reported studies were conducted, storm runoff occurs during the summer
and is quite different in character from gradual winter snowmelt. In
the western states, summer is characterized by extended dry periods with
most rainfall occurring during the period Navember to April. However,
the results presented in Table 10, although collected during a period of
unusally infrequent rainfall, are comparable to the Chicago data.
39
-------
TABLE 8. ; .URBAN STORMWATER AND'CSO QUALITY
Pollutant
BOO,
3
COD'
Suspended solids
Total solids
Organic nltrogen-N ,
flinnonlirai nltrogen-N
Total nltrogen-N
Phosphate-P
Total phosphorus-P
pH (units)
Total collform (MPN/100 ml)
Fecal collform (HPN/100 ml)
Chloride
Oils
Phenols
Lead
Field*
Urban storrowater,
range
11-500
--
500-11.300
1.000-14,600 .
0.9-16
0.4-2.5
--
10-125
2xl03-l4xl05
200-25.000
10-110
0-0.2
0-1.9
Pollutant concentrations, mg/1
Kaiser Engineers'" . . .
Urban stormwaterv ' CSOa
CSO. range mean6 std. dev. mean* std. dev. ' '
100-500 27 25 108 36
205 118 2B4 110
100-1 .500 60S 616 372 275
300-2,000 -- --
3.5-30.1
1.1-11.5
2.3 1.4 9 6
1-62 - - - -
0.5 0.4 2.8 2.9
4.9-8.4 -- -- -
5xl04-30xl06 3xl05 -- 6x10
5xl04-llxl06
..
-- .- ..
a. Source: reference 3-9.
b. Source: reference 3-10.
c. 20 cities, storm sewers and unsewered areas, unspecified locations.
d. 25 cities, combined sewer areas, unspecified locations.
e. Geometric mean.
-------
TABLE 9. COMPARISON OF URBAN RUNOFF BY LAND USE3
Concentrations, mg/1
Constituent
80%
COD
Total suspended
solids
Volatile suspended
solids
KJeldahl nitrogen
as N
Ammonium nitrogen
as N
Nitrite and
Nitrate as N
Soluble Phosphorus
as P
pH (units)
Single family
mean range
17 2-80
104 34-308
513 23-6.470
54 2-532
1.7 0.4-8.0
0.5 0.1-2.3
1.4 0.1-6.8
0.14 0.01-0.65
6.4-8.4
Multi-family
mean range
16 6-41
117 44-270
797 25-3,484
68 9-302
2.1 1.3-7.4
0.5 0.1-2.2
1.1 0.2-3.0
0.23 0.04-0.69
- 6.5-8.5
Commercial
mean range
22 7-53
168 36-301
386 26-2.938
44 4-164
2.0 0.8-4.5
0.5 0.1-1.3
1.6 0.3-3.1
0.24 0.02-2.18
6.8-8.5
Light Industrial
mean range
14 6-38
78 46-157
302 8-3,222
36 3-362
1.4 0.5-3.6
0.4 0.1-1.3
1.2 0.1-3.9
0.19 0.01-1.48
6.6-8.7
Highway
mean range
14 2-29
128 12-319
266 in- 1,4 32
47 3-160
1.2 O.K3.7
0.4 0.1-0.9
1.1 0.4-3.4
0.07 0.02-0.13
6.5-8.2
a. Sampling of April-July 1977. Chicago Metropolitan Area (3-17).
-------
TABLE 10, SAN FRANCISCO BAY AREA URBAN RUNOFF MONITORING RESULTS
.GROUPED BY PREDOMINANT LAND USE3
Average pollutant concentrations, mg/1
Land use
Residential'
Alameda
Castro Valley
1971-1972
1972-1973
1976-1977
Glen Echo
Peralta
Richmond
Contra Costa
Pine Ck.
Rheem
San Ramon at
Walnut Creek
Walnut Creek
Napa
York Street
San Nateo
Brews ter
Colraa
Serramonte
Santa Clara
Calabazas
Guadalupe
Commercial
Santa Clara-San Jose
Industrial
Santa Clara (light)
Santa Clara (heavy)
San Mateo-8ay front .
Open
Contra Costa-San Ramon
Rudgear
Contra Costa-Little Pine
Marin-Sleepy Hollow
Santa Clara-Serryessa
t in
that use
70
60
»_
76
23
75
19
34(7)
90
100
21
81
38
33
100
100
100
80
94
100
80
73 .
Number of
samples
36
59
33
40
26
50
11
4
3
8
22
1
1
1
46
32
' 36
28
37
1
3
1
41
80
BOO
6.7
31.0
25 ;7
40.3
24.9
19.8
__
21.0
8.5
8.8
22.0
7.0
16.0
14.0
19.4
27.0
21.1
38.1
13.0
16.0
6.8
9.7
4.3
8.0
SS
904
945
339 ,
227
«.
115
^_
211
129
132
81
145
207
85
557
461
158
72
114
90
220
5200
87
1134
VSS
--
39
__
28
19
23
36
54
43
28
88
98
67
21
45
26
38
550
16
146
total N
2.0
3.7
-
..
2.7
3.2
^_
4.5
1.4
2.7
1.2
3.5
3.5
1.3
4.5
6.4
7.0
3.1
4.5
1.3
3.8
2.6
2.4
3.(
Total P Population
density,
*/acre
0.7
0.8
..
0.7
0.4
0.6
0.4
0.6
0.4
0.02
0.3
0.2
0.9
0.8
0.7
0.4
0.3
0.2
0.6
2.4
0.2
1.0
21.4
26.1
21.7
..
..
-.
11.4
14.0
14.0
.-
--
18.2
16.7
.-
--
-.
..
-
a. Monitoring of 8 counties during 1976-77 rainy season, 1-7 storms per site (3-12).
42
-------
Although there are differences in runoff quality based upon source, the
differences are not extreme. It is therefore possible to assume a
typical range of values for planning purposes although specific site
characterization should be performed before actual design of any urban
runoff treatment facilities. Unique local conditions may alter the mass
emission of one or several runoff components. For example, the
Association of Bay Area Governments found that in newly developing
areas, construction-related erosion caused 15 to 20 times as much soil
loss as background conditions, and in one watershed in Santa Clara
County, 72 percent of the sediment leaving the basin originated from 6
percent of the land area [3-19], Thus, the planner and designer must
not only identify the unique contributing factors in a watershed but
also should be aware that some factors, such as construction-related
erosion, may be transitory and gone, or increasing, within several
years.
Rural Runoff
The emphasis of this study is on urban runoff and wastewaters. However,
the techniques of vegetative treatment are certainly applicable to rural
or agricultural runoff. Table 11 presents typical values of
agricultural runoff as collected from several sources. Forested land
produces lower pollutant concentrations than urban runoff but as
agricultural activities increase through the categories of rangeland,
cropland and feedlots, the runoff quality significantly deteriorates in
terms of suspended solids and nutrients. It would appear that remedial
measures should be directed at solids control and reduction of
nutrients.
Trace Elements In Urban Runoff
Data on trace elements in urban runoff are sparse. Table 12 presents
concentrations of trace elements found in San Francisco Bay Area urban
runoff. The highest concentrations found were of lead, zinc and arsenic
and the lowest of silver, cadmium and mercury. However, these
concentrations do not reflect the toxicity of the individual elements to
specific organisms. Therefore, a program to remove toxic elements would
depend upon the element and the target organisms to be protected or
water quality standard to be achieved.
Table 13 contains the analysis of trace elements in stormwater solids
filtered from samples collected from storm sewers. The most common
element is iron at 28.4 g/kg followed by lead and zinc at 3.99 and 1.21
g/kg, respectively.
Hydrocarbons In Urban Runoff
Concern may arise about the hydrocarbon content of urban runoff. With
potential sources ranging from oil spills and crankcase drippings to
exhaust emissions and illegal dumping, urban runoff has the potential
for direct, significant contamination of receiving waters by
hydrocarbons.
43
-------
TABLE 1.1. AGRICULTURAL RUNOFF CHARACTERISTICS
Concentrations, mg/1
Land Use
Forested land*
Forested landb
Hilly, lightly
grazed parkland0
Rangeland , open
and MllyC
wooded, hillyc
Agricultural cropland3
Agricultural cropland
Irrigation tile drain-
age, western U.S.8
Cropland tile drainage9
Seepage from stacked
manure3
Feed lot runoff3
Data
type
range
avg.
. range
avg.
range
avg.b
range
avg.
range
avg.
range
range
range
range
range
B0%
'.-
2
1-5
5.1
3.1-7.4
5.3
5-5.9
7
13
3-35
10,300-13,800
1,000-11,000
Suspended
solids
34
20-51
1 ,290
488-2.075
600
228-1 ,010
580
222-924
--
762
5-6.100
1
- -.
Volatile
suspended
solids
7
3-13
133
55-164
88
26-138
59
46-77
_._>
99
1-883
_-
--
Total
nitrogen-N
0.3-1.8
0.5
0.2-0.6
1.6
0.19-3.5
4.9
1.3-8.1
3.0
2.3-3.4
9
2.9
0.1-12.9
2.1-19
10-25
1.800-2,350
920-2,100
Nitrate
nitrogen-N
0.1-1.3
0.2d
0.1-0.4
__
0.4
4,2
0.3-23.5
1.9-19
10-23
Total
phosphorus-p
0.01-0. It
2.4
1.0-3.3
0.77
0.27-1.9
0.35
<0.2-0.46
0.02-1.7
--
0.01-0.3
0.02-0.7
190-280
290-360
Soluble
phosphorus-P
0.04
0.01-0.06
-T
"
__
0.27
0.02-1.54
__
--
-.
a. Source: reference 3-7.
b. Source: reference 3-17.
c. Source: reference 3-11.
d; Nitrite plus nitrate nitrogen.
-------
TABLE 12. TRACE ELEMENTS IN URBAN RUNOFF3
Flow weighted nean concentrations, ng/1
land use Lead Cadmium Chroolua Silver Nickel Arsenic Hercury Copper Zinc
Residential 0.61 0.01 0.02 0.005 .0.09 0.21 0.01 0.15 0.58
Commercial 0.85
Industrial 1.3 -- . ~ --
Open and
agricultural 0.15 0.007 0.007
a. 1976-77 sampling of San Francisco Bay Area counties (3-12).
TABLE 13. TRACE ELEMENTS IN STORMWATER SOLIDS3
Metal concentrations, mg/kg
Lead
3,990
Chromium
58
Nickel
57
Copper
325
Zinc
1,210
Iron Manganese
28,400 398
a. Stormwater solids
-------
The $wo -basic classes of hydrocarbons present in petroleum oils are the
aliphatics and iJaroina tics. Aliphatic hydrocarbons have the carbon atoms
in\an opien:-chain structure and .are fatty in nature. Aromatic
hydrocarbons have the carbon -atoms arranged-'in a closed-ring structure,
of which ben-zene is 'th'e 'elementary form.
Upo'n: ent'ertn'g ani aqueous environment, the" chemical structure of the
hydrocarbon. rdetermines its: fate. Most hydrocarbons , are 'insoluble and
either adsorb ;to particles in. the water or float on the -water surface as
a film. . The low molecul ar weight hydrocarbons, bo:th aliphatic and
aromat.f'C'j .are --quite volatile and ^evaporate quickly. Often these
compounds' 'have' evaporated "almost completely before the -runoff-causing
storm event occurs.- The hydrocarbons adsorbed to particul-ate matter
settle 'to ';t he bottom where microbial degradation can occur. The highly
branched' al iphatics 'and- the remaining" aromatic hydrocarbons biodegrade
very ,slowl-y, if at all. ....
Tab-le 14 presents the limited data available on hydrocarbons in urban
runoff. . They generally .represent the low-volatility hydrocarbons that
rema'in' 'after rsoftie 'period 6f -exposure to the air. Most references
indicate -that automobile crankcase drippings are responsible for the
hydrocarbons
-------
TABLE 14. HYDROCARBONS IN URBAN RUNOFF
Average
suspended
Source solids, mg/1
Philadelphia, Pa.a 87
San Francisco Bay
Areafa
Residential
Comrerd a 1
Industrial
Seattle, Wa.c
Urban
Highway bridge
Urban freeway
Philadelphia, Pa. f
Hydrocarbon
type
Aliphatic
Aromatic
Total
Total oil
and grease
011 and greased
Aliphatic
n-parafflnS
011 and grease"
Aliphatic
n-paraffln
011 and grease11
Aromatic
Total petroleum
Average hydrocarbon concentrations, mg/1
Parti cul ate
2.28
1.01
3.29
..
..
__
. --.
--
--
--
1.25
4.28
Soluble
0.29
0.11
0.40
..
~-
..
..
--
..
0.06
0.25
Total
2.57
1.12
3.69
6
28
25
10
1.2
0.013
27
12
8.10
44
Range, mg/1
__
--
5-8.3
5-33
1.0-16
0.2-7.5
O.OW-0.35
0-95
6.0-24
0.025-0.25
10-60
.
a. 5 storms in 1974 (3-14).
b. Source: reference 3-11.
c. Source: reference 3-15.
d. Other Seattle studies referenced 1n 3-15.
e. n-paraffln « C13 3g except pristane C19 and phytanec
f. 3 storms In 1975 (3-16),
2Q
47
-------
TABLE .15. SIZE DISTRIBUTION OF URBAN STORMWATER PARTICULATES3
Southeast Michigan
3 urban watersheds runoff average
EPA
5. cities street solids average
size
range (^m)
<53
53-106
107-250
251-850
; >850
percent
by weight
81.7
7.0
4,1
4.3
2.8
size .
range (ym)
.<43
43-104
105-246
247-840
.>MO
percent
by weight
13.5
11.0
17.6
22.2
35.6
a. Source.: reference 3-18.
48
-------
urban runoff pollutant sources, others being lawns, roofs, driveways,
parking lots, inlets and catchbasins, parks and open areas. Thus,
studies that characterize street sweepings do not accurately reflect
true stormwater pollutant characteristics.
Urban Runoff Flow Characteristics
An important characteristic of urban runoff flow is its variability.
While a municipal wastewater treatment facility may discharge an
effluent that varies +_50 percent from average in a day, urban runoff
will occur as intense runoff during short periods, often separated by
very long dry periods. Table 16 lists the number of days per year that
precipitation exceeds 0.25 mm (0.01 in) in several major cities. It is
apparent that any vegetative treatment system for urban runoff must
tolerate extended dry periods between rainfall events. When rainfall
occurs during specific .seasons, the vegetative treatment system must
withstand drought (typically five months in the San Francisco Bay Area),
must include storage of water, or have an alternate source of water to
maintain vegetation.
In addition to accommodating significant variations in stormwater runoff
frequency, a vegetative treatment system will experience variable flow
during a storm event. Figure 4 shows typical hydrographs for developed
and undeveloped watersheds. Storm runoff into a treatment system will
rise to peak flow, then drop and taper.off slowly during any single
rainfall event. The effect of urban development, with its higher
proportion of impervious surfaces, upon a watershed, is to decrease the
time of concentration of flow and to increase total runoff from the
watershed. This produces significantly higher discharge peaks and
expands the range of hydraulic loading within which a treatment system
must function.
Dry weather storm sewer discharges may be an unexpected source of water
and pollutants. Although flows were not measured, recent dry weather
sanitary surveys in several South San Francisco Bay cities uncovered
significant storm sewer discharges [3-22]. Dry weather (no measurable
rainfall for 14 preceding days) log mean total coliform levels of 2.1 to
6.5xl04 MPN/100 ml approached wet weather levels of 2.5 to 12.6x104
MPN/100 ml for two major storm sewers. It is theorized that dry weather
flow sources are ground water, domestic lawn watering and car washing,
industrial dumping (particularly cooling waters), sanitary sewer
cross-connections, and sanitary sewer pump station bypasses.
49
-------
TABLE-:16. ' ANNUAL DISTRIBUTION OF RAINFALL EVENTS3
Month "''
January
February "
March
April
May
June
July '
August-
September' '
October^
November -
DecemHer'-
Total;;
.Numbe,
Oak Tan tf"
11
10
,' : 9
6
3
1
0
- : - T-
1
, , 4
7
10
, . 63
C;Pf/cjays,.
Denver
6
6
8
9
10
9
9
8
6
5
5
5. '
87 .
wjt,h.0.25 mm,.
Boston
12
n
12
12
12
11
9
10
; 9
9
n
10
128
rainfall
Mi ami '
6
5
6
6
10
15
16
16
17
15
8
6
127
or more
Chicago
10
10
12
13
12
10
9
8
8
7
10
10
120
Soiirtel" refeferjCe 3-23;
50
-------
500 -
400 -
= 300 -
0>
.200. H
5;
100-
25-Year Frequency--24 Hour Duration
Design Stora Hydrographs
270.6 Ac. drainage area
PEAK Q 425 cfs
at Hour 9.25
FUTURE CONDITIONS
(Post Development)
PEAK Q - 213 cfs
at Hour 11.0
EXISTING CONDITIONS
(Predevelopment)
'.?. 3; 4 5618 9 10 II 12 15 J4 15 16 17 18 19 20'
Time in hours
Figure 4. Typical small watershed hydrographs.
a. Source: reference 3-21.
51
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REFERENCES
3-1. Metcalf & Eddy, Inc. Wastewater Engineering. McGraw-Hill Book
Company, New York, N. Y., 1972.-
3-2. U.S. Environmental Protection Agency. Process Design
Manual-Wastewater Treatment Facilities for Sewered Small
Communities. EPA-625/1-77-009, October, 1977.
3-3. Mytelka, A.I. et al. Heavy Metals in Wastewater and Treatment
Plant Effluents. Jour. Water Poll. Control Fed. 45(9):1859, 1973.
3-4. Davis, J.A. and J. Jacknow. Heavy Metals in Wastewater in Three
Urban Areas. Jour. Water Poll. Control Fed. 47(9):2292, 1975.
3-5. Chen, K. Y. et al. Trace Metals in Wastewater Effluents. Jour.
Water Poll. Control Fed. 46(11):2663, 1974.
3-.6. Lager, J. A. and W. G. Smith. Urban Stormwate'r Management and
Technology: An Assessment. U.S. EPA, Environmental Research
Center, Cincinnati , Ohio, EPA-670/2-74-040, 1974.
3-7.'. U.S. Environmental Protection Agency. Process Design Manual for
Land Treatment of Municipal Wastewater Effluents .
EPA-625/1-77-008, October, 1977.
3-8. Rickert, D.A. and J.V.. Hunter. General Nature of Soluble and
Particulate Organics in Sewage and Secondary Effluent. Water
Research 5:421, 1971, as cited in EPA Process Design Manual for
Suspended Solids Removal. EPA 625/l-75^003a, January, 1975.
3-9. Field., R. Coping with Urban Runoff in the United States. Waste
Research 9:499, 1975.
3-10. U.S. Environmental Pro-tection Agency. Water Quality Assessment -
A Screening Method for Nondesignated 208 Areas. Environmental
Research Laboratory, Athens, EPA-60079-77-023, 1977.
3-11. RAMLIT Associates and Metcalf & Eddy, Inc. Areawide Pollution
Analysis with the Macroscopic Planning (ABMAC) Model. Association
of Bay Area Governments, Berkeley, Ca., 1980.
3-12. Metca.lf & Eddy, Inc. Surface Runoff Modeling. Association of
Bay Area Governments, Berkeley, Ca., 1978.
3--13. Wilbur', W.G. and J.V. Hunter. Distribution of Metals in Street
Sweepings., Stormwater Solids and Urban Aquatic Sediments. Jour.
Water Poll. Control Fed. 51(12):2815, 1979.
52
-------
3-14. Hunter, J.V. et al. Contribution of Urban Runoff to Hydrocarbon
Pollution. Jour. Water Poll. Control Fed. 51(8):2132, 1979.
3-15. Wakeham, S.G. A Characterization of the Sources of Petroleum
Hydrocarbons in Lake Washington. Jour. Water Poll. Control Fed.
49(7):1680, 1977.
3-16. MacKenzie, M.J. and J.V. Hunter. Sources and Fates of Aromatic
Compounds in Urban Stormwater Runoff. Environ. Sci. Techno 1.
13(2):199, 1979.
3-17. Polls, I. and R. Lanyon. Pollutant Concentrations from
Homogenous Land Uses. Jour. Envir.Eng. Div., ASCE, February,
1980.
3-18. Collins, P.G. and J.W. Ridgeway. Urban Storm Runoff Quality in
Southeast Michigan. Jour. Envir. Eng.Div., ASCE, February, 1980.
3-19. Jackson, L. Erosion Related Water Quality Problems. Water
Quality Technical Memorandum .No .. 55, Association of Bay Area
Governments, Berkeley, Ca., May, 1980.
3-20. Young, J. C. Removal of Grease and Oil by Biological Treatment
Processes. Jour. Water Poll. Control Fed. 51(8):2071, 1979.
3-21. Wanielista, M.P. Stormwater Managment - Quantity and Quality.
Ann Arbor Science Publishers, Inc., Ann Arbor, MI., 1978.
3-22. Jarvis, F.E. et al. Preliminary Sanitary Survey Report for the
South Bay Study Area. California Regional Water Quality Control
Board, San Francisco Bay Region, 1980.
3-23. Ruffner, J.A. Climates of the States. National Oceanic and
Atmospheric Administration, U.S. Weather Bureau, 1978.
53
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SECTION 4
PHYSICAL AND CHEMICAL POLLUTANT REMOVAL MECHANISMS IN WETLANDS
A description' of pollutant removal mechanisms that may operate in a
marsh excludes few aquatic processes that can be found in any natural
water body. All the mechanisms that are discussed in this section are
not important in every marsh. Indeed, some are mutually exclusive,
occur only, seasonally, or are of secondary importance at most sites.
However, most of these mechanisms are likely to occur to some degree in
the-majority of marshes.
This section describes pollutant removal processes that occur in natural
waters and- are likely to apply to marshes;. Many have not been
documented in marsh environments, largely due to the traditional neglect
marsh research has received as compared with studies of rivers, lakes
art'd oceans. Nevertheless, processes are discussed as long as they are
likely to occur in' some marshes to some degree. The types of marsh
environments that would tend to favor specific processes are described
in connection with each mechanism that does not have widespread
occurrence.
POLLUTANT MASS BALANCE
Ptfllutants may enter a marsh via surface runoff or point source
discharges. Other routes, e.g., through base flow, aerial fallout, and
mobilized; sol id waste deposits, are not addressed here although the same
treatment processes would be operative. For the purposes of this
section,. po'll utants are defined as alien substances, and native
sub's'tante's in excess of their natural concentrations. Pollutants can be
distinguished from the natural constituents of water by their source,
since they arise from man's activities.
Surface runoff pollutants entering a. marsh occur on the surface or in
the water column, either dissolved, emulsified, or in particulate form.
Likewise, surface water flowing from a marsh carries pollutants in the
s^ame ways. These substances are not necessarily the same as the inflow
ptf 11 utants. Many types of transformations occur in marshes and the
products may leave the marsh. Pollutants can be removed by a wetland
system through three main routes: loss to the atmosphere, incorporation
into sediments or biota, and degradation. Some products of pollutant
degradation may be inert or nontoxic, while others continue to pose
environmental hazards. For example, some readily oxidi zable organic
compounds aTe quickly converted to carbon dioxide and water. On the
other hand, some pesticides are very stable or yield stable degradation
54
-------
products which are also toxic to the environment. Regardless of the
nature of the products of pollutant transformations, they either flow
out of the marsh, volatilize, or remain in the marsh, fixed in biota or
sediments. A summary of the major pollutant removal mechanisms and the
contaminants affected is presented in Table 17.
POLLUTANT LOSS TO ATMOSPHERE
Generally, the atmosphere acts as a sink rather than a source of
pollutants to marshes. In some cases, however, aerial input may be an
important factor, such as for lead in auto exhaust [4-3], solids from
wind erosion of soil, and acid rain. Loss of pollutants to the
atmosphere occurs by evaporation [4-12] and by aerosol formation [4-10].
Evaporation is by far the more significant of the two mechanisms for
most marsh environments. The evaporation rate of a volatile substance
is controlled by air and water temperature, wind speed, subsurface
agitation, and the nature of any surface film that may be present. When
the wind speed at the water surface is less than about 3 m/s, the
volatilization rate is additively dependent on both wind speed and
subsurface agitation. Above that value, wind speed dominates [4-6],
The presence of a surface film can decrease the rate of volatilization
by acting as a barrier to volatile solutes in the water which are
insoluble in the film. Alternatively, the surface film can scavenge.
substances from the bulk water and concentrate them at the surface where
they, subsequently, are volatilized. Surface films occur in both
freshwater and marine environments. They are composed of a highly
variable array of compounds including fatty acids, esters, alcohols,
lipids, hydrocarbons and proteinaceous materials. Surface films can
contain dead fish, insects, and various living organisms and can be
richer than the subsurface water in phosphorus, nitrogen, carbon, most
heavy metals, chlorinated hydrocarbons and other materials [4-11, 4-12].
Concentrations of zinc, cadmium, lead and copper may reach 100 ppm in
surface films, promoting reactions that may not otherwise occur and
allowing ready entrance for the metals to the food web through surface
feeding fish, insects and other organisms.
Environmentally important pollutants for which volatilization may be a
significant fate include oils [4-19, 4-28, 4-48], chlorinated
hydrocarbons [4-10], 2,4-D esters [4-62], and elemental mercury [4-47],
The multitude of compounds making up petroleum oils vary greatly in
their volatility. The acutely toxic, low-boiling-point alkanes
evaporate quickly while the atmospheric loss of most large molecular
weight petroleum hydrocarbons is negligible.
Aerosol formation can be important in marshes only when a strong wind
blows over a long inundated fetch. The wind generates a foam from the
surface film which is enriched in pollutants [4-11], As the foam
bubbles burst, droplets are ejected into the air. Water and other
volatile substances quickly evaporate from the droplets, leaving the
aerosol residue.
55
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TABLE 17. PHYSICAL AND CHEMICAL POLLUTANT REMOVAL MECHANISMS IN WETLAND AND AQUATIC SYSTEMS
Pollutant affected
Mechanism
Physical
Evaporation
v V
o -o '
t- vi
* t> O "O
V O 06
4O irt O M
TJ
U C
"c §
O> B
L. B
o u
'X .
i/»
c
o
II 1
It I
:x
I
1
a.
«A
4-*
g
&
-
xs
? ,0 £
SS
« fl t.
T "* c *
«» p O l.
SU^- *S"S» Description
> X £
X Volatilization and aerosol ;
en
en
Sedimentation
Emulslftcatton
Adsorption
Filtration
X X X
x"
formation
Gravitational settling of
particles and adsorbed
pollutants
Suspension of chemicals
that are sparingly soluble
In water within an aqueous
environment
.Electrostatic attraction,
Van der Uaals force
Mechanical filtration of
particles through substrate,
roots or animal systems
Chemical
Chelatlon
Precipitation
Decomposition
Chemical adsorption
XX Formation of metal com-
plexes through Ugands
X X X Formation of or copreclplta-
. tton of Insoluble compounds
X XX X X X X Alteration of less stable
compounds by oxidation, re-
duction, hydrolysis or
photochemical reaction
XX X X X X Covalent bonding, hydrogen
bond formation, hydrophoblc
Interaction
a. Significant only for mercury.
b. Not significant for manganese and mercury.
-------
SEDIMENTATION
Sedimentation is one of the most important mechanisms by which
participate pollutants are removed from the water column. Particulate
matter may be considered a pollutant, either because it consists wholly
of pollutant material or because pollutants are adsorbed to the surface
of naturally occurring particles. The mechanisms by which substances
adhere to the surface of solids are dealt with later in this section.
The following describes the mechanics of particulate settling.
Sedimentation Theory
Three physical processes cause the movement of particles in water: (a)
Brownian motion^ (b) fluid shear, and (c) gravity [4-40], Brownian
motion, also called molecular diffusion or thermal agitation, is
important for extremely small particles with diameters less than about
lu [4-52]. Solids in this size range exhibit random vibratory motion
when suspended in water. This movement has little, effect on the removal
of solids from the water column since there is no net movement toward
the bottom. However, in the microzone at the sediment/water interface
this motion may bring solids close enough to larger particulates for
other forces to effect adsorption.
Gravity moves particles with a specific gravity greater than one
downward.while turbulence tends to cause resuspension. The competition
between these two forces determines the rate of settling for any
size/density class of suspended matter. Suspended solids in natural
waters and wastewaters range in diameter from O.OOSv to lOOp , but for
particles having diameters less than about 10p , the terminal settling
velocity is less than 0.01 cm/s [4-52]. Generally, the larger the
particle, the higher the settling velocity.
In natural waters, particulate matter usually occurs as a mineral in an
organic matrix [4-4, 4-5, 4-8, 4-24]. For example, the inorganic
portion may be clays, quartz particles or hydrous metal oxides while the
organic part is usually humic or fulvic acids. The organic/mineral
aggregates have a loosely articulated, globular structure, often with
void spaces [4-8]. The clay particles in fresh waters usually have
negative charges. Ions in the water surround negatively-charged
particles, forming an electrically neutral "double layer." Repulsion
between like charges prevents the particles from agglomerating into
larger, more readily settling solids. The degree and rate of
agglomeration of particles depends upon the frequency.of collisions
between particles in the water and the efficiency of the collisions.
Collision efficiency is a term for the likelihood that a collision will
result in the particles involved adhering to each other. Solutes in the
water dramatically affect collision efficiency. Solutes that adsorb to
the surface of particles can increase, decrease or reverse the surface
charge. In addition, dissolved ions that do not interact with the
colloidal particle can increase collision efficiency by compressing the
diffuse part of the electric double layer with counter ions, allowing
Van der Waals forces to cause agglomeration. An example.of this is the
57
-------
-enhanced settling of suspended matter in estuaries [4-8]. In fresh
water the collision efficiency is only 0.0001 to 0.000001, but in sea
.water it rises to 0.1 to 1.0. Thus, sediment-laden freshwater flows
entering an estuarine system should undergo enhanced solids deposition
as compared to an otherwise completely freshwater system [4-63],
As mentioned above, collision frequency is also important in the
sedimentation process. Quiescent bodies of. water, such as marshes and
other wetlands, often provide long detention times. Collision
.frequencies caused by Brownian motion for very small particles are very
low, but with long detention times there are sufficient contact
opportunities for significant agglomeration and settling of finely
divided solids.
'The nature of flow patterns through wetlands has been found to influence
deposition of suspended matter and overall pollutant removal
effectiveness. Sheet flow and meandering channels lead to large
effective flow areas and best deposition rates [4-64, 4-65, 4-66].
Studies with artificial wetlands at the Brookhaven National Laboratory
point to the importance of structural diversity, i.e., combining
marshes, meadows, ponds, etc. to promote circuitous flow and greater
.deposition of particulate matter [4-65],
Wetlands generally act as detention and regulating areas for
streamf-lows, with beneficial effects on downstream soil erosion. Within
the wetland itself, however, high flow rates associated with storm
episodes, seasonal runoff or regulated discharges may resuspend
previously deposited and decomposing organic matter and wash it out of
the wetland system [4-67, 4-68, 4-69],
'Sedimentation of Pollutants
Sedimentation of pollutant particulates or pollutants adhering to the
-.surface of particles can be the primary mechanism for removal of these
.substances from the water column. This process has been reported as
important for removal of particulate nitrogen [4-33], oils [4-17],
chlorinated hydrocarbons [4-5, 4-36], and metals, except for manganese
and nickel [4-8, 4-43]. The chemical character of marsh water and the
nature of the suspended solids determine the extent of pollutant
adsorption, onto the surface of the solids. Since the water chemistry
can vary widely among marshes, an :important mechanism at one location
may be secondary at another. Factors affecting adsorption of various
tSubstances to suspended solids and bottom sediments are addressed later
in this section.
EMULSIFICATION
Emulsions are finely dispersed colloidal mixtures of two or more
immiscible liquids. Emulsions are inherently unstable and the liquids
tend to coalesce unless an emulsifying agent is present to lower the
interfacial energy between the immiscible liquids. In natural systems,
58
-------
the most common occurrence is the presence of minute droplets of oil in
water [4-19, 4-48], The stabilizing agent is a soap, detergent, or
naturally occurring organic molecule, one end of which is polar and the
other nonpolar.
Emulsions are formed when highly turbulent conditions exist in the
presence of a suitable interfacial agent. This situation may arise at
waterfalls, cataracts, hydraulic jumps in a wastewater collection
system, or through the action of breaking waves. If stabilized, the
emulsion may persist into downstream water bodies such as marshes,
lakes, rivers or estuaries.
There are three principal mechanisms that destabilize emulsions in
natural waters [4-55]:
(1) A change in the chemical character of the water, i.e.,
temperature, pH, ionic strength or presence of certain
solutes, may reduce the ability of the agent to stabilize
the emulsion. Salinity increases, as would occur when
freshwater enters a salt marsh, aid the coalescence of
the emulsion colloids into larger drops.
(2) An increase in the concentration of oil decreases the
emulsion stability. This could occur when a marsh volume
is reduced by evaporation, thereby lowering the
water-to-oil ratio.
(3) Freezing and thawing of an emulsion usually causes it to
break-up [4-55].
Emulsion colloids are important to the fate of pollutants in wetlands
because, aside from containing toxic oils, they tend to accumulate
environmentally significant chemicals that are sparsely soluble in
water. This is important for pollutants such as mercury,
polychlorinated biphenyls (PCB's), and some pesticides [4-47],
ADSORPTION
The principal means of removal of dissolved pollutants by adsorption in
natural waters is adhesion to suspended solids or bottom sediments. The
solutes are bound to the solid phase by three main mechanisms [4-52,
4-37]:
(1) Electrostatic attraction or repulsion;
(2) Physical reaction (Van der Waals forces, hydrogen
bonding); and
(3) Chemical reaction.
Extensive contact between wastewater flows and wetland soils allows
these interactions to occur. The most effective results are attained in
59
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seepage wetlands where a large percentage of the flow passes through the
soil complex prior to entering ground waters or discharging from the
wetland [4-68]. In wetlands having poor soil permeability, such as
peatlands, shallow water depths and long residence times promote greater
contact with surface soils and increased pollutant removal efficiencies
[4-64].
Hickok and others have found the need to promote maximum interaction of
runoff and wastewaters with mineral soils for attainment of high levels
of phosphorus: removal in wetlands [4-70, 4-71], In addition to low
water depths, even distribution of water, such as sheet flow, enhances
soil-water contact over larger effective areas of the wetland [4-72],
Seepage wetlands function similarly to overland flow systems, with
nearly complete phosphorus removal through soil processes [4-68]. In
s.uch systems, unusually high runoff flows may pose problems by causing
overflows and bypassing of seepage routes [4-68].. Similarly, in
flow-through wetlands, high runoff events reduce opportunity for soil
contact and, as noted earlier, may be detrimental by washing sediments,
organic, matter and other constituents from the confines of the wetland.
A great number of substances adsorb to solids under conditions that may
be found in wetlands.. This phenomenon is well-documented in the
literature:
o organic compounds [4-4, 4-1.3];
o petroleum and other hydrocarbons [4-17, 4-19, 4-21, 4-37,
4.48,, 4-57];
o halogenated. hydrocarbons [4-1, 4-10, 4-25, 4-27, 4-47, 4-62];
o ammonium [4-44,. 4-45];
o phospharus [4.-14, 4-20, 4-30, 4-51];
o heavy metals [4-3, 4-8, 4-9, 4-15, 4-16, 4-24, 4-32, 4-34,
4-39; 4v43, 4-46,. 4-47, 4-50];
o bacteria and viruses [4-18, 4-47].
Petroleum?and;Other Organic Compounds
The. importance of sedimentation as a mechanism for removing adsorbed
petroleum from-the water column was di scus.sed earlier. Emulsified oils
can adsorb to particles but physical, agglomeration inhibits adsorption
[4-17]; Structural properties of organic compounds affect the capacity
for adsorption. The following general trends describe the tendency of
organic compounds, having different chemical structures, to adsorb onto
particulates in an aqueous environment [4-37]:
(!'). Increasing with molecular weight as a homologous series
is ascended, unless the molecule is so large as to be
filtered out by small carbon pores.
(2) Decreasing with the compound's polarity, and hence,
solubility;
60
-------
(3) Decreasing with the position of substitution of hydroxy
and amino groups on benzoic acids in the order: ortho,
para , and meta;
In addition, the character of the particle/oil/water system affects the
degree of sorption as follows [4-17]:
(1) Adsorption is greater with decreasing size of the sorbent
particles; up to the point where the small pore size
causes interference;
(2) Adsorption increases with increasing content of organic
matter in the particles;
(3) With very low organic compound concentrations in the
water, little adsorption occurs on inorganic particles
such as clays.
Most halogenated hydrocarbons and organic pesticides adsorb strongly to
particulate matter. In the case of the pesticide 2,4-D esters,
adsorption inhibits evaporative loss from the water which might
otherwise occur [4-62].
Ammonium
In salt water clay sediments, ammonium adsorption occurs predominantly
onto organic matter [4-44]. This adsorption is rapid and reversible.
When adsorption of ammonium to clays does occur, two mechanisms may
apply: (a) ion exchange, or (b) attachment to the interlayers of the
clay structure where replacement by other cations does not readily take
place.
Phosphorus
Phosphate in freshwater sediments is closely associated with iron and
aluminum by adsorption onto hydrous oxides of these two elements [4-51].
This adsorptive capacity is sensitive to both pH and redox potential
[4-30], Binding of phosphate decreases with increasing pH and
decreasing redox potential. These two factors can strongly influence
the migration of phosphate between sediments and the overlying water
[4-14, 4-30, 4-51]. Phosphate and iron are released in deeper sediments
when biological processes produce anoxic conditions. Dissolved
phosphate and ferrous iron diffuse toward the sediment/water interface
where the iron is oxidized and forms ferric complexes in the aerobic
microzone. These complexes adsorb the phosphate, trapping it in an
enriched layer at the top of the sediment. If the sediments become
completely anoxic, the ferric complexes break down, releasing the
phosphate.
61
-------
Heavy Metals
Many heavy metals readily adsorb to sediment and water column
participates in wetland environments [4-24], Ionic strength, pH,
temperature, redox potential and the presence of competing cations can
each affect-the degree of surface bonding. An exposition on the varied
.conditions promoting metal adsorption is beyond the scope of this
-section. The reader is referred to the authoritative book by Stumm and
Morgan [4-53] for a thorough treatment of the subject. To illustrate
the types of processes defining the fate of heavy metals in wetlands,
the following examples are presented:
(1) Cadmium is better adsorbed to suspended solids in low
ionic strength water than in high ionic strength water
under aerobic conditions [4-43]. In anoxic conditions,
cadmium exchanges with iron at the surface of ferrous
sulfide substrates [4-15].
(2) .Copper, unlike cadmium, is adsorbed more strongly in high
ionic strength water than in low ionic strength water
[4-43].
(3) Lead adsorbs to metal-organic complexes and to clay
minerals [4-46].
(4) Mercury readily adsorbs to solids but the route is
frequently from oil rather than from the water [4-47],
(5) Zinc adsorbs to colloidal hydrous oxides in salt water
environments [4-16].
Bacteria, and Viruses
Because of adhesive organic compounds or electrostatic charges on their
surfaces; microorganisms attach to particles in the water. The
adsorption of viruses .to suspended soil particles is a function of pH
and dissolved inorganic and organic materials [4-18]. Viruses can
remain for many months in the soil matrix and adsorption may even
prolong their survival [4-18]. Desorption may occur in response to
changing conditions, such as the presence of competing organic matter
for the adsorption sites. :
CHELATION
Chelation is the process by which metals are strongly bound in a complex
with anionic molecules, either inorganic or organic. The anionic part
of the complex is called the ligand. There are many sources of ligands
in wetland environments. Salt waters are rich in important inorganic
ligands, including chloride, sulfate and bicarbonate, which can form
62
-------
soluble complexes with trace metals. This chelation mechanism competes
with adsorption of the metals onto the surfaces of iron and manganese
hydrous oxides [4-43].
Organic ligands are also very common in natural waters. Partial
decomposition of organic matter produces a variety of low molecular
weight acids which chelate metals, including amino, butyric, citric,
formic, 2-keto-gl uconic , malic, oxalic, tartaric, and a variety of
lichen acids [4-24], In addition to forming complexes, these acids
lower the pH. This promotes the dissolution of metals from solids,
making them available for chelation. Large molecular weight organic
compounds that are found naturally also are important ligands.
Primarily, these are humic and fulvic acids [4-24, 4-46],
Many microorganisms actively excrete organic substances to chelate trace
metals [4-26, 4-34, 4-35, 4-54]. These are proteinaceo us compounds,
such as amino acids, which have electron-rich functional groups which
bind metal cations [4-56]. The ligands bind essential trace metals so
that they are available for uptake by the organism. Iron binding is a
good example of this process. In aerobic waters iron is in the ferric
state and quite insoluble, or in the ferrous state and slowly oxidizing
.to ferric [4-73]. By complexing ferric colloids, microbial exudates
keep the iron in the water column where it can be used as a nutrient.
Although iron is complexed more strongly, these same exudates readily
chelate copper. Copper is very toxic to microorganisms as a free ion
but when complexed, the toxicity disappears.
There are ligands in most wastewaters and stormwaters. The sources of
these ligands can be industrial, domestic, and agricultural chemicals.
A good example of this is iron fertilizer. Ethylenediaminetetraacetic
acid (EDTA) is present in fertilizer to permit uptake of the nutrient.by
plants [4-31]. Through runoff transport, EDTA and other ligands can
affect distribution of metals in wetlands and uptake by vegetation.
Chelation is important to the mobility of aluminum, cadmium, calcium,
chromium, copper, iron, lead, manganese, mercury, nickel and zinc. In
addition to dissolving inorganic phosphate compounds, a number of
organic acids may act 'as chelating agents, complexing calcium, iron,
manganese, and aluminum. Such reactions can result in additional
solubilization of phosphorus [4-14],
PRECIPITATION AND DISSOLUTION
Metals dissolve or precipitate in response to the changing aquatic
environment. In anaerobic waters, insoluble ferric iron is converted to
ferrous iron, which readily dissolves. In the presence of sulfide,
which is common in anaerobic sediments, ferrous iron is precipitated as
iron sulfide [4-29, 4-41]. Other metals, including cadmium, copper,
lead, mercury, silver and zinc, form insoluble sulfides under reducing
63
-------
conditions common in wetlands [4-15, 4-16, 4-38], In aerobic
environments, aluminum, cadmium, chromium, iron, manganese and zinc form
o.xides and hydrox-ides [4-15, 4-16, 4-38, 4-51]. Dissolution of minerals
that are more soluble at low pH often occurs in organic-rich sediments
when acids are released by partial degradation of organic matter [4-24].
phosphate release in the aquatic environment This process is a common
cause of phosphate release in the aquatic environment [4-7, 4-14].
OXIDATION AND REDUCTION
Oxidation and reduction always occur simultaneously. Oxidation is the
loss of electrons and reduction is the gain of electrons. Metals are
common catalysts for oxidation^reduction reactions, but more frequently
enzymes associated with microorganisms catalyze transformations of this
type. For some organic compounds oxidation reduction reactions are
by exposure to light (in wetland environments, sunlight). In
, water must be included to effect a balance, but this occurs
in aqueous solutions* Each of these reactions .is described
initiated
some cases,
naturally
below.
Oxidation
Oxidation can occur in either the presence or absence of oxygen.
Autooxidation is the reaction of oxidizable material with molecular
o*ygen. An example important to wetlands is the oxidation of hydrogen
sulfide to sulfates. This reaction is catalyzed in both fresh and salt
waters by metals such as cobalt, copper, iron, manganese and nickel
£4-22], Oxidation of. organic matter is constantly taking, place in all
wetland systems. The most important route is by biological mediation.
When oxygen is present, the degradation can proceed completely so that
carbon dioxide and water are the products. Some naturally occurring
organic matter resist complete oxidation and refractory substances
remain. An important mechanism for the release of metals to water is
the oxidation of the organic portion of particulate matter having
associated trace metals.
In wetland sediments having high organic matter content, molecular
oxygen is usually not present. Microbes can use nitrate and sulfate
oxygen in these circumstances to oxidize organic matter. In general,
readily biodegradable organic matter is anaerobically oxidized through a
series o.f microbial transformations so that methane and carbon dioxide
are the final products [4-23],
Other compounds are commonly oxidized in wetlands. Organic nitrogen is
sequentially oxidized by bacteria in aerobic environments to ammonia,
nitrite and nitrate [4-2]. Iron sulfide and pyrite are oxidized
biologically to elemental sulfur, thiosulfate, polythiosul fate, sulfite,
and sulfate [4-23, 4-41], Arsenite is oxidized by microorganisms to
arsenate [4-42]. Soluble ferrous ions, which diffuse into aerobic zones
64
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from underlying sediments, are oxidized to ferric oxides and hydroxides
[4-30, 4-43] and chromium (III), which is common in rocks, is slowly
oxidized to chromium (V!) [4-8], Other metals are similarly oxidized
[4-43].
Reduction
Chemical reduction of organic matter primarily occurs within plants and
photo synthetic bacteria and is made possible by solar energy captured in
photosynthesis. Chemoautotrophic bacteria are an exception to this
reduction process and are of lesser significance. These processes are
not discussed here as they are not pollutant removal mechanisms.
Several compounds are reduced in anoxic environments to provide oxygen
for the oxidation of organic matter. Usually either nitrate or sulfate
is the oxygen-rich agent that is reduced. Nitrate is reduced to
nitrite, then to gaseous elemental nitrogen; sulfate is reduced to
hydrogen sulfide, iron sulfide, and pyrite. Under anoxic conditions,
some metals are reduced to lower oxidation states.
Hydrolysis
One of the most important hydrolytic reactions in natural waters is the
conversion between ammonia and ammonium. When the water molecule is
split, the hydrogen ion unites with ammonia while the hydroxyl radical
remains in solution. This tends to raise the pH and provide a more
favorable environment for biological oxidation of nitrogen [4-2].
Hydrolysis of some organic compounds occurs in wetlands. This reaction
is particularly significant for materials that may be toxic to
microorganisms. Hydrolysis may be a mechanism for removal of
chlorinated alkanes from waters although the process may take months
[4-10], Metals are sometimes necessary to catalyze hydrolysis. For
example, cobalt'and copper can catalyze the hydrolysis of glycine methyl
ester [4-22]. A few other illustrations of the hydrolysis of compounds
having environmental significance are:
(1) The acid-based catalyzed reactions of phthalate esters
and phosphate esters to yield organic acids and alcohols,
which are biodegradable [4-13];
(2) Hydrolysis of the insecticides methoxychlor and
dichiorodiphenyltr1chi oroethane (DDT) to
dichlorodiphenylethylene (DDE) [4-60];
(3) Hydrolysis of 2,4-D esters to phenols [4-62],
Photochemical Reaction
The two principal types of photochemical reactions that occur in natural
water bodies are [4-13, 4-61]:
65
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(1) Direct -photolysis, which is the absorption of light by a
compound, followed by its disintegration to more reactive
fragments. When one of the free radicals created is the
singlet oxygen, which is a more reactive oxidizer tha'n
mol-ecular oxygen, the process is called photochemical
oxidation.
(2) Photosensitized oxidation, which is also called indirect
or sensitized photolysis. This occurs when the singlet
oxygen formed by photolysis initiates the oxidation of a
substance other than the originally excited compound.
The extent of photochemical reactions is a function of the solar
spectral irradiance at the water surface, the transfer of the light from
air to water, and transmission through the water. In wetland waters,
attenuation of light by dissolved natural organics can restrict these
reactions to the upper layers. Scattering of light-by suspended matter
is usually much less important than absorbance [4-61], Because the
intensity of light usually drops with depth precipitously in wetland
waters, the surface film is where most photochemical reactions take
place [4-28, 4-62].
A number -of examples illustrate photochemical reactions that can
participate in the removal of compounds of environmental concern:
(1) EDTA is rapidly photodegraded in both acidic and basic
waters [4-31];.;
(2) Ultraviolet irradiation of hydrocarbons found in to. 2
fuel oil produces relatively soluble .oxygenated
compounds," ind uding reactive peroxides, phenols and
carbonyl compounds [4-28];
(3) Photodegradation can shorten the life of unsaturated
chlorinated alkanes but probably does not occur for their
saturated counterparts [4-10.];
(4) The polynuclear aromatic hydrocarbon, benzanthracene, is
photodegraded in salt waters, [4-21];
(5) Al tho ugh usual 1 y slow, many pesticides undergo
photodegradation including 2,4-D esters [4-61, 4-25],
malathion [4-59], methoxychlor and DDT [4-61].
66
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REFERENCES
4-1. Anon. Perhaps Earth Materials Can Attenuate Polybrominated
Biphenyl. Environ. Sci. Technol. 14(9):1020, 1980.
4-2. Bansal, M.K. Nitrification in Natural Streams. Jour. Water
Poll. Control Fed. 48(10):2380, 1976.
4-3. Catanzaro, E.J. Some Relationships between Exchangeable Copper
and Lead and Particulate Matter in a Sample of Hudson River
Water. Environ. Sci. Technol. 10(4):386, 1976.
4-4. Chase, R.R.P. Settling Behavior of Natural Aquatic Particulates.
Limnol. Oceanogr. 24(3):417, 1979.
4-5. Choi, W.W. and K.Y. Chen. Associates of Chlorinated Hydrocarbons
with Fine Particles and Humic Substances in Nearshore Surficial
Sediments. Environ. Sci. Technol. 10(8):782, 1976.
4-6. Cohen, Y., W. Cocchio and D. Mackay. Laboratory Study of
Liquid-Phase Controlled Volatilization Rates in the Presence of
Wind Waves. Environ. Sci. Technol. 12(5):553, 1978.
4-7. Cowen, W.F. and G. F. Lee. Phosphorus Avai 1 abi 1 i ty i n
Particulate Materials Transported by Urban Runoff. Jour. Water
Poll. Control Fed. 48(3):580, 1976.
4-8. Cranston, R.E. and J.W. Murray. Chromium Species in the Columbia
River and Estuary. Limnol. Oceanogr. 25(6):1104, 1980.
4-9. Crecelius, E.A., M.H. Bothner and R. Carpenter. Geochemistries of
Arsenic, Antimony, Mercury, and Related Elements in Sediments of
Puget Sound. Environ. Sci. Technol. 9(4):325, 1975.
4-10. Dilling, W.L., N.B. Tefertiller and G.J. Kallos. Evaporation
Rates and Reactivities of Methylene Chloride, Chloroform,
1,1,1-Trichloroethane, Trichloroethylene, Tetrachloreoethyl ene ,
and Other Chlorinated Compounds in Dilute Aqueous Solution.
Environ. Sci. Technol. 9(9):833, 1975.
4-11. Eisenreich, S.J., A.W. Elzerman and D.E. Armstrong. Enrichment
of Micronutrients, Heavy Metals and Chlorinated Hydrocarbons in
Wind-Generated Lake Foam. Environ. Sci. Technol. 12(4):413,
1978.
4-12. Elzerman, A.W. and D.E. Armstrong. Enrichment of Zn, Cd, Pb, and
Cu in the Surface Microlayer of Lakes Michigan, Ontario, and
Mendota. Limnol. Oceanogr., 24(1):133, 1979.
4-13. Ember, L.R. Tracking the Elusive Pollutant. Environ. Sci.
Technol. 10(7):640, 1976.
67
-------
4-14. FiHos, J. and W.R. Swanson. The Release Rate of Nutrients from
River and Lake Sediments. Jour. Water Poll. Control Fed.
47(5):1032, 1975.
4-15. Framson, P.E. and J.A. Leckie. Limits of Co precipitation of
Cadmium and Ferrous Sulfide. Environ. Sci. Techol. 12(4): 464,
1978.
4-16. Gambrell, R.P., R.A. Khalid and W.H. Patrick, Jr. Chemical
Availability of Mercury, Lead, and Zinc in Mobile Bay Sediment
Suspensions as Affected by pH and Oxidation-Reduction Conditions.
Environ. Sci. Techno!. 14(4):431, 1980.
4-17. Gearing, P.J., J.N. Gearing, R.J. Pruell., T.L. Wade and J.G.
Quinn. Partitioning of No. 2 Fuel Oil in Controlled Estuarine
Ecosystems. Sediment and Suspended Particulate Matter.. Environ.
Sci. Technol. 14(9):1129, 1980.
4-18. Gerba, C.P., G. Wallis and.J;L. Welnick. Viruses in Water: the
Problem, Some Solutions. Environ. Sci. Technol. 9(13): 1122,
1975.
4-19. Gordon, D.C., Jr., P.O. Keizer, W.R. Hardstaff and D.G. Aldous.
Fate of Crude Oil on Seawater Contained in Outdoor Tanks.
Environ. Sci. Technol. 10(6):580-584, 1976.
4-20. Hannah, R.P., A.T. Simmons and G.A. Moshiri.
Nutrient-Productivity Relationships in a Bayou Estuary. Jour.
Water Poll. Control Fed. 45(12):2508, 1973.
4-21. Hinga, K.R., M.E.Q. Pilson, R.F. Lee, J.W. Farrington, K. Tjessem
and A.C. Davis. Biogeochemistry of Benzanthracene in an Enclosed
Marine Ecosystem. Environ. Sci. Technol. .14(9):1136, 1980.
4-22. Hoffman, M.R. Trace Metal Catalysis in Aquatic Environments.
Environ. Sci. Technol. 14(9):1061, 1980.
4-23. Howarth, R.W. and J.M. Teal. Sulfate Reduction in a New England
Salt Marsh. Limnol. Oceanogr. 24(6):999, 1979.
4-24. Huang,. C.P., H.A. Elliot and R.M. Ashmead. Interfacial Reactions
and the Fate of Heavy Metals in Soil-Water Systems. Jour. Water
Poll. Control Fed. 49(5):744, 1977.
4-25. Isensee, A.R. and G. E. Jones. Distribution of 2,3,7,8-
Tetrachlorodibenzo-p-dioxin (TCDD) in an Aquatic Model Ecosystem.
Environ. Sci* Technol. 9(7):668, 1975.
4-26. Jackson, G.A. and J.J. Morgan. Trace Metal-Chelator Interactions
and Phytoplankton Growth in Seawater Media: Theoretical Analysis
and Comparison with Reported Observations. Limnol. Oceanogr.
23(2):268, 1978.
68
-------
4-27. Jonas, R.B. and F.K. Pfaender. Chlorinated Hydrocarbon
Pesticides in the Western forth Atlantic Ocean. Environ. Sci.
Techno!. 10(8):770, 1976.
4-28. Larson, R.A., L.L. Hunt and D.W. Blankenship. Formation of Toxic
Products from a #2 Fuel Oil by Photo Oxidation. Environ. Sci.
Techno!. 11(5):492, 1977.
4-29. Leenheer, J.A., R.L. Malcolm and W.R. White. Investigation of
the Reactivity and Fate of Certain Organic Components of an
Industrial Waste after Deep-Well Injection. Environ. Sci.
Technol. 10(5):444, 1976.
4-30. Lijklema, L. Interaction of Orthophosphate with Iron (III) and
Aluminum Hydroxides. Environ. Sci. Technol. 14(5):537, 1980.
4-31. Lockhart, H.B., Jr. and R.V. Blakeley. Aerobic Photodegradation
of Fe(III)-(Ethylened1nitri!o) tetraacetate (Ferric EDTA).
Environ. Sci. Technol. 9(12):1034, 1975.
4-32. Lu, J.C.S. and K. Y. Chen. Migration of Trace Metals in
Interfaces of Seawater and Polluted Surficial Sediments.
Environ. Sci. Technol. 11(2):174, 1977.
4-33. McElroy, M.B., J.W. Elkins, S.C. Wbfsy, C.E. Kolb, A.P. Duran and
W.A. Kaplan. Production and Release of N0? from the Potomac
Estuary. Limnol. Oceanogr. 23(6):1168, 1978.
4-34. McKnight, D.M. and F.M. M. Morel. Release of Weak and Strong
Copper-Complexing Agents by Algae. Limnol. Oceanogr. 24 (5): 823,
1979.
4-35. McKnight, D.M. and F.M.M. Morel. Copper Complexation by
Siderophores from Filamentous Blue-Green Algae. Limnol.
Oceanogr. 25(1):62, 1980.
4-36. Mantel!, J.M., D.A. Richert and F.R. Siege!. PCB's in Suburban
Watershed, Reston, Va. Environ. Sci. Technol. 9(9):872, 1975.
4-37. Miller, S. Adsorption on Carbon: Solvent Effects on Adsorption.
Environ. Sci. Technol. 14(9):1037, 1980.
4-38. Morel, F.M.M., J.C. Westall, C.R. O'Melia and J. Morgan. Fate of
Trace Metals in Los Angeles County Wastewater Discharge.
Environ. Sci. Technol. 9(8):756, 1975.
4-39. Nriagu, J.O. and R.D. Coker. Trace Metals in Humic and Fulvic
Acids from Lake Ontario Sediments. Environ. Sci. Technol.
14(4):443, 1980.
4-40. O'Melia, C.R. Aquasols: The Behavior of Small Particles in
Aquatic Systems. Environ. Sci. Technol. 14(9):1052, 1980.
69
-------
4-4.1. .RanMw, .J.F. and J.J. Morgan. Dissolution of Tetragonal Ferrous
Sulfide (iMackinawite) in Anoxic Aqueous Systems. 2. Implications
for the Cycling of Iron, Sulfur, and Trace Metals. Environ. Sci.
Techno!. 14(2):183, 1980.
4-42. Pierce, M.L. and C.B. Maore. Adsorption of.Arsenite on Amorphous
Iron Hydroxide from Dilute Aqueous Solution. Environ. Sci.
Techno 1. 14(2):.214, 1980.
4-43. Rohatgi, N. and K.Y. Chen. Transport of Trace Metals by
Suspended Particulates on Mixing with Seawater. Jour. Water
Poll. Control Fed. 47(9):2298, 1975.
4-44. Rosenfeld, J.K. Ammonium Adsorption in Nearshore Anoxic
Sediments. Limnol. Oceanogr. 24(2):356, 1979.
4-45. Rosenfeld, J.K. Ami no Acid Diagenesis and Adsorption in
Nearshore Anoxic Sediments. Limnol. Oceanogr. 24(6):1014, 1979.
4-46. Saar, R..A. and J.H. Weber. Lead(II) - Fulvic Acid Complexes.
Conditional Stability Constants, Solubility, and Implications for
Lead(II) Mobility. Environ, Sci. Techno!. 14(6):877, 1980.
4-47. Sayler, G.S. and R.R. Co!we'!!. Partitioning of Mercury and
Polychlorinated Biphenyl by Oil, Water, and Suspended Sediment.
Environ. Sci. Technol. 10(12):1142, 1976.
4-48. Shelton, T.B. and J.V.. Hunter. Aerobic Decomposition of Oil
Pollutants in Sediment. Jour. Water Poll. Control Fed.
46{9):2172, 1974.
4^49. Shelton, T.B. and J.V. Hunter. Aerobic Decomposition of Oil
Pollutants in Sediments. Jour. Water Poll. Control Fed.
46(9):2172, 1974.
4-50. Shin, E. and P.A.KrenkeT. Mercury Uptake by Fish and
Biomethyl ation Mechanisms. Jour. Water Poll. Control Fed.
48(3):473, 1976.
4-51. Sridharan, N. and G.F. Lee. Phosphorus in Lower Green Bay, Lake
Michigan. Jour.. Water Poll. Control Fed. 46(4):684, 1974.
4-52. Stumm, W. Chemical Interaction in Particle Separation. Environ.
Sci. Technol. 11(12):1066, 1977.
4-53. Stumm, W. and J.J. Morgan. Aquatic Chemistry.
Wiley-Interscience, New York, N.Y., 1970.
4-54. Sunda, W.G. and J.A.M. Lewis. Effect of Complexation by Natural
Organic Ligands on the Toxicity of Copper to a Unicellalar Alga,
Monochrysis lutheri. Limnol. Oceanogr. 23(5):870, 1978.
70
-------
4-55. Truong, L. and C.R. Phillips. Freezing of Oil-Water and
Oil-Saline Emulsions. Environ. Sci. Technol. 10(5):482, 1976.
4-56. Tuschall , J.R., Jr. and P.L. Brezonik. Characterization of
Organic Nitrogen in Natural Waters: Its Molecular Size, Protein
Content, and Interactions with Heavy Metals. Limnol. Oceanogr.
25(3):494, 1980.
4-57. Van Vleet, E.S. and J.G. Quinn. Input and Fate of Petroleum
Hydrocarbons Entering the Providence River and Narragansett Bay
from Wastewater Effluents. Environ. Sci. Technol. 11(2):1086,
1977.
4-58. Williamson, K. and P.L. McCarty. A Model of Substrate
Utilization by Bacterial Films. Jour. Water Poll. Control Fed.
48(6):9, 1976.
4-59. Wolfe, N. L., R.G, Zepp., J.A. Gordon, G.L. Baughman and D.M.
Cline. Kinetics of Chemical. Degradation of Malathion in Water.
Environ. Sci. Technol. 11(1):88, 1977. .
4-60. Wolfe, N. L., R.G. Zepp, D.F. Paris, G.L. Baughman and R.C.
Hollis. Methoxychlor and DDT Degradation in Water: Rates and
Products. Environ. Sci. Technol. 11(12):1077, 1977.
4-61. Zepp, R.G. and D.M. Cline. Rates of Direct Photolysis in Aquatic
Environment. Environ. Sci. Technol. 11(4):359, 1977.
4-62. Zepp, R.G., N.L. Wolfe, J.A. Gordon and G.L. Baughman. Dynamics
of 2,4-D Esters in Surface Waters: Hydrolysis, Photolysis, and
Vaporization. Environ. Sci. Technol. 9(13):1144, 1975.
4-63. Eaton, A. Observations on the Geochemistry of Soluble Copper,
Iron, Nickel and Zinc in the San Francisco Bay Estuary. Environ.
Sci. Technol. 13(4):424, 1979.
4-64. Morris, F.A., M.K. Morris, T.S. Michaud and L.R. Williams.
Meadowland Natural Treatment Processes in the Lake Tahoe Basin:
A Field Investigation. U.S. EPA, Environmental Monitoring
Systems Laboratory, Las Vegas, Nev., 1980.
4-65. Tilton, D.L. and R.H. Kadlec. The Utilization of a Freshwater
Wetland for Nutrient Removal from Secondarily Treated Wastewater
Effluent. Jour. Environ. Qual. 8(3):328, 1979.
4-66. Blumerj K. The Use of Wetlands for Treating Wastes - Wisdom in
Diversity? In: Environmental Quality through Wetlands
Utilization. "Proceedings from a Symposium Sponsored by the
Coordinating Council on the Restoration of the Kissimee River
Valley and Taylor Creek-Nubbin Slough Basin, Tallahassee, Fla.,
February 29-March 2, 1978.
71
-------
4-67. Sloey, .W. E., F.L. Spangler and C.W. Fetter, Jr. Management of
Freshwater Wetlands for Nutrient Assimilation. In: Freshwater
Wetlands: Ecological Processes and t Management Potential, R.E.
Good, D.F. Whigham and R.L. Simpson (eds.), Academic Press, New
York, N.Y., 1978.
4-68. Sutherland, J.C. and F.B. Bevis. Reuse of Municipal Wastewater
by Volunteer Freshwater Wetlands. Proceedings, Water Reuse
Symposium, Vol 1, Washington, D.C., March, 1979.
4-69. Vanoni, V.A. (ed). Sedimentation Engineering. American Society
of Civil Engineers, New York, 1979.
4-70. Hickok, E.E. * M.C. Hannaman and N.C. We nek. Urban Runoff
Treatment Methods: Volume I - Non-Structural Wetland Treatment.
EPAr600/2-77-217, Cincinnati, Ohio, 1977.
4-71. Isirimah, N.O. and D.R. Keeney. Contribution of Developed and
Natural Marshland Soils ;to Surface and Subsurface, Water ..Qual ity.
Technical Completion Report Project Number OWRR A-049-WIS, Water
Resources Center, University of Wisconsin,, Madison, Wis., 1973.
4-72. Zoltek, J., Jr., S.E. Bayley et al. Removal of Nutrient from
Treated Municipal Wastewater by Freshwater Marshes. Progress
Report to City of Clermont, Fla., September, 1978.
4-73. Sawyer, C.N* and P.L. McCarty. Chemistry for Sanitary Engineers.
McGraw-Hill .Book Co.,-.New York, N.Y., 1967.
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SECTION 5
BIOCHEMICAL POLLUTANT REMOVAL MECHANISMS IN VEGETATIVE SYSTEMS
Vegetative systems have attracted attention as natural sinks for
contaminants and as potential components for wastewater treatment
systems [5-1 through 5-10]. Wetland systems are characterized by:
o high plant productivity and nutrient needs;
o high decomposition activity;
o large adsorptive areas in the substrates;
o low oxygen content of the sediments.
Dryland or upland systems are characterized by:
o high plant productivity and nutrient requirements under
irrigation;
o large adsorptive areas in the substrates;
o high physical, chemical and microbial activity in the soil
mantle; '
o periodic reaeration of the soil layers.
These properties seem to provide vegetative systems with the ability to
degrade and eliminate contaminants in wastewaters.
Changes in water quality in a variety of natural habitats, such as
freshwater marshes, bogs, swamps, brackish and saltwater marshes, as
well as artificially constructed wetland systems and managed grassland
systems, have been studied. Although each habitat differs, these
systems have been generally found to remove nitrogenous and phosphorus
nutrients from wastewaters. Suspended and particulate matter are
filtered out by plant roots or settle on the plant and soil surfaces.
Petroleum hydrocarbons accumulate on surface soils and may be actively
broken down. Chlorinated hydrocarbons show strong attractions to
sediments and may be degraded by microorganism activity. Other
contaminants that may be reduced are coliform bacteria and wastes that
deplete oxygen from the system (as measured by BOD). Although little is
known about the upper limits of wetland and dryland waste-processing
abilities, studies of systems receiving pollutants continuously show
that vegetative systems can function well even in severely polluted
areas.
-------
Vegetative systems possess a variety of ecological features that adapt
them to gradual environmental changes. These features can also allow
it-he vegetative systems to survive the added stresses of processing waste
'effluents op to some limits. Under certain conditions, wastewater
input, particularly the nutrient components, can enhance the
productivity of a system.
Since the majority of waterborne contaminants are adsorbed onto
particulate matter, sedimentation of particulates effectively scrubs the
water column, and prevents dispersal of the pollutants. These
organic-rich sediments are further bound in place by plant roots. The
tendency for these sediment layers to become anaerobic is probably the
major factor involved in the retention of various chemical species
[5-10]. Reducing environments allow the conversion of heavy metals into
relatively insoluble sulfides and promote the removal of nitrate
nitrogen through denitrification.
Vegetative .systems possess a variety of mechanisms for obtaining
nutrients and other elements from their environments under changing
conditions. Through interaction with the various soil layers, water and
air interfaces, plants can increase the overall capacity of a system to
retain or remove pollutants. Since the primary mechanisms for pollutant
removal in a wetland system are physical and chemical interactions that
cause the contaminants to settle or be drawn out of the water column
into the sediments, plant uptake of poll utants, particul arly from the
sediments, frees more exchange sites for further pollutant interaction
and accumulation. Some researchers theorize that pollutant removal in
.aquatic systems is 'due, primarily, to bacterial metabolism and physical'
sedimentation (5-224).. However, even they concede that plants provide
surfaces for bacterial growth, filtration and adsorption of solids,
attenuation of sunlight and nutrient absorption to retard growth of
algae, and uptake of heavy metals. The biochemical processes related to
wastewater renovation that will be discussed in this section are:
o pollutant uptake processes;
o plant adaptation, mechanisms; .
o nutrient cycling;
o heavy metal removal potentials;
o tolerances to other pollutants.
POLLUTANT UPTAKE PROCESSES
Pollutants in ionic form can be actively taken up by plants and
accumulated in concentrations in excess of their environment. Plant
cell membranes are not permeable to free ions of elements. Ions can
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only be transported across the cell membrane into the plasma through
carriers which are active subunits of the membrane. Carriers have been
hypothesized to be enzymes in that they have active sites that are
specific for particular types of ions. Various carrier-transport
mechanisms appear to function at different temperature levels [5-11],
Environmental conditions, such as increased light, temperature and
carbohydrate energy sources, generally promote ion transport, whereas
anaerobic conditions may inhibit absorption of specific ions. The
physical and chemical mechanisms occurring within an aquatic environment
that immobilize, liberate or facilitate uptake of pollutants were
discussed in Section 4.
The pollutant uptake processes to be discussed below include:
o uptake through the plant-soil interface;
o uptake through the plant-water interface;
o translocation through plant systems;
o differential uptake vs nonspecific uptake;
o immobilization in the litter zone.
Uptake through Plant-Soil Interface
Vascular plants actively absorb ions from the soil through the root
systems. Rooted aquatic plants can also absorb ions through roots,
rhizomes and holdfasts. Buried portions of shoots and leaves are also
capable of uptake, particularly of nutrients [5-12]. Uptake capability
is usually directly proportional to the volume of belowground roots
except in some submerged and floating plant species which have poor root
systems.
Upland vegetation requires an aerated soil zone around the roots for
proper plant growth. The rhizosphere or immediate zone around the roots
shelters aerobic, nitrifying bacteria which convert ammonia-nitrogen to
nitrate-nitrogen, the form most readily taken up by plants. Wetland
vegetation, on the other hand, typically grows in saturated anaerobic
substrates. These conditions favor arnmonification and denitrification
which result in high ammonia-nitrogen and Tow nitrate-nitrogen levels in
the sediments and water. Wetland vegetation is typically adapted to use
not only nitrate but also ammonia and ammonium as nitrogen sources.
In a wetland or aquatic environment, pollutants such as heavy metal ions
can adsorb onto particulates or form complexes with inorganic phosphorus
and settle down to the sediment layers. Concentrations of these
pollutants are highest in the top layers of sediments and, unless they
are immobilized into nonsoluble forms, provide a rich uptake source for
vascular aquatic plants. The various processes immobilizing pollutants
will be discussed later in this section.
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Uptake through Plant-Water Interface
Mast species..crf wetland vegetation are able to absorb some nutrients and
ionic compounds from the water via shoots and leaves, although the
primary uptake would still be through the roots at the plant-soil
interface. Submerged plant species, particularly those which have weak
or poorly-developed root systems, are capable of absorbing the bulk of
their nitrogen requirements directly through the leaves [5-13, 5-14,
5-15]. Uptake of nutrients and other compounds is probably affected by
the same factors that influence other plant physiologic processes, such
as light, temperature and dissolved oxygen.
Translocat-ion through Plant Vascular System
Movement of nutrients and other compounds from the root uptake sites
through a plant vascular system can increase the capacity of a
vegetative system to adsorb pollutants. The most rapid uptake usually
occurs during the growing season when nutrients are translocated from
the roots to the shoots and leaves. Peak uptake generally coincides
with, the period of peak biomass production [5-16, 5-17, 5-18].'"-
With the death of emergent and aquatic vegetation in the fall
(senescence), translocation from aboveground to belowground parts and
winter storage of some nutrients and other compounds occur in wetland
vegetation [5-16, 5-19, 5-20]. At the start of the next growing season,
depending on the species, nutrient levels may have decreased in the
roots and rhizomes and become concentrated in the shoots, probably
preparatory for the .period of new growth. Thus, at the start of the;
gro.wing season, the aboveground parts (the shoots) will contain the
'highest nutrient concentrations [5-16, 5-19, 5-21]. Whether these high
concentrations are sustained solely from the belowground plant resources
or are a result of immediate uptake is not certain. Data indicate that
root uptake could be sufficient to account for these concentrations
[5-19]. It should be noted that peak accumulation in belowgro.und parts
generally does not occur until aboveground parts have reached their peak
concentrations [5-16],
In some fast-growing plant species such as grasses, uptake of pollutants
such as heavy metals increases with increasing heavy metal
concentrations in the soil and water [5-22, 5-23], In reed canarygrass,
lead is translocated from the roots to the aboveground parts. However,
unlike other emergent macrophytes, translocation back to the belowground
parts daes not o.ccur when the plant senesces in the fall. Instead, as
Che aboveground mass falls to the ground and decomposes, the accumulated
pollutants and other compounds are gradually released back to the soil
and water.
Differential Uptake vs. Nonspecific Uptake
Certain plants accumulate dissolved materials, including trace
contaminants, that are not required for plant growth or function. This
nonspecificity is a function of general nutrient uptake processes where
76
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some minerals, such as strontium and calcium, are interchangeable ions
in plant metabolism. In other cases, the accumulation of heavy metals
without apparent toxic effect may be due to the presence of chelating
compounds which combine with the metal ions to form harmless complexes.
An example is Potamogeton pectinatus, a lead-tolerant plant which takes
up lead readily.Incorporation into the cell wall renders the lead
inactive and harmless to the plant [5-24],
Trace contaminants can be taken up and preferentially stored in
different plant parts. In pondweed (Potamogeton spp.), most heavy
metals tend to concentrate in the roots and rhizomes, while zinc
accumulates in the stems and leaves. Tolerance of a heavy metal varies
for any single plant species and tolerance of one metal does not
necessarily indicate tolerance for others. In general, emergent aquatic
plants have lower heavy metal content than floating or submerged plants
[5-25].
Uptake and Immobilization by the Litter Zone
As discussed,previously* some species of wetland vegetation do not
translocate nutrients and other compounds to the belowground parts when
the stems and leaves die in the fall. The dead plant matter eventually
falls to the ground or surface waters and breaks down to form an
extensive litter zone in some marshes. Dead, but not decomposed,
cordgrass litter in a saltwater marsh was found to be able to adsorb
heavy metals directly from the water. Decomposing litter also releases
humic acids which act as metal chelators and effectively immobilize
these pollutants. Therefore, the organic litter layer in these grass
stands acted as a sink accumulating more heavy metals than the living
plant mass [5-26, 5-27, 5-28, 5-29].
ADAPTATION MECHANISMS
Vegetative systems, particularly wetlands, are often subjected to widely
changing environmental conditions. Mechanisms for coping with salinity
and temperature extremes as well as drought and water saturation
conditions in the growth medium have evolved in different plant types
and species. Through these mechanisms, some plants can become tolerant
of pollutant inputs. Some mechanisms may be adapted to a specific
pollutant or pollution condition.. . .
Anaerobic Respiration
Wetland systems, by definition, have high water tables at or near the
soil surface. These water-saturated soils promote anaerobic conditions
at least during some portions of the year and give rise to specific
physiological and anatomical adaptations in wetland vegetation. By
contrast, in upland systems, prolonged soil saturation and the
subsequent development of anaerobic conditions will eliminate most
upland vegetation.
77
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I,n emergent wetland vegetation, the aerenchyma tissue allows for
exchange of gases between various plant parts, and is vital to root
aeration under anaerobic conditions [5-30], Laing [5-31, 5-32] has.
demonstrated that aquatic plants have the ability to respire both
aerobically and anaerobically. Of the two types of metabolism,
anaerobic respiration can be sustained at a higher rate and for longer
periods in aquatic plants but involves a concomitant higher consumption
in food material. .Other investigations have indicated that the high
levels of carbon dioxide which form in the rhizomes of some aquatic
plants (aerobically and anaerobically) increase plant photosynthesis
[5-33]. However, anaerobic conditions may also inhibit the absorption
of certain ions by roots and other vegetative parts [5-34],
Specialized Plant Functions
o Root Interactions
Root aeration during the winter months may provide a buffer from toxic
substances .present in anaerobic substrates, such as hydrogen sulfide or
iron and manganese [5-35.]. Seidel [5-36] hypothesized that root
excretions may deter root decay induced by bacteria and fungi, and
showed that root excretions of some aquatics destroyed disease bacteria
while preserving benign populations* An additional function suggested
by Seidel.which.has particular significance for wastewater application,
is the formation of a "protective space" in the root zone allowing
benign bacteria to.survive during high loadings of heavy metals or other
toxic elements,. and to subsequently recoldnize the area for continued
functioning.
o Plant Adaptations
Plant environments which are subject to widely ranging or extreme
salinity conditions, such as salt marshes and alkaline salt flats, often
have physiological adaptations which allow,plants to cope with increased
concentrations of salts in the water and soil. These adaptations, in
some cases, may also: allow the plants to tolerate dissolved contaminants
to some unspecified level; Reeds (Phragmites spp.) inhabit areas with a
wide range of salinities (0.2 to 40 ppt) [5-37, 5-38]. Structural
adaptations for salinity tolerance include starch accumulation, thicker
leaves [5-37] and production of different types of fiber [5-39], The
plant also produces more aboveground runners In saline than in
freshwater erivi ronments, although it is not clear whether this is an
avoidance or opportunistic action.
Proline accumulation has been noted in some plants including rushes
(Juncus spp.) growing in saline environments. Accumulation of this amino
acid may regulate plant osmotic balance with the external medium [5-40],
Reduction of aboveground plant parts to fleshy stems and tubercles, such
as in pickleweed (Salicornia spp.), is another adaptation mechanism for
dealing with increased salinities and surplus concentrations of
78
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materials within plant tissue. Pickleweed can grow in alkaline salt
flats where salinities may reach 60 to 80 ppt. Studies in a brackish
marsh in California [5-41] have shown the ability of perennial
pickleweed to absorb significant quantities of heavy metals beyond soil
and water concentrations. The concentrated salts are stored in the more
recent plant growth "pickle" parts. At the end of the growing season,
Salicornia is able to shed the distal plant parts that, by then, are
highly concentrated in salts and are discolored pink or red. By this
process, the plant is rid of excess accumulations which eventually
recycle back into the wetland system.
o Transformation to Nontoxic Forms
Heavy metals and other trace contaminants may be taken up by plants due
to the lack of complete specificity of plant absorbance mechanisms. The
ability to accept substances that may be potentially toxic to plant
functions suggests the existence of a plant compound or compounds which
combine with the contaminant to render it nontoxic [5-42]. Thus, some
plants may contain chelating agents that would form complexes with
specific metal ions, effectively immobilizing the pollutant until the
plant matter breaks down.
o Surplus Accumulation
The concept of "luxury uptake" of nutrients such as phosphorus and
nitrogen has been cited in some studies where plants absorb more
nutrients than are needed for plant metabolism. This tends to occur in
situations where a particular dissolved substance, required for plant
function, is available in higher than normal concentrations and growth
conditions are optimal. A University of Michigan study [5-43] showed
higher phosphorus concentrations and greater productivity of algae
growing near a treated sewage discharge pipe, which can probably be
explained by luxury uptake. Most of the surplus phosphorus, however,
was apparently immobilized within the algae during growth. Release of
the surplus accumulations did not occur until plant decomposition, when
the algal phosphorus was converted in the sediments to inorganic
phosphorus by bacterial action [5-44], The action of immobilization and
accumulat ion of surplus substances is similar in concept to the
attenuation and accumulation of toxic ions discussed previously. The
mechanics and the evolution of these processes are not well understood.
However, as discussed later, they do appear to be specific for selected
ions, such as heavy metals, in certain plants.
NUTRIENT CYCLING RELATED TO WASTEHATER RENOVATION
Nutrient cycling and potential pathways for some wetland and upland
habitats are fairly well known. This knowledge promotes an overall
understanding of nutrient movement through an ecosystem and allows
predictions for the general outcome of selected parameters under certain
conditions. However, quantifying nutrient movements between various
79
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components of a cycle is extremely difficult and of limited use, as no
two ecosystems, even artificial ones, would be likely to have the same
environmental conditions. Although several investigations have yielded
percentages or quantities of nutrients retained per area, actual
retention effectiveness by compartment and exchange rates have generally
not been adequately determined. Thus, in the review of nutrient cycling
through vegetative systems, nutrient pathways and their significance in
various systems can be discussed, but the nutrient retention or removal
potential can only be presented in terms of total systems.
The major nutrients of concern in this review are nitrogen and
phosphorus, since lack of these elements is often a limiting factor in
the productivity of a vegetation system, and wastewaters are usually
rich in these nutrients. Other .macronutrients include sulfur,
potassium, calcium and magnesium, which are generally adequately
supplied by the natural environment. Micronutrients include the trace
elements iron, manganese, bordn, zinc, copper, molybdenum and chlorine,
which are often present in wastewaters beyond plant requirement levels.
When accumulated in excess, these micronutrients can cause phytotoxicity
(damage to plants).'These trace elements are reviewed in a subsequent
part of this section.
Nitrogen Cycles 1n Vegetative Systems
The predominant forms of nitrogen entering wetlands are organic
nitrogen, ammonium-nitrogen (NH^-N) and nitrate-nitrogen (NOj-N) [5-45].
Nitrogen sources include contributions from ground waters and surface
runoff waters, and to some extent from atmospheric nitrogen fixation by
some algae and bacteria. Ground-water contributions vary with the
extent of ground-water infiltration, nutrient levels in the
gro und-water, and the extent of nutrient transformation during
Infiltration (particularly through sediments) [5-46]. Ground-water
nitrogen inputs to several marshes studied were generally low, ranging
from negligible in a Michigan peatland [5-47] to 0.8 g/(m2)(yr) in a
Wisconsin marsh [5-19] to several mg/1 nitrate-nitrogen in another
Wisconsin marsh [5-47].
Surface runoff contributions vary as a function of watershed size, and
]and use practices such as urban or agricultural use. Nitrogen
concentrations in rainfall can also be a consideration [5-48], Typical
values for .-nitrogen .in surface runoff as compared to domestic, wastewater
were presented in Section 3 - Waste Flow Characteristics. Typically,
approximately 60 percent of the nitrogen in raw municipal wastewaters is
in the ammonium form and 40 percent is organic nitrogen.
Within wetlands, nitrogen fixation has been shown to occur in blue-green
algae, bacteria and certain vascular plants, such as Alnus and Myrica
[5-15, 5-49, 5-52]. Bristow [5-50] determined that 10 to 20 percent of
the nitrogen assimilated by a cattail stand could be derived through
fixation. Valiela, Teal and Persson [5-51] found that nitrogen fixation
in a coastal salt marsh was decreased with the addition of ammonia.
80
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Nitrogen transformations, particularly within wetlands, are many and
varied. Factors contributing to nitrogen forms and concentrations
include concentration of inputs, immobilization, ammoni f i cation ,
nitrification, denitrification , vegetative uptake and release, and
wetland hydrology. Each of these processes are in turn affected by
environmental conditions such as substrate characteristics, pH, BOD,
dissolved oxygen (DO), temperature and bacterial action. The nitrogen
cycle is complex with many interactions as depicted in Figure 5. In
nearly all parts of the cycle, the action of specific bacteria and
microorganisms is important.
Hydrologic factors can be influential in the uptake and transformation
of various pollutants by wetland vegetation, primarily from the
standpoint of water movement and distribution. Nutrient uptake in tidal
marshes, for instance, has been found to be most effective where flood
waters flow slowly and evenly over the marsh surface [5-55]. During
high flow conditions, elevated nutrient levels in outflow waters have
been noted and attributed to leaching and flushing of decomposing plant
matter [5-47].
PROTOPLASM
, SCANTS»AM!UAI_1-.
AMIHOACIOS AND
OM6ANIC
O_tCT«IFICATIOW A MO
PMOTOCMCMICAL fttATOM
LOM TO DCCP
tCOIMCNT*
AMMONIA**"
\
OAIM FROM
VOLCANIC ACTTOH
HOCKJ
TtM
'CNIMOV
OTHCM SOUKCt*
ISUNLIOHT OR
OMOANIC HATTER)
PROTOPLASM
AMINO-ACIDS
^AMMONIA
..-NITRITE
NITRATE
.
4 TO TMt DCCOMPOSCR
OKQAHISMS
NITROGEN
GAS
Figure 5. The nitrogen biogeochemical cycle.3
a. Source: reference 5-62. ..
-------
The depth;of water within wetlands may have a pronounced effect on
uptake properties of vegetation. For example, some floating macrophytes
exhibit the highest uptake rates under shallow water conditions, whereas
many emergent species. perform best at maximum depths [5-57]. In the
study of the Wayzata Wetlafid, however, no apparent relationship between
water levels and phosphorus removal was found [5-58], Extended ponding
of water, beyond natural conditions, is likely to encourage increased
biological activity, volunteer vegetation and resultant increases in
nutrient removal effectiveness [5-59.].
The opportunity for water (and wastewater) contact with wetland
vegetation is important to biological removal processes. This is
related to detention time, flow distribution and circulation patterns
[5-47, 5-55,. 5-60]., Well-distributed flow, such as sheet flow, tends to
Increase the effective area available for biological interaction with
water-borne pollutants [5-60],
The seasons clearly are an important factor when considering natural
biological systems. With respect to nutrient retention, northern
wetlands have generally been found to act as sinks, releasing nutrients
during flushing flows in the fall, winter and spring [5-56,5-61].
Best nutrient removal efficiencies are reported in the spring and summer
growing season -[5-57].. Where winter freezing and snow conditions
prevail , the spring snow-melt period tends to be the most critical as
far as nutrient discharge is concerned [5-56, 5-61]. Freezing promotes
release of nitrogen and phosphorus from plants and soils, making them
available for subsequent washout with spring runoff [5-56, 5-61],
o Ammonificatlon
Or.ganic nitrogen is broken down,predominantly, to ammonium forms by
microorganisms in the substrate and water column of wetlands, although a
small fraction may be adsorbed by the sediments [5-49], This reaction
proceeds faster during the growing season and at higher temperatures
[5-45J. Ammonification appears to be more significant under anoxic
conditions than under aerated conditions [5-53, 5-54]. Lee et al.
[5-47] have suggested that this reaction is the most significant
rate-controlling reaction in the nitrogen cycle since their marsh
studies showed that nitrification proceeded faster than ammonification.
If low ammonium levels limit the rate of the nitrogen cycle, then
external inputs of wastewater high in ammonium should greatly affect the
cycle.
Within wetlands, plant uptake of ammonium is known to occur [5-49, 5-67,
5-68]. Although preferential use of nitrate by phytoplankton and
macrophytes. has been documented [5-69, 5-70], Patrick and Mahapatra
[5-71] and Klopatek [5-16] suggest that ammonium is the most important
form of nitrogen available to plants in waterlogged soils. This is due
to the rapid breakdown of nitrate (denitrification) under anaerobic
conditions making nitrate less available for plant roots.
82
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Fluctuations of ammonium levels appear to be related to the oxygen level
of the water column and substrate. Under aerobic conditions, aqueous
ammonium levels would be low since either conversion to nitrate
(nitrification) [5-49, 5-53, 5-69, 5-72, 5-73, 5-74, 5-76, 5-77, 5-78,
5-79, 5-80] or adsorption within organic soils [5-44, 5-76] would be
occurring. Under anoxic conditions, sediment adsorption is lessened
[5-82] and can even result in a release of ammonium and other elements
to overlying waters [5-82, 5-83]. Lee et al. [5-47] found the highest
ammonium levels in a Wisconsin marsh during the spring thaw period, when
anoxic waters and sediments were brought to the surface. It was
reported that peatlands in Michigan [5-43] and wetlands in Massachusetts
[5-85], both receiving wastewater, had highly variable ammonium levels,
with the wetland discharge concentrations at times exceeding the inputs.
This may be related to changing oxygen conditions favoring microbial
activity and ammonification.
o Nitrification
The nitrification process refers to the biological conversion
(oxidation) of ammonium compounds to the nitrite and nitrite-nitrogen
forms. The major agents are the bacteria Nitrosomonas for conversion of
ammonium to nitrite, and Nitrobacter for nitrite to nitrate, both in the
presence of oxygen. Nitri fication occurs almost entirely in the
oxidized sediment (water interface and aerated water column in wetlands)
where it is estimated that 4.6 mg/1 of DO is required to oxidize 1 mg/1
of nitrogen [5-79], Minimal nitrification occurs where the DO is less
than 1 to 2 mg/1 [5-74], although some activity has been found at DO
levels as low as 0.3 mg/1 [5-49, 5-53], Nitrification in the water
column is said to depend upon aquatic plants which provide the support
structure for slowly reproducing nitrifying bacteria [5-22].
Nitrification in the surface sediments may contribute nitrates to the
underlying anaerobic zone, where denitrification proceeds [5-77], and
has great significance in wetland nutrient cycles [5-53, 5-54, 5-74,
5-75], However, bacterial action and oxygen depletion associated with
nitrification may add to the BOD of a wetland system, thus making
wastewater BOD reduction less efficient. Other work has shown that in
some systems, warmer temperatures (above 10 °C) promote nitrification
[5-53, 5-74, 5-78] and low pH levels and high salinity inhibit this
process [5-49, 5-66, 5-78], particularly in waters below pH 5.0.
o Volatilization
Loss of ammonium in wetlands can occur through volatilization across the
air-water interface. Studies on pond systems with submerged macrophytes
and algal communities in New York [5-72] and Michigan [5-43] found that
this process could account for more ammonia removal than is achieved
through nitrification, vegetative uptake or sediment adsorption.
However, ammonia volatilization is significant only where the pH is
greater than 8,0, and may be of limited importance in wetlands and
uplands.
83
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o Denitrification
An important process for nitrogen removal is deni tn'fication, where
nitrate or nitrite-nitrogen is biochemical! ly reduced .to gaseous
nitrogen. This process occurs at the anaerobic sediment-water interface
and in anaerobic sediment layers. Typical wetland situations provide the
appropriate conditions, with-anaerobic muds, and abundant organic matter
providing energy (in the form of organic carbon) necessary for bacterial
metabolic activity. Denitrification rates have been found to decrease
with lower, temperatures and in acidic conditions [5-49, 5-53], Shallow
water depths, leading to greater mixing of the sediment-water interface
by winds and currents, may also be a factor, promoting aerobic conditions
and decreasing denitri ficat.ion [5-85],
The site hydrology, particularly of wetlands., is an important seasonal
variable affecting aeration, nutrient transport, and possibly, movement
of the nitrogen forms. Aeration at the sediment-water interface
promotes nttrification in the upper sediment layer. This creates a
concentration gradient whereby ammonium in. the lower anaerobic layer
diffuse-s into the aerated upper layer and is nitrified. The nitrate
produced during this process will either be taken up by plant roots or
diffused into the anaerobic zone where denitrification proceeds. These
processes have been shown to occur simultaneously in aquatic systems
[5-53, 5-74, 5-77.]. Denitrification can be the most significant
nitrogen removal mechanism in wetlands, where 90 to 95 percent of the
nitrate added to wetland soil-water suspensions was reduced to
nitrogenous gases in a Massachusetts wetland [5-86]. Nitrogen removal
rates of 7.4 and 3.5 kg/(ha)(d) were reported in a salt and freshwater
marsh, respectively [5-84].
Wetland, environments present ideal conditions for nitrogen sinks. The
rate of plant growth is usually faster than the rate of decomposition,
due to anaerobic s,ediment conditions favoring slow decomposition rates.
Thus, wetland soils typically contain high organic matter levels, and
fall into the peat and muck categories. Abundant organic matter and an
aerobic-anaerobic zone at the mud-water interface provide excellent
conditions for denitri fication [5-64, 5-65], The potential for nitrogen
removal is illustrated by consideration of the area of peat and muck
soils in the Sacramento-San Joaquin delta area of California. When
these soils are drained, aerobic decomposition of organic matter in the
soil above the water table is so rapid that subsidence up to 7.5 cm/yr
is observed. The organic nitrogen in the soil is mineralized and
converted to nitrate, which appears in the drained soil at high
concentrations. A subsidence of 5 cm/yr represents the release of
nitrogen in the nitrate form of about 5,050 kg/ha. Despite this
enormous input, the drainage waters and ground water in the area
maintain low concentrations of nitrate as a result of denitrification in
the saturated zone [5-87].
84
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Nitrate removal from flood-water was investigated in relatively
undisturbed cores of a fresh water swamp soil and a saltwater marsh soil
in Louisiana [5-83]. The latter was more effective in nitrogen removal ,
with an average rate of 9.2 kg/(ha)(d), while the fresh water swamp soil
removed 3.3 kg/(ha)(d). Addition of organic matter to a rice soil was
shown in other experiments to have the effect of decreasing the depth of
soil through which nitrate had to diffuse before being reduced, and
thus, drastically increasing the rate of nitrate removal.
o Uptake by Vegetation
The effect of vegetation upon nutrient cycling in wet and dryland
ecosystems is complex and varied. Interactions of the vegetative
component with the soil, water, and aerial components must also be
considered. Klopatek [5-16] suggests that aquatic vegetation functions
as a "nutrient pump," drawing in nutrients from the sediments, the
soil-water interface or from the water column, and temporarily
immobilizing these nutrients within the plant tissues. This activity
increases the nutrient adsorption,and exchange capacity in the soil and
further reduces nutrient levels in the-water.
On the other hand, nitrogen assimilated into wetland vegetation may,
eventually, be either translocated to the root components in some
species or returned to the'litter-componen.t "during senescence [5-91].
Hydrologic variables can be crucial in affecting the fate of nitrogen in
the system. Higher water levels in the fall , winter or spring can
create a flushing action leading to high discharges of particulate
matter and organic nitrogen from a system.
Tables 18 and 19 present nitrogen removal potentials for a large number
of aquatic vegetation species. The list was compiled by investigators
at the University of California at Davis [5-42, 5-93, 5-94] where
available data were converted or extrapolated to standardized units for
comparison. Table 20 presents observed nitrogen uptake rates by aquatic
plant species in terms of kg/(ha)(d), kg/(ha)(y) or kg/(ha)(mo). As
these studies were often performed for limited time periods,
extrapolation of uptake to monthly or annual rates may be unreliable.
Phosphorus Cycles in Vegetative Systems
Phosphorus is commonly reported as total phosphorus and orthophosphate
(inorganic phosphorus) forms in most studies, although more detailed
analyses may recognize four to eight forms. For the general review of
phosphorus cycles, organic and inorganic phosphorus will be the two
major forms discussed. In lacustrine systems, the inorganic phosphorus
form is most abundant in..the sediments [5-204], whereas the organic
phase is normally present in the water column [5-52]. In a
marsh-wetland system, where sediment-water interactions are
characteristic, the inorganic form will probably be more dominant.
Phosphorus relationships are generally less complex than nitrogen
85
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TABLE 18. . NITROGEN REMOVAL POTENTIAL OF EMERGENT AQUATIC VEGETATION'
Species
CATTAILS
Jjrpha spp.
T. alauca
T. latlfoUa
T. auqustifolla
T. domlnqensls
REEDS
ghrtgyttts comtunU
RUSHES
Juncus gerar dt 1
0. roemgfUnus
J. effusus
SEDGES
Care* lacustrls
C. rostrata
Removal potential (kg/ha)
Aboveground Belcnrground Total bl amass
0.76 ' - .
5.71 . '
12 207 207
220 94.50 315
509
53.40
53-310
130-330
245-467
97.8 '...;.:.'.. .':'; .,.'"-:
'J7
3.34-15.98
181-409 350-640 - ,
830
8-)l
137-409 354^640 ; , .
800
118-347
9«
680
1230
100-250
32 40 73
11 77 88
32 40 73
(continued)
Study area and reference
Poland; »ery add lake (5-98)
Poland, acid lake (5-98)
New York; winter bfomass In
wetlands (5-100) .
Wisconsin; raarsh (5-16)
Czechoslovakia; fishpond (5-125)
S. Carolina; power plant cooling
pond (5-134)
Wisconsin; marsh (5-19)
Wisconsin (5-19)
Czechoslovakia; fishpond (5-125)
S. Carolina; power plant coolinn
pond (5*134J ' J
Poland; add lake (5-98)
Poland; eu trophic lake (5-98)
Czechoslovakia; fishpond (5-99)
Delaware; salt marsh, maximum
blomass (5-105)
Poland; lake, three months bio-
mass - unrnown/mown (5-110)
Czechoslovakia; fishpond (5.125)
Ukraine; maximum productivity 1n
a eutrophlc lake (5-37)
Poland; a range of lakes (5-136)
Delaware; salt marsh, maximum
bfomass (5-105)
Maine; salt marsh, maximum
blomass (5-105).
Georgia; salt marsh, maximum
biomass (5-105)
S, Carolina; pc-wer plant cooling
pond (5-127)
New rork; wetlands (5-100)
Wisconsin; marsh (5-16)
New York; wetlands (5-100)
86
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TABLE 18. (continued)
Species
SEDGES (continued)
C. lanuqlnosa
Carex spp.
/ " '"" "
Cyperus esculentus
Sclrpus fluvlatlHs
S. valldus
S. amerlcanus
GRASSES
Phalarls arundlnacea
Removal potential (kg/ha)
Aboveground Belowground Total bloauss Slu* « «! ,.n,.,,u,
9 169 178 New York; wetlands (5-100)
Michigan; wetlands (5.134)
10-26 Connecticut; lakes (5-14)
53 154 173 Wisconsin; marsh (5-15)
128.40 s. Carolina; power plant cool-
Ing pond (5-134)
S. Carolina; power plant cool-
1ng pond (5-134)
437 Minnesota; fertilized overland
Spartlna alternlflora
26-177
11-134
18-60-
20-100
1290
980
53-112
140
270
610
How (5-109)
Delaware; marsh, maximum blomass
(5-105) .
Subtropical; marsh, maximum
blomass
90-289 N. Carol 1ns; salt marsh, various
fertilization rates (5-114)
N. Carolina; salt marsh (5-95)
Georgia; salt marsh (5-96)
Georgia; salt marsh, domestic
wastewater sludge applied (5-96)
Georgia; salt marsh (5-105)
Delaware; salt marsh (5-105)
Maine; salt marsh (5-105)
a. Source: reference 5-42.
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TABLE 19. NITROGEN REMOVAL POTENTIAL OF SUBMERGED VASCULAR PLANTS
Species
Removal potential (kg/ha)
Aboveground blonass
Total blomass
Study area and reference
'PONOWEED '
Potamoaeton spp.
P. pectlnatus
P. perfoTlatus
ELODEA
El odea canadensls
19.5
39.8
.56.50
Minnesota; agricultural drainage
ditches (5-166)
Poland; eutrophlc lake, area
highly polluted with domestic
wastewater (5-197)
Poland; eutrophlc lake, area
highly polluted with domestic
wastewater (5.197)
New Jersey; artificial ponds,
1 months growth (5-199)
New Jersey; artificial ponds,
1 months growth (5-199)
COONTAIL
Ceratophyl1um .demersum
HATEWHLFOa
Hyrlophyllum excalbescens
H. splcatum
1.34-13.1
64.94
83.9
56.28
4.47 Poland; eutrophlc lake (5-198)
Poland; small eutrophlc lake
(5-200)
89.66 Wisconsin (5-169)
8.5 Poland; small eutrophlc lake
(5-168)
Wisconsin; shallow, eutrophlc,
hardwater lake (5-182)
New Jersey; artificial ponds,
1 months growth (S-199)
Wisconsin; shallow, eutrophlc,
. ,, hardwater lake (5-202)
a. Source: reference 5-94.
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TABLE 20. NITROGEN UPTAKE RATES OF EMERGENT AQUATIC PLANTS3
Species
Uptake rates
kq/(ha)(y)
Study area and
CATTAILS
Typha latlfolla
T. august1folia
-0.9-1.6 s. Carolina; power plant
cooling pond (5-14)
1.4 Czechoslovakia; marsh growing
season (5-97)
689 Minnesota; marsh maximum
aboveground productivity (5-109)
2630 Temperate climate; total plant
mass at maximum possible
productivity (5-124)
5.9-129.8 England; marsh (5-137)
REEDS AND RUSHES
Phragmttes comnunls
270
HO
437
0.4-378
The Netherlands wastewater ponds
aboveground/
belowground plant mass .(5-12)
The Netherlands; maximum above-
ground plant mass (5-105)
England; marsh (5-137)
SEDGES
Carex lacustHs
Sdrpus amerlcanus
S. fluvlatnis
S. lacustrls
-0.32-0.34
208
260
320
New York; wetlands, growing
season (5-101)
S. Carolina; power plant cooling
pond (5-101)
Wisconsin; marsh (5-102)
The Netherlands; wastewater ponds,
aboveground/
belowground plant mass (5-12)
GRASSES
Pnalarls arundlnacaa
Spartlna alternlflora
124-272
109-299
186
Alberta, Canada; overland flow,
wastewater. (5-104)
V. Canada; overland flow, waste-
water (5-90)'
Louisiana; salt marsh (5-115)
a. Source: reference,5-42.
89
-------
because there 'are fewer chemical transformations of phosphorus in
wetl'ands or other vegetative systems. The two major processes for
phosphorus remova-1 from a system are (a) incorporation into the
sediments' and- (b) biological uptake. The phosphorus cycle is shown in
Figure 6; ..
o Sediment Interactions
A number of investigators have found that the;sediment-water interface
of aquatic systems is important in phosphorus cycles [5-49, 5-83, 5-204,
5-205, 5-206, 5-207]. In an aerated water column, inorganic phosphorus
may form complexes with various metal compounds such as oxidized forms
of.iron and manganese [5-49, 5-204, 5-206, 5-208]. These oxidized
metals effectively induce phosphorus precipitation and settling on the
bottom sediments. The aerobic upper sediment layer can function as a
"sink" for these ions. It may even, block transport of ions from deeper
sediments to the water column [5-82].
_ utotveo *^ ,
PHOSPHATES*-
FIGURE .6. Phosphorus biochemical 'cycle.3
a.-. Source: reference. 5-62.
The phosphorus sink functions only under aerobic, conditions. Where
reducing'-conditions exist in the sediment, phosphorus and other ions can
be released from as deep as 10 cm within the sediment to overlying
waters. As-mentioned before, an aerated sediment-water interface vould
form a barrier to the upward migration of phosphorus and other ions.
Some interference may occur from oxidized and reduced forms of iron
oxides in, the sediments, which have different capacities to adsorb and
release orthophosphate phosphorus, even under anaerobic conditions
[5-206]. :
90
-------
o Biological Interactions
Algae and bacteria have been identified as important components in the
phosphorus dynamics of some lakes, and may perform an important function
in marsh systems as well. Bacterial populations can transform organic
phosphorus forms to inorganic phosphorus [5-45, 5-49], and may be
associated with orthophosphorus migration to and within sediments
through microbial transport [5-49]. Additionally, some genera of
bacteria can affect the oxygen status .within the sediments, thus
promoting phosphorus transformations.
In many studies it was shown that algal uptake of phosphorus was
significant [5-47, 5-49, 5-56, 5-70, 5-74, 5-209, 5-210], and that
phosphorus was the limiting nutrient for algal growth, or limiting in
certain N:P ratios. In a University of Michigan study [5-43], high
productivity and phosphorus concentrations were.found in algae growing
near a stream of secondary-treated sewage efluent. The dynamics are not
clear, but it is possible that "luxury uptake" of phosphorus may account
for these situations. Luxury uptake of phosphorus has also been
observed in activated sludge treatment systems [5-211]. The majority of
the phosphorus taken up by the algae is temporarily immobil ized within
the algae, although small amounts are lost during active growth and
recycled to the system. Upon algal decomposition, .the organic
phosphorus is transformed by bacteria to the inorganic form where it may
again be subject to precipitation or adsorption onto the sediments,
assimilation by vascular vegetation, or may be transported from the
system.
Uptake of phosphorus by vascular plants is the last category of
biological interaction in the phosphorus cycle. Prentki [5-19] suggests
that vegetation in wetlands may act as a phosphorus "pump," taking
phosphorus up from the sediments, temporarily storing it in plant
tissue, and then returning it to the sediments through litter
decomposition. Active plant uptake of this nutrient probably increases
the total phosphorus absorbing capacity of a wetlands system, but the
ultimate phospho rus . repository . wi 11 .usually be the sediments,
reinforcing the function of sediment as a phosphorus sink. Unlike the
nitrogen cycle, where significant nitrogen loss in the form of nitrogen
gas occurs through the process ofvdenitrification, no similar process
exists for phosphorus. The only removal .mechanisms are harvesting of
aboveground plant parts and transport of phosphorus-containing organic
litter (through seasonal hydrologic flushing) out of the system. In
this respect, fluctuations in phosphorus levels follow the same pattern
as nitrogen levels, with retention during the growing season, and
release during high fall, winter or spring flows. Yearly balances in
Wisconsin studies [5-89, 5-90, 5-91, 5-92] indicated overall minimal net
phosphorus uptake by wetlands systems. Seasonal flushing of
phosphorus-containing organic litter apparently accounts for
small-to-moderate phosphorus losses, but often does not offset net uptake
by the system.
91
-------
In regions that experience warm, dry summers and moderate, wet winters,
the characteristic spring release of nutrients in wetlands may be
.attenuated or may not occur. With mild.wihters and abundant, water
supply,, some emergent and aquatic plants may continue to grow through
the winter; there will be small constant rates of.sediment accumulation
'and fl ushing ,; and i ndi sti net spring flushing trends. In fact,
significant flushing may occur with the first heavy fall/winter rains
that break the summer drought period. The dynamics of this type of
marsh system have not been thoroughly studied, and actual release rates
are unknown at this time.
o Uptake Rates by Vegetation
In general , vegetative systems are not as effective for phosphorus
removal as for nitrogen removal. Phosphorus applied to a system
eventually is bo.und to the substrate, and uplands systems which
incorporate infiltration through soil layers generally demonstrate the
greatest phosphorus removal.
Tables 21-arid 22 present phosphorus removal potentials for a large
number of aquatic vegetation species. The list was compiled by
investigators at the University of California at Davis [5-42], where
available data on studies were converted or extrapolated to standardized
units for comparison* Table 23 presents observed phosphorus uptake
rates by aquatic plant species in terms of kg/(ha)(d), kg/(ha)(y), or
kg/(ha) (mo). As these studies were often performed for, limited time
periods, extrapolation of'uptake to monthly or annual rates may be
unreliable. As statetr earlier, unless the vegetation is harvested and
removed from the s'ystem, almost all of the phosphorus applied will
-'accumulate and remain within the system, principally in the sediments,
or be flushed out [5-224].
UPTAKE AND REMOVAL OF TRACE ELEMENTS
Surface-,.ground, and domestic waters nearly all contain metals or trace
elements. Trace elements important in vegetative systems, due to their
abundance and/or potential toxicity, are copper, nickel, lead, cadmium
and zinc. Some wastewaters have high concentrations of other elements
which are usual'!'y related to a specific activity or source and must be
dealt with in a special manner.
$ome of the elements, in trace amounts, are essential plant nutrients
although the nutrient requirement and uptake ability vary with different
plant species. For example, many soils are low in zinc and enrichment
with zinc-laden wastewater can promote plant growth. However, when
applied in excess, trace nutrienta can accumulate and pose potential
long-term hazards to plant growth and secondary consumers. Copper,
zinc, nickel and cadmium are metals that can accumulate in soils and
lead to phytotoxicity (damage to plants). Cadmium, and to a lesser
92
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TABLE 21. PHOSPHORUS REMOVAL POTENTIAL OF EMERGENT AQUATIC VEGETATION3
Removal potential (kg/ha)
Aboveground
CATTAILS
Typha spp. 0.419-0.481
T. august 1foH a
7.9
5.0
4.0
6-10
31.7
45-65
32-46
T. olauca 2.7
T. Iat1fol1a 43.9: ,.'
77
6.8-32
24
43
REEDS
Phragmltes tomiunls 0.126
0.39-1.16
32-53
0.4
14.63.5
62.7
14-53
80
10.6-26.7
RUSHES
Juncus effusus
SEDGES
Care* spp. 0.96-3.48
Care* lacustrls 5
2.4
Belowground Total blomass
Poland; add lakes (5-98)
Wisconsin wastewater pond, seasonal
totals of biweekly/
monthly/
seasonal harvesting schemes(5-39)
Wisconsin-, wastewater pond,
multiple harvests (5-90)
H. Europe; wastewater pond (5-36)
Czechoslovakia; f1shpond( 5-125)
Wisconsin; wetlands! 5-19)
39 42 New York; wetlands, winter
blomass (5-100)
. 28.6 .42.5 Wisconsin, marsh (5-16)
Czechoslovakia; fishpond (5-125)
Wisconsin; wetlands (5-19)
Wisconsin; wetlands, winter/
sunner plant mass (5-19)
Poland; acid lake (5-98)
Poland; eutrophlc lakes (5-98)
38-74 Czechoslovakia; fishpond (5-99)
Poland; lake, 3 month growing
season (5-110)
Sweden; lake (5-111)
N. Europe; wastewater pond (5-36)
38-74 Czechoslovakia; fishpond (5-125)
N. Europe; marshes, maximum
product 1v1ty< 5-37)
Poland; marsh (5-136)
10-30 S. Carolina; power plant cooling
- pond ( 5-127)
Michigan^ wetlands ( 5-34)
5.5 11 New Tork; wetlands (5-100)
19.7 22 Wisconsin; wetlands §-16)
(continued)
93
-------
TABLE-21. (Continued)
Species
SEDGES (continued)
C. rostrata
C. lanqulnosa
C. strlfta.
Sdrpus fluvlatllls
Removal
Abonground
S
1.2
20
11.3
potential (kg/ha).
Belowground Total
5.5
37
32
btomass
11
38
59.3
34
New York; wetlands (5-100)
New York; wetlands(S-lOO)
N. Europe; wastewater pond
Wisconsin; iursh{5-16)
U1scons1n;wastewater pond.
(5-36)
total
GRASSES
Phalarts irundlhacea
Spartlna alternlflora
35.1-38.3
43.71
33-56 ;
6
1.1-14.9
of 4 harvests(S-89, 5-90)
Wisconsin; vastewater pond, total
of 4 harvests (5-89, 5-90)
67.2 N. Europe; wastewater pond
(5-126)
Minnesota; marsh maxlnura
production ( 5-109)
Pennsylvania; overland flow, waste-
water, totals of 3 harvests/season
CM 15)
Georgia; salt marsh (5-131)
N. Carolina; salt marsh (5-95)
a. Source: reference..5-42.
94
-------
TABLE 22. PHOSPHORUS REMOVAL POTENTIAL OF SUBMERGED VASCULAR PLANTS'
Species
PONDWEED
Potarooqeton spp.
P. natans
P. pectlnatus
Removal potential (kg/ha)
Aboveground blomass Total blomass
12.9
3.6-11.6
0.6
Study area and reference
Minnesota; agricultural drain-
age d1tch(5-!66)
Sweden; small stream polluted '
1th domestic wastewater (5-170)
Poland; lake, site heavily
P. perfollatus
0.6
3.5
polluted with domestic waste-
ater(5-197)
Poland; lake, site heavily
polluted with domestic wasti-
water(5-197)
New Jersey; artificial ponds,
1 months growth (5-199)
ELODEA
Elodea canadensls
12.1
0.03-0.93 Poland; eutropMc lake(5-168)
New Jersey; artificial ponds,
1 months growth (5-199)
COONTAIL
Ceratophyllum demersum
0.62-6.08
0.58-0.99 Poland; eutrophtc lake (5-168)
Poland; eutrophtc lake (5-200)
WATERmiFOIL
Hyrlophyllun excalbescens
M. splcatum
12.55
8.97 Wisconsin (5-169)
0.015-0.078 Poland; eutropMc lake(5-168)
Wisconsin; shallow, eutropMc,
hardwater lake(5-171)
2.90-17.70
2.20-12.30
20.3
1.13-5.06
12.99
Wisconsin; lake(5-198)
S. Carolina; power plant
cooling pond (5 -198)
New Jersey; artificial ponds,
1 months growth (5-199)
Wisconsin; highly alkaline
lake(5-201)
Wisconsin; shallow, eutrophlc,
hardwater lake(5-202)
a. Source: reference 5-94.
95
-------
TABLE'23. PHOSPHORUS UPTAKE RATES OF EMERGENT AQUATIC PLANTS6
Species
Uptake rates
kg/(ha)(d(- kg/(ha)(y)
Study area and reference
CATTAILS
Typha auqust.i folia
T. latifolia
0.7-32.1 Temperate marsh (5-137)
-0.03-0.19 S. Carolina; power plant cooling
pond (5-13)
0.08 Czechoslovakia; marsh, growing
season (5-97)
0.95 31 Wisconsin; marsh, growing season
total blomass (5-19)
74 Minnesota; maximum productivity
(5-109)
403 Temperate climate; maximum pro-
ductivity, total biomass (5-124)
REEDS AND RUSHES
Phragmites communls
35
20
0.13-19.6
Temperate climate; wastewater
ponds aboyeground/
belowgrbund (5-12)
England; marsh (5-137)
SEDGES
Carex lacustrls
Scirpus amer.lcanus
S. lacustrls-
S.-:fluv1at.11is .
0.06
-0.04-0.05-
50
55-
53.3
New York; wetlands, growing
season (5-101)
S. Carolina; power plant cooling
pond (5-13)
The Netherlands ; wastewater ponds
aboveground/
belowground ( 5-12) .
Wisconsin; marsh (5-.16)
BRASSES
Ph41 ar1 s arundlnacea.-.
'Spartina aTternlflora:
0.06 .
70.14
Temperate climate; wastewater
Irrigation (5-116)
Georgia; salt marsh (5-131)
a.Sources reference '5-42'.
96
-------
extent copper, can become hazards at high concentrations to secondary
consumers of plants enriched with these elements.
Physical and chemical interactions that can remove trace elements from
waters were discussed in Section 4. In most vegetative systems, the
physiochemical interactions of pollutants and sediments are the primary
removal mechanisms. Biochemical interactions are secondary mechanisms
for incorporation of trace elements into a system, and can provide
additional capacity for pollutant removal in a system [5-113, 5-164].
Further, since increasing the organic content of sediment improves its
storage capacity of heavy metals, the natural replenishment of organic
material in a wetland aids the physiochemical process [5-224],
Emergent Aquatic Vegetation
Heavy metals are adsorbed by aquatic vegetation primarily via the roots
from the sediment, although leaf absorption of heavy metals from waters
also occurs to a lesser extent. As discussed under physical and
chemical sediment interactions, pollutant concentrations are usually
highest in the upper sediment layers, specifically.the 'top few
centimeters. Therefore, rooted emergent vegetation, particularly
shallow-rooted species and types with creeping rhizomes near the
sediment surface, is especially susceptible to heavy metal uptake.
Tables 24 and 25 present heavy metal removal potentials for several
types of emergent aquatic vegetation, based on research where uptake
was reported in terms of specific volume or area. Characteristics of
several vegetation types are discussed below.
o Cattails
Maximum uptake of heavy metals in aboveground tissues occurs during the
growing season, prior to the production of peak aboveground biomass.
During the dormant season, heavy metals are not translocated back to the
rhizomes, but remain in the stem and leaf parts. Cattails, particularly
Typhus latifolia, may be useful in removing copper and moderate amounts
of manganese, and zinc, as .shown in Tables 24 and 25. The iron uptake
rate in terms of total plant mass has been measured at 23 kg/(ha)(y),
assuming maximum production [5-124],
o Reeds and Rushes
The available literature reports removal rates for reeds only. The
common reed Phragmites communis exhibits a seasonal uptake and storage
pattern, where metals are taken up during the spring and summer, with
the peak uptake occuring in late summer. By the fall, the seeds show
concentrations two to four times greater than the leaves and stems. In
one case, the copper concentration in the seeds was found to be 30 times
greater than in leaf tissue. During the fall, metal uptake levels off
and decreases through the winter, with a concomitant rise in
97
-------
TABLE 24. HEAV'Y 'METAL REMOVAL POTENTIALS OF'-EMERGENT AQUATIC PLANTS
(Cd, Co, Cu, Fe, Hg)a
Species Cd
CATTAILS
Typha augustifoHa .
T. latlfolla
REEDS AND RUSHES
Phraqrcltes comrounts
SEDGES
Garex stricta
Sclrpus lacustris
BRASSES
Phararls arundlnacea 0.001-0.005
Spartina alternl flora
0.004
S. alternl flora :and 0.0003-8.0050
S.patens
OTHERS
Justica amertcana
Sallcornia pacifica 0.08-0.38
Removal potential (kg/ha)
Co Cu Fe Hg
0.006 0.068 15.80 W. Europe; wastewater
ponds (5-36)
0.010 0.360 Ukraine; reservoir (5-126)
0.028 0.188 41.20 W. Europe; wastewater
ponds (5-36)
0.004 0.350 Ukraine; reservo1r( 5-126)
0.020 0.152 103.40 W. Europe; wstewater
pond (5-36)
a023 0.161 26.20 U. Europe; wastewater
pond (5-36)
Pennsylvania; overland
wastewater disposal ;
varied rates (5-22)
0.19-9.90 N. Carolina; salt narsh(5-99)
3.84 H. Carolina; salt marsh(5-133)
0.026 5.25 0.001 S. Carolina; salt marsh(5-28)
Massachusetts; salt marsh,
wastewater sludge applied
at various rates to a
mixed stand (5-10, 5-26)
0.30-0.80 9.8-38 Alabama; lake (5-135)
0.42-1.58 California; brackish marsh
receiving urban runoff
.-.- (5-41)
a. Source: references 5-41, 5-42.
98
-------
TABLE 25. HEAVY METAL
(Mru Mo, Ml,
REMOVAL POTENTIALS OF EMERGENT AQUATIC PLANTS
Pb, Zn)a
Species
CATTAILS.
Typha august 1 fol 1 a
T. latlfolia
REEDS AND RUSHES
Phraqnltes conuunls
SEDGES
Carex stHcta
Sdrpus lacustrls
GRASSES
PhalaMs arundinacea
Spartlna «1 tern! flora
S. alterni flora
S. alterni flora
S. patens
OTHERS
Justlda anerlcana
Sallcornla padflca
Removal potential (kg/ha)
Kn Ho N1 Pb Zn
11.22 0.004 0.027 0.629
13.66 0.600
7.44 0.012 0.068 1.653
15.60 0.068 0.500
t
26.38 0.008 0.067 1.714
40.32 0.018 0.058 1.680
0.106-0.437
0.02-0.42
0.028-0.116
0.32 0.06
0.35
0.048-0.301
1.3-2.5 2.6-5.8
0.026-1.01 0.43-0.68
Study area and reference
W. Europe; wastewater
ponds (5-36)
Ukraine; reservoir (5-126)
W. Europe; wastewater
pond (5-36)
Ukraine; reservoir (5-126)
W. Europe; wastewater
pond (5-36)
W. Europe, wastewater
pond (5-36)
Pennsylvania; overland
wastewater disposal ;
varied rates (5-22)
N. Carolina; salt marsh(5-99)
Massachusetts; salt marsh,
wastewater sludge applied
at various rates (5-129)
K. Carolina; salt marsh(5-133)
S. Carolina; salt marsh(5-28)
Massachusetts; salt marsh.
wastewater sludge applied
to a mixed stand at
various rates (5-10, 5-26)
Alabama; lake (5-135)
California; brackish marsh
receiving urban runoff
(5-41)
». Source: references 5-45, 5-42.
99
-------
concentration in underground parts. By late winter, metal accumulation
is entirely within the underground parts with 2 to. 10 percent appearing
in the shoots [5-2.4]. Except for the late fall and winter when reed
metabolism appears to be geared toward seed production, root
concentrations are always greater than leaf or stem concentrations.
Reeds may be useful in removing significant amounts of copper and iron
[5-24, 5-36,. 5-126] and moderate amounts of cobalt and molybdenum
[5-36].
o Sedges
In[ laboratory studies, mercury uptake by a bulrush, Scirpus cyperinus
was primarily-through surface adsorption by submerged shoots instead of
uptake by roots from sediment's. Mercury-adsorption'through the exposed
tissues increased with increasing aqueous mercuric chloride
concentrations [5-128], S. lacustris showed svgnfficant removal
potentials for zinc (.058 kg/ha) in a. wastewater pond [5-36].. Also in a
wastewater pond, Carex stricta has high removal potentials for iron
(103.4 kg/ha), nickel (0.67 kg/ha), and, manganese ,(26;38 kg/ha), [5-36].
o Grasses
Reed canarygrass (Pha-laris arundinacea) accumulates metals in proportion
to soil and water concentrations [5-22, 5-23].- Lead translocated from
roots, to aboveground parts does, not return to the roots during the
wi.nter [£.-23]. Assuming, that this is true for other metals, then
pollutant-removal from-the system would occur only through external
harvesting.. The, remo.va.l potential of reed canarygrass ranges from 0.001
kg/ha* (cadmium) to 0.69 kg/ha (copper).
Co'rdgrass (Spa-rti na spp.) is similar to canarygrass in that
t ran si o cation of accumulated heavy metals to belowground parts does not
occur during; leaf senescence. However, the- role, of'cord grass in an
estuarine'-saitr marsh ecosystem leads to other interactions that are more
important in heavy, metals removal. Undecomposed cordgrass litter above
the sediment Ta-yer absorbs metals directly from the water, while
decomposing litter releases humic. acids, which act as metal chelators.
Thus, the cordgra-s;s lifter compartment can' actually accumulate more
heavy metals than the 1iving plant mass and act as.a sink for heavy
metals. The living eordgrass system, in comparison to other freshwater
emergent vegetation, generally sho.ws lower heavy metals removal
potential's.-, as shown* in Tables 24 and 25.
Anaerobic conditions in a salt marsh, where mercury has accumulated in
the sediments as insoluble sulfides, can lead: to the production .of toxic
methyl mercury through bacterial methy.Tation. Whereas mercury would
normally be absorbed by roots from the sediments, methyl mercury can be
absorbed by leaf and stem tissue too, accumulating tissue concentrations
higher than concentrations in the surrounding soil [5-29, 5-130],
100
-------
o Other Types
In the water willow (Justicia americana), maximum uptake of heavy metals
in aboveground tissues occurs prior to the production of peak
aboveground biomass. Little is known about the dormancy pattern. J.
americana has significant removal potentials for zinc (2.6 to STS
kg/ha), manganese (1.3 to 2.5 kg/ha) and copper (0.30 to 0.80 kg/ha)
[5-135].
The perennial pickleweed (Salicornia pacifica) has significant removal
potentials for cadmium (0.016 to 0.024 kg/ha) [5-41]. Uptake probably
occurs from the soil to the roots and aboveground parts, although direct
absorption through stem/leaf tissue can also occur. Data are scarce on
the overwintering patterns and heavy metals cycling through the system.
Floating Aquatic Vegetation
Root characteristics are probably most important in determining the
heavy metal removal potential of floating vegetation. Roots .may be
simple and sparse as in duckweed or fibrous and matted as in water
hyacinth. Another consideration is water depth and root length. Where
roots are able to extend and grow in sediment, the removal potentials
may vary. Sediment-rooted submerged vegetation generally absorbs fewer
minerals from the water than those rooted in a nonsoil medium or with
entirely aquatic roots [5-22.]. This may be the case in floating
vegetation as well.
o Water Hyacinth
The intricate root system of water hyacinth mats has a strong affinity
for suspended particulates. Heavy metals associated with particulate
matter are probably removed through the root filtering mechanism.
Measurements have been made of decreases in pollutant concentrations
accompanying hyacinth growth [5-123] and of various metals recovered in
hyacinth plants [5-138, 5-141, 5-150, 5-152, 5-155, 5-156, 5-158]. The
highest metal concentrations occur in the roots [5-148,. 5-150, 5^158]
with some translocation to upper plant parts [5-150, 5-152, 5-155,
5-158], However, the significance of heavy metal removal through
physical and chemical processes associated with the roots, as. compared
to biological uptake, has not been determined. Water hyacinth may be
useful in removing iron, mercury, arsenic, chromium, copper, lead and
nickel where biomagnification factors of plant tissue accumulations can
be 50 to 200 times the water concentration. For iron and mercury, the
biomagnification factor can rise to 6,600 times and almost 700 times,
respectively. Concentrations of heavy metals in water hyacinth reported
in experimental studies are given in Table 26.
o Duckweed
The high productivity of duckweed can lead to active uptake and
accumulation of trace metals beyond ambient water concentrations [5-139,
101
-------
TABLE 26. HEAVY METAL CONTENT OF FLOATING AQUATIC VEGETATION"
"Dry weight, ag/g
Species
Al
Cd
Cf
Co
Cu
Fe
Pta
Hg
Nt
Ag
Sr
Zn
Comments and reference
Water hyacinth
O
ro
300
3200
200-670
4.001
0.5-Z.9 0.4-2.6 15-70
<0.007 <0.01
89-568
0.063 <0.001
2-164 4-286
tO. 2-281
15-570
25-257
300-500
<0.05 <0.02 £0.01
140-650 102-544
4-77
96 hrs. tn 0.1 ppm Cd and
10 ppm Pb solutions
(6-138)
Plants of different sizes
from natural populations
(5-151)
24 hrs. In 0.6-2 ppm solu-
tions (5.153)
0.58 2 uks. tn sewage effluent;
measurements made on roots
only (5-154)
24 hrs. tn 0.6-2.4 ppm sol-
utions. Uptake measured
as difference tn metal con-
tent of substrate (5-155)
6 wks. tn chemical waste
system. Lowest concen-
trations In leaves
and stems; highest tn
roots (5-157)
24 hrs. tn 0.001-0.1 ppm
solutions. Lowest con-
centrations In. plant tops;
highest In roots (5-158)
Duckweed
3-1.101-
468 17.4 65 19.2 101.1 13.9
5.6
1980
26 79
1840
Naturally-occurring pop-
ulation, England
(5-159)
679 . 58 Plants growing tn drain-
age System of coal -fueled
power plant, S. Carolina
(5-162)
American River, California
(5-163)
«. Source: reference 5-93.
-------
5-160, 5-163, 5-165]. In Spirodela polyrhiza, removal potentials for
manganese and cobalt were greater than those of other emergent or
floating aquatic vegetation [5-164], Field studies on Lemna minor
revealed biomagnification factors of 20,000 to 100,000 times ambient
water concentrations for cobalt, copper, nickel and titanium; and
300,000 to 660,000 times ambient water concentrations for iron,
manganese and aluminum [5-163]. Since duckweed normally grows without
sediment contact, uptake must be directly from the water. It is
possible that the continual decay process, associated with plants that
have high productivity, releases these trace elements continuously to
the upper waste layers, so that they are recycled to new plant growth
[5-163], Concentrations of heavy metals in duckweed, from experimental
studies, are given in Table 26.
-»
Submerged Aquatic Vegetation
Submerged vascular plants cycle trace elements in a similar manner to
emergent vegetation. Heavy metals are absorbed through the roots from
the sediments, and are subsequently translocated to other plant parts.
As the plant dies and decomposes, plant elements are recycled back to
the water. Submerged plants are generally shallow-rooted, and are thus
exposed to the higher concentrations of heavy metals that settle out
within.the upper sediment layer [5-196].
Submerged plants are generally found in alkaline, hard waters (pH 7 to
10) where they have the ability to utilize bicarbonate as a carbon
source when the high pH decreases the amount of free carbon in the
water. Carbonate deposition on plant leaves and stems is a side effect
of bicarbonate or carbon dioxide absorption by submerged plants in
alkal ine calcareous waters. Marl, as these deposits are called, is
formed by excess bicarbonate within the plant reacting with hydroxyl
ions at the leaf surfaces, and precipitating with calcium onto plant
surfaces. Marl deposit formation can be an important mechanism for
capturing potentially hazardous ions that coprecipitate with calcium,
such as strontium.
A comparison of heavy metal removal potentials of several types of
submerged vegetation is presented in Table 27. Generally, submerged
plants have a lower plant mass than emergent or floating vegetation, and
thus, lower removal potentials for heavy metals. This becomes apparent
when comparing data on submerged plants with the reported data on other
vegetation types. However, the removal potentials of pondweeds for
cobalt and copper can equal the potentials for reeds and cattails.
Several submerged plant species also exhibit tolerances for specific
metals as discussed below.
o Rondweed
Potamogeton sp. tend to concentrate heavy metals in the roots and
rhizomes, where the primary contact occurs. Zinc, however, accumulates
in the stems and leaves [5-178], P. pectinatus readily translocates
103
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TABLE 27. HEAVY METAL REMOVAL POTENTIALS OF SUBMERGED VASCULAR PLANTSa
Species
PONDWEED
Potamoqeton crlspus
P. lucens
P. pectlnatus
Remova) potential (kg/ha)
Al
Cd
Co Cu Fe ' Mn
Zn
P. perfollatus
MATERHILF01L
Hyrlophylluro splcatum 0.109
0.001-0.114
0.024 0.087 4.250 0.400
0.010 0.030 2.500 0.210
0.140 0.040 0.001
0.140 0.040 0.001
0.007 0.130 0.109 0.002
Comments and reference
Indiana; shallow eutrophlc lake;
soil Cd concentrations 0.66-
44.8 ppm (5-175)
Ukraine; shallow eutrophlc
reservoir. (5-126)
Ukraine; shallow eutrophlc
reservoir. (5-126)
Poland; eutrophlc lake, site
heavily polluted with
domestic wastewater, reduced
growth. (5-197)
Poland; eutrophlc lake, site
heavily polluted with
domestic wastewater reduced
growth. (5-197)
Wisconsin; shallow eutrophlc
hardwater lake. (5-171)
a. Source: reference 5-94.
-------
lead from roots to shoots, where it accumulates without adverse effects
[5-181]. Incorporation of lead into the cell walls apparently changes
it into a form that is nontoxic to the plant [5-179]. In another study,
P. c r i s p u s growing in a river delta was found to have higher
concentrations of copper, manganese and chromium than the common reed
(Phragmites communis), although levels in Elodea were even higher
[5-24j.
Several studies have been done on strontium and calcium uptake in
pondweeds. The two elements are interchangeable in plant metabolism,
although the affinity for calcium is greater in most plants [5-176,
5-177] Strontium, however, can be incorporated with calcium into the
carbonate or marl deposits as the plant rids its system of excess
carbonate. By this mechanism, strontium-90, an environmentally
hazardous radionuclide, can be sequestered into a sparingly soluble
plant deposit [5-186].
o Elodea
Elodea is a rapid-growing submerged plant that can grow rooted in
sediment, or become fragmented and free-growing in water. Heavy metals
can be absorbed read.i.ly through both roots and shoots, with
sediment-rooted plants concentrating elements in the roots. Heavy metal
contents of plants are proportional to environmental concentrations
[5-24, 5-183, 5-185, 5-187, 5-188]. Elodea can cycle elements rapidly
through an aquatic system, taking up heavy metals from soil and water,
retaining a portion within the plant, and releasing 60 to 70 percent of
the initial amount absorbed, back into the water [5-183, 5-184, 5-185,
5-186, 5-187, 5-188].
Elodea can take up mercury in direct proportion to water concentrations
at rates of 1 to 33 mg/(g dry wt)(d), accumulating up to 1,000 mg/g dry
wt in laboratory studies [5-189],
Inorganic mercury and organic mercury (in the form of methyl mercury)
are taken up without specific preference. In a study on Elodea densa,
plants growing in an inert nonsoil medium (glass beads) accumulated
significantly more mercury (up to 32 percent) than those rooted in soil.
The soil apparently contributed enough plant nutrients so that mineral
uptake (including mercury) from the water was reduced. Soil in which
Elodea had grown was also found to accumulate about twice as much
mercury as plant-free soil due possibly to: (a) increased surface area
of soil from disturbance by plant roots leading to increased
sediment-mercury interactions; or (b) deposition of mercury-containing
suspended material, algae and dead leaves on the soil surface [5-189].
Although removal potentials of Elodea have not been documented in terms
of kg/ha, various studies have shown that Elodea can be more effective
than other submerged plants and more effective than emergents, such as
the common reed, in removing copper, manganese and chromium from water
[5-182, 5-189, 5-190].
105
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o Goontafl
Ceratophyllum sp. absorbs heavy metals primarily through the foliage, as
opposed to roots in the sediment [5-191], Under experimental
conditions, uptake is highest during rapid growth periods, reaching a
maximum -at 6 to 9 weeks and decreasing by the twelfth week [5-193], In
laboratory^studies, Cera to phy Hum demersum absorbs both ethyl mercury
and methyl mercury and is able to convert both into inorganic mercury
[5-192].
o Water-milfoil
Absorption of heavy metals through the foliage or roots of watermilfoil
has not'-been verified. As the plants are relatively fragile and
reproduce mainly by fragmentation, as do Elodea and coontail, they
probably exhibit rapid seasonal growth and uptake of nutrients and trace
elements through the foliage. Limited data are available on heavy metal
uptake rates .by watermilfo il. In field studies.comparing pollutant
concentrations in watermilfoil to concentrations-in the emergent plants
Glycera .sp. and Chara sp., watermilfoil had higher-accumulations [5-194,
5-195, 5-196]. However, the overall removal is probably lower than
removals by the emergent cattails and reeds. .
UPTAKE AND REMOVAL OF OTHER POLLUTANTS
Other pollutants of environmental concern that may be present in
waistewaters include the trace element boron, and organic compounds such
as petroleum products and pesticides. The ability to accumulate these
pollutants has been studied for a few plant species only and the data
are generally insufficient to make comparisons of removal effectiveness
between vegetation types.
Bofon Uptake
Bo'ron is absorbed in pi ant systems by the same-meehanisms discussed for
heavy, metals .Primary uptake occurs through the roots, and accumulation
in abovegrpund parts reaches'a. peak; when maximum plant biomass is
attained. Grasses (monocotyledons) have a lower boron requirement than
dicotyledons, and probably have lower removal potentials for boron.
o Emergent Aquatic Plants
The boron removal potentials for emergent plants are all based on
studies of wastewater or cooling ponds in temperate climates. Cattails
and reeds.have similar removal potentials of 0.030 to 0.352 kg/ha
[5-117, 5-118] and 0.37 kg/ha [5-36], respectively. Bulrushes range
from 0.011 kg/ha in a South Carolina cooling pond [5-117] to 0.496 kg/ha
in- a. wastewater pond [5-118], Carex stricta exhibited the highest
removal potential among emergent plants of 0.582 kg/ha [5-36]. Boron
removal potentials of 0.007 to 0.029 kg/ha were also found in various
species of water lilies [5-119].
106
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o Floating Aquatic Plants
Boron uptake has been studied in only one floating plant, Lemna minor
(duckweed). Calculated uptake rates for boron in experimental aqueous
concentrations of 0.01 to 1.01 mg/1 ranged from 159 to 160 mg/(g
ash-free dry wt)(wk). Boron concentrations in Lemna were 4 to 70 times
greater than concentrations in other submerged aquatic plants collected
from the same wastewater ponds [5-149],
o Submerged Aquatic Plants
Few submerged plants have been studied for boron removal potential. The
highest reported potential is 0.11 to 0.23 kg/ha for a community of
pondweed, elodea and coontail , harvested from a Michigan wastewater pond
[5-167]. Generally, submerged plants appear to have a lower boron
removal potential than emergent or floating plants. Potamageton
diversifolius, growing in boron-containing waters of 0.1 to 5.2 ppb,
showed a concentration factor of 10 to1 50 times in the. pi ant tissues
[5-117]. Boron removal potentials of 0.007 to 0.083 kg/ha during the
growing season, have been .reported; for coontail (Ceratophyll-um demersum)
[5-172]. Myriophyllum heterophyllum is reported to be able to attain
boron concentrations 21 to 100 times natural water levels [5-117]. A
removal potential of .007 kg/ha was reported for Myriophyl lum spicatum
in a Wisconsin Lake [5-171]. '.
Organic Compounds
The organic matter represented by BOD in municipal wastewater effluent
and stormwater will, initially, be removed by sedimentation or stay in
solution or colloidal suspension in a wetland. The settled organic
material will be microbially digested in the bottom sediment. High
organic loads to the wetland may induce anaerobic conditions in what
might otherwise be aerobic sediments.
The soluble and colloidal organic matter will be metabolized by
microorganisms attached to plant roots and stems, and to a much lesser
extent, by free floating microorganisms in the water column.
Organic-nitrogen derived from metabolic wastes and dead organisms is
converted to elemental nitrogen (or mineralized) by microorganisms in
soils and waters. Many synthetic organic chemicals are also broken down.
by microorganisms. The mineralization process frees carbon and releases
energy for microbial biosynthesis. Detoxification is a common result of
mineralization [5-88, 5-102].
A microbial conversion different from mineralization can also take
place. Compounds are acted upon biologically in soils and waters, but
not all of the products resulting can be used as nutrient or energy
sources. The microbes will utilize those products compatible with
energy and nutrient needs, while the unusable by-products gradually
107
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accumulate [5-173* .5-174], The products are generally nontoxic or of
low .toxieity, although they may be subject to biomagnification through
plant uptake and the food chain. Some products may be toxic only to
specific organisms. In rare but significant instances, the products can
be highly toxic, such as methyl mercury produced from the methylation of
mercury by bacteria.
Organic material in a wetland discharge, will typically consist of
[5-224]: .
o extpacellular organic compounds leached during the growing
season;
o organic compounds leached from decaying vegetation;
o algae and microbes suspended in the water column;
o biorefractory organics in the influent.
Petroleum'products, ,phenols and. phenol derivatives.-have been studied in
conjunction with oil spills and urban runoff Centering., vegetati ve
systems. Other organic compounds that: have-'been studi-ed on an
intermittent basis include growth substances, herbicides and
insecticides. Uptake of organic compounds by submerged plants has not
been studied [5-42].
o Emergent Aquatic Plants
Petroleum products are not actively taken up by emergent plants.
Incidences of oil spills which spread to wetland areas generally did not
cause noticeable damage to the vegetation. However, the emergent
vegetation is able ,to act as a biological filter, promoting the proper
conditions for breakdown of hydrocarbons, while the hydrocarbons are
actually.decomposed (oxidized) by bacteria [5-103, 5-108, 5-112, 5-118,
5*;132, 5-180, 5-203]. Plant stems and leaves provide b:acterial
attachment, sites, and thus, increased, contact/treatment areas for
hydrocarbons. The presence of cattails and bulrushes has been reported
to increase the hydrocarbon.decomposition rate-to as much as 7 timesrthe
rate measured -inthe absence of emergent vegetation. [5-120, 5-121].
While reeds, rushes arid grasses have not been studied, a similar
bacterial mec.han-ism may also be operative. In European wastewater
treatment po.nds.j phenol, uptake rates by .bulrushes is 4 mg/(100 g
plant)(d). Phenol derivatives included, p-creso.l, xylene, pyrocatechol ,
resorcino'l,, pyrogajlol, pyr.jdine and hydroquino-ne [5^121].
o Floating Aquatic Plants
Reduction of phenol concentration in solution from 25 to 100 mg/1 to
less than 0.5 mg/1 in 72 hours appeared to be related to the presence of
water hyacinth [5-143]. However, phenol was not recovered in the plant
tissue and. the phenol removal or breakdown mechanism is uncertain. In
another study, water hyacinth absorbed 1.30 to 2.5 mg toxaphene/plant
from a 2 mg/1 solution. Toxaphene, an organic insecticide, appeared to
be taken up most rapidly in the first 48 hours [5-142],
108
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The uptake and accumulation of growth substances such as
2, 3,5-trichlorobenzoic acid (TBA), indoleacetic acid (IAA),
phenoxyacetic acid and hexose have been studied for two species of
duckweed: Lemna mi no r and Lemna gi bba [5-144, 5-145, 5-146],
Temperature, pH, growth substance concentration, light;and presence of
chlorine affect the accumulation rates in different plant parts [5-140,
5_144, 5-146].
Uptake of Biocides
Insecticides and herbicides are applied to aquatic systems to reduce
insect vectors and nuisance plants and algae. Accumulation of these
biocides in plant tissue affects considerations for the ultimate use or
disposal of plant material. This can be important in the food chain
where secondary consumers can concentrate these biocides and experience
toxic effects. In addition to physical and chemical removal of the
biocides, the plants and highly varied microbial populations of a
wetland will metabolize many organic biocides.
o Emergent Aquatic Plants
Biocide uptake has been studied in water lilies and jointgrass. The
pesticides hexachlorocyc.lohexane (HCCH) and DDT accumulated 10 to 12
times ambient water levels in the water lily Nymphaea alba [5-122], The
insecticide mevinphos was absorbed at the rate of 7 ppm/d by Nymphaea
odorata and Paspalum distichum (jointgrass) [5-123], The submerged rush
Juncus repens had no effect on mevinphos removal.
o Floating Aquatic Plants
Water hyacinth can achieve rapid removal of diphenamid, a weed control
agent, through degradation and release of metabolics back into the water
[5-147]. Applications of the herbicide copper sulfate pentahydrate over
2 mg/1 inhibited water hyacinth growth and led to increased copper
concentrations in the roots [5-148].
o Submerged Aquatic Plants
At low biocide concentrations in the aquatic medium, submerged plants
appear to be able to accumulate and metabolize biocides without showing
toxic effects. Uptake of organo-chlorine insecticides is dependent upon
plant lipid content and contact surface area available for absorption.
Submerged plants, such as pqndweed allow contact with the entire plant
surface. Potamogeton pectinatus accumulated DDT and HCCH at average
levels of 3.80 and 0.94 mg/kg dry wt [5-212]. DDT uptake comparisons
have also been performed on different pondweed species [5-213].
Removal of the pesticide pollutants dichlobenil , diphenamid and amitrole
were measured on Elodea canadensis, Potamogeton diversi folius and
Myriophyllum spicatum. All plants were affected by dichlobenil
109
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concentrations of 0.17 mg/1 and took up small amounts of diphenamid.
Only Elodea accumulated amitrole [5-217]. Myn'ophyllum brasiliense can
degrade diphenamid to a relatively nontoxic monomethyl derivative
[5-214]. M. .brasiliense also absorbs the herbicide simazine through the
roots [5-2T5-~H!
Bacteria and^Viruses
Little infbrma-tion is available on the removal of pathogens in wetland
systems. Bacteria and viruses are subject to sedimentation, exposure to
ultraviolet radiation, and attack by chemicals. Additionally, natural
predation by other organisms will occur in a wetland. Pathogens which
rely on a specific host may also die off. However, reduction rates and
the safety, from transmission of diseases to either humans, animals or
even plants have not been established.
Other Water Quality Parameters
Within the water column, variations in pH, salinity or electrical
conductivity, dissolved oxygen and water color are most evident under
different wetland conditions.
o pH Levels ^
Factors that have been observed to influence pH levels in wetlands water
quality are (a) the nature and source of wetland inflow [5-216], and (b)
high photosynthetic activity within the wetland [5-47].
Typical surface wate-FS entering wetlands exhibit neutral pH values
b.etween 6.5 arid 7.8; Variations in pH occur where upstream sources may
include acid mine drainage, municipal, commercial or industrial
discharges,, and specific geologic or mineralogic soils*
In Verry's^ study of Minnesota perched (ombrotrophic) and ground-water
(minerotropnic). wetlands [5-216], striking differences were found in pH.
The perched bogsj with no ground-water inflow, had pH values, of 3.1 to
4.2, totally independent of streamflow. The s:uspect;ed sources'of
hydrogen ions were (a) dissociation of sulfuric acid derived from
hydrogen su! fide and (b) cation exchange in the. cell walls of. Sphagnum
plants. In'contrast, the minerotrophic wetland was neutralized (pH 6.5)
by ground-water inflow containing calcium, and presumably, bicarbonate
ions leached from upland mineral soils.
Less drastic variations in pH (7.1'to 7.5) were noted by Lee et al.,
[5-47] in the study of Wisconsin marshes. High photo synthetic activity
was noted as the cause of major diurnal variations in dissolved oxygen
and concomitant fluctuations in pH. Winter-time decreases in pH were
also noted, and found to be associated with winter-time dissolved oxygen
depletion and production of sulfide.
110
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Studies of the Holland Marsh [5-218] and Jewell Pond [5-217] also
indicated relatively low pH levels of 6.2 to 6.8 and 6.0 to 7.0,
respectively. Hall et al., [5-217] also found low buffering capacity
and tendency for pH to decrease from water surface down into the bottom
muds of the Jewell Pond wetlands.
Levels of pH play an important role in the chemistry and biochemistry of
wetlands in that they may influence the availability of nutrients to
plants and also affect precipitation reactions involving metal ions
[5-216].
o Dissolved Oxygen
Large amounts of photo synthetic activity and accompanying respiration by
macrophytes, epiphytes and benthic algae were found by Lee et al.,
[5-47] to lead to diurnal variations in DO concentrations in waters
discharged from marshes. Winter ranges of 6 to 9.5 mg/1 were observed.
During the summer growing season much greater variation (0 to 8 mg/1)
was noted. In one particular marsh, thermal stratification during the
winter resulted in depletion of DO and production of sulfide.
Throughout the investigation DO was almost always at less than 50
percent of saturation.
Reaeration of natural waters has been studied by many researchers
primarily because of interest in self-purification aspects of streams.
The rate of reaeration of flowing water has been found to vary directly
with flow velocity and channel roughness and inversely with water depth
[5-219, 5-220]. The combined effects of flow resistance from vegetative
cover and regular water movement are generally sufficient to maintain
high DO levels in shallow water wetland areas. In a carefully
controlled study of bog waters, Sparl ing [5-221 ] found that at
velocities greater than 1 cm/s, waters were well agitated and saturated
with oxygen. However, below 0.4 cm/s, reaeration rates were found to be
offset by sediment interaction and root respiration, leading to
depletion in DO levels. Turbulence induced by wind and wave action and
cascading flow, such as over weirs or natural elevation changes, may
also be important aspects of surface water aeration in wetlands [5-222,
5-223].
In tidal wetlands, DO replenishment is a function of the tidal flushing
rate as well as flow velocity [5-55]. Main flow channels tend to
benefit the most. Water within isolated pond areas is not likely to be
renewed with oxygen-rich water as frequently. Such areas are more
highly suceptible to biological activity and may experience drastic
depletion of DO in summer and supersaturation in winter and spring
[5-55],
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Within wetland systems, DO levels may influence other water quality
processes [5-47], These include:
(1) Den-itrification reactions which occur to a significant
extent when low DO or anerobic conditions exist;
(2) Changes in the-oxidation-reduction-potential within
sediments leading to the remobilization of heavy metal
ions: previously bound into stable complexes under aerobic
conditions.
o Electrical Conductivity and Salinity
Electrical: conductivity (EC) serves as a good indicator of the source of
freshwater^in wetlands, such as precipitation, runoff or ground-water
inflow. Values less than 80 ytnho are generally indicative of a perched
water table-condition, whereas values greater than 80 timho tend to
indicate the presence of continuous ground water [5-216]. In his study
of Minnesota .peat wetlands,, Verry found low-EC to be related to
increased streamfTow, probably due to dilution [5-216],
In the study of Jewell Pond [5-217], EC values of 40 to 70 pmho were
observed. Values- tended to increase during spring and summer, reach a
peak in late July or August and decrease in fall and winter.
The Holland -Marsh study [5-217] provided contrast between EC values from
cultivated and uncultivated wetlands. Significantly higher EC in both
subsurface-drainage (90 percent) and surface runoff (88 percent) was
observed in-the;-culttvated area. The proximity of snow melt to bare
soil in-the-cul ti vated area was considered responsible for this
difference. The exposure of bare soil provides greater opportunity for
the sol ution'o f i-ons than in the naturally vegetated marsh. In
addition, greater evaporation rates from the cultivated wetland area
were also suspected to be-contributing factors.
Salinity ..refe'rs,to solutions with high-concentrations of soluble salts,
usually .predominated by sodium cations and.-chloride anions. Seawater
contains^relatively constant concentrations of these major ions and
total salinitycan be calculated on the basis of sodium or chloride ion
concentration. The ionic composition of freshwater is extremely
variable^and thus cannot appropriately be given on a salinity basis.
Saline environments are usually related to areas with tidal exchange or
seawater- intrusion. In inland areas, wetlands without outlet or high
evaporative stress, can also produce saline environments, which in some
cases have higher chloride concentrations than seawater. High salt
concentrations can cause osmotic stress to plants, leading to water loss
from plant'cells, and specific ions may be toxic to some plants. Plants
may take up salts to regulate the internal osmotic balance with external
C9nditions. However, the development of adaptation mechanisms, as
discussed below is common among many types of wetland vegetation.
112
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In general, sedges of Carex sp. and Cyperus sp. thrive only in
freshwater; cattails and rushes can tolerate brackish waters up to about
25 ppt; and reeds, bulrushes, pickleweeds and cordgrasses can tolerate
seawater concentrations (33 to 35 ppt) [5-219], All of the floating and
submerged aquatic vegetation species studied are found only in
freshwater environments although some will tolerate mildly brackish
conditions.
o Color
Wetland environments exhibit large variations in water color due to
interactions between sediments, microorganisms and living and decaying
plant matter. Water color may range from pale yellow to dark oranges
and browns, particularly where bark tannins may contribute strong
effects. In most cases, the color of the water is not necessarily
indicative of poor water quality. towever, in treatment schemes using
vegetative systems, it should be noted that effluent waters can contain
wide color ranges that may or may not be desirable for other uses, such
as drinking water. .
Large variations in color were measured in the Wisconsin, Minnesota and
New Hampshire studies [5-47, 5-216]. Values given in color units (one
color unit is equivalent to the color of 1 mg/1 of platinum as K2PtClg)
ranged as follows:
o Wisconsin marsh - 20 to 120 color units;
o Minnesota peatland - 75 to 890 color units;
o New Hamphsire ponds - 80 to 150 color units.
Values were found to vary inversely with streamflow in the Minnesota
peat wetlands [5-216], Lee et al., [5-47] also found higher values
associated with the breakdown of plant materials at the end of the
growing season, when low flow conditions prevailed. The source of color
is the decomposing organic matter though only a small group of organics
are responsible, for imparting visible color [5-47],
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REFERENCES
5- 1. De Jong, J. Bulrush and Reed Ponds: Purification of Sewage with
the Aid of Ponds with Bulrushes or Reed's. Paper presented at the
International Conference on Biological Water Quality Improvement
Alternatives, Philadelphia, Pa., 1975.
5- 2. Kuenzler, E.J. and A.F. Chestnut. Structure and Functioning of
Es'tuaririe Ecosystems Exposed to Treated Sewage Waste-s. Annual
Report 1970-1971, Nat. Tech. Tnfor. Ser. COM-71-00688,
University of North Carolina, Chapel Hill, N.C., 1971..
5-3. Lugo ,- A'i Optimising the Management'of the Ki'ssimmee River Basin
Marshes for Maximum Value to Man. In: The Kissimmee-Okeechobee
Basin - Report to the Florida Cabinet. Tallahassee, Fla., 1972.
5-4. Nedwel 1, D.B. Inorganic Nitrogen Metabolism in a Eutrophicated
Tropical Mangrove Estuary. Water Res. 9:221, 1975.
5-5. Oduni, H.T. and A.F. Chestnut. Studies' of Marine Ecosystems
Developing with Treated Sewage Wastes. Annual Report 1969-1970,
Nat. Tech. In for. Ser'. PB 199 537, university of North Carolina,
Chapel Hill, N.C., 1970.
5-6. Seidel, K. Macrophytes as Functional Elements in the Environment
of Man. Hydrobiologia 12:121, 1971.
5-7. Spangler, F.L-.-, W.E. Sloey and C.W. Fetter. Experimental Uses
of Emergent' Vegetation for the Biological Treatment of Municipal
Was'tewater in" Wisconsin. Paper presented at the International
Conference on Biological Water Quality Improvement Alternatives,
Philadelphia, Pa., 1975.
5-8. Tall ing, J.F. The' Longitudinal Succession of. the Water
Characteristics in the White7 Nile. Hydrobiologia 11:73, 1957.
5-9. Valiela, I., J.M. Teal and W. Sass. Nutrient Retention in Salt
Ma rs'h" Plots Experimentally Fertilize-d with Sewage SI udge.
Estu:ar. Coastal Mar, Sci. 1:261, 1973.
5-10. Valiela, I., J.M. Teal and S. Vince. Assimilation of Sewage by
Wetlands. Estuar. Processes, 1:234, 1975.
5-11. Le'vitt, J. Responses of Plants to Environmental Stresses.
Academic Press, Inc. New York, N.Y, 1972.
5-12. De Jong, J. The Purification of Wastewater with the Aid of Rush
or Reed Ponds. In: Biological Control of Water Pollution, J.
Tourbier and R.UT Pierson, Jr. (eds). University of Pennsylvania
Press, Philadelphia, Pa., 1976.
114
-------
5-13. Boyd, C.E. Production, Mineral Accumulation and Pigment
Concentrations in Typha latifolia and Sci rpus americanus.
Ecology 51(1):285, ITHT. '
5-14. Volz, M.G. Infestations of Yellow Nutsedge in Cropped Soil:
Effects on Soil Nitrogen Availability to the Crop and on
Associated N Transforming Bacterial Population. Agro-Ecosys.
3:313, 1977.
5-15. Teal, J. M., I. Valiela and D. Berlo. Nitrogen Fixation by
Rhizosphere and Free-Lining Bacteria in Salt Marsh Sediments.
Limnol. Oceangr. 24(2):350, 1979.
5-16. Klopatek, J. Nutrient Dynamics of Freshwater Riverine Marshes and
the Role of Emergent Macrophytes. _In: Freshwater Wetlands:
Ecological Processes and Management Potential, R.E. Good, D.F.
Whigham .and R.L. Simpson (eds). Academic Press. New York, N.Y. ,
1978.
5-17. Lindsley, D., T. Schuck and F. Stearns. Productivity and
Nutrient Content of Emergent Macrophytes in Two Wisconsin
Marshes, In: Freshwater Wetlands and Sewage Effluent Disposal,
D.L. Tilton, R.H. Kadlec and C.J. Richardson (eds). University of
Michigan, Ann Arbor, Mi., 1976.
5-18. Mason, G.F. and R.J. Bryant. Production, Nutrient Content and
Decomposition o f IPhragmites communis and Typha angusti fol ia.
Jour. Ecology 63(1):71, 1975.
5-19. Prentki, R.T., T.D. Gustafson and M.S. Adams. Nutrient Movements
in Lakeshore Marshes. In: Freshwater Wetlands: Ecological
Processes and Management~~Potential, R.E. Good, D.F. Whigham and
R.L. Simpson (eds). Academic Press, New York, N.Y., 1978.
5-20. Tilton, D.L., R.H. Kadlec and C.J. Richardson (eds). Freshwater
Wetlands and Sewage Effluent Disposal. University of Michigan,
Ann Arbor, Mi., 1976. .
5-21. Odum, H.T., K.C. Ewel, W.J. Mitsch and J.W. Ordway. Recycling
Treated Sewage through Cypress Wetlands in Florida. Center for
Wetlands, University of Florida, Gainesville, Fla., 1975.
5-22. Sidle, R.C., J.E. Hook and L.T. Kardos. Heavy Metals Application
and Plant Uptake in a Land Disposal System for Wastewater. Jour.
Environ. Qual. 5(1):97, 1976.
5-23. Welsh, P. and P. Denny. Waterplants and the Recycling of Heavy
Metals in an English Lake. Proc. Trace Subst. Environ. Health
10:157, 1975.
115
-------
5-24. Baudo, R. and P.G. Varini. Copper, Manganese and Chromium
Concentrations in Five Macrophytes from the Delta of River Toce
(Northern Italy). Memorie dell'Istituto di Idrobiologia 33:305,
1976.
5-25. Hutchinson, G.E. A Treatise on Limnology, Vol. Ill:
Ltmnological Botany. John Wiley & Sons, New York, N.Y., 1975.
5-26. Banus, M.D., I. Valiela and J.M. Teal. Lead, Zinc and Cadmium
Bud-gets in Experimentally Enriched Salt Marsh Ecosystems.
Estuar. Coastal Mar. Sci. 3:421, 1975.
5-27. Pellenbarg, R.E. Spartina alterni flora Litter and the Aqueous
Surface Microlayer in the Salt Marsh.Estuar. Coastal Mar. Sci.
6:187, 1978.
5-28. Windom, H.L. Heavy Metal Fluxes through Salt-Marsh Estuaries.
Estuar. Res. 1:137, 1975.
5-29. Windom, H., W. Gardner, J. Stephens and F. Taylor. The Role of
Methylmercury Production in the Transfer of Mercury in a Salt
Marsh Ecosystem. Estuar. Coastal Mar. Sci. 4:579, 1976.
5-30. Marsh, L..C. Studies in the Genus Typha: Autecology with Special
Reference to the Role of Aerenchyma. Biol. Abst. 44:20654, 1963.
5-31. Laing, H.E. The Composition of the Internal Atmosphere of Nuphar
a'dven.um and Other Water Plants. Amer. Jour. Bo t. 27 : 574 ,
December 1940.
5-32. Laiag, H.E. Respiration of the Rhizomes of Nuphar advenum and
Other Plants. Amer. Jour. Bot.. 27:574, July 1940.
5-33. Rich, P.H. and R.A. Kowleczewski. Wetland Metabolism. In:
Proceedings: Third Wetlands Conference. Inst. of Water
Resources, University of Connecticut,'1976.
5-34. Richardson, C.J., D.L. Til tori, J.A. Kadlec, J.P.M. Chamie and
W.A. Wentz. Nutrient Dynamics of Northern Wetland Ecosystems.
In: -Freshwater Wetlands: Ecological Processes and Management
Potential, R.E. Good, D.F. -Whigham and R;L. Simpson (eds).
Academic Press, New York, N.Y., 1978.
5-35. Cook, A.H. and C.F. Powers. Early Biochemical Changes in the
Soils and Waters of Artificially Created Marshes in New York. New
York Fish and Game Jour. 5(1 ):9, 1958.
5-36. Seidel , K. Macrophytes and Water Purification. In: Biological
Control of Water Pollution, J. Tourbier, and R.W. Pierson, Jr.
(eds). University of Pennsylvania Press, Philadelphia, Pa., 1976.
116
-------
5-37. Nikolajevskij, V.6. Research into the Biology of the Common Reed
(Phragmites cpmmunis Trin.) in the U.S.S.R. Folia. Geobot.
Phytotax. 6:221, 1971.
5-38. Phillip, C.C. and R.G. Brown. Ecological Studies of
Transition-Zone Vascular Plants in South River, Maryland.
Chesapeake Sci. 6(2):73081, 1965.
5-39. Haslam, S.M. Biological Flora of the British Isles: Phragmites
communis Trin. Jour. Ecol. 60(2):585, 1972.
5-40. Cavalieri, A»J. and A.H.C. Huang. Evaluation of Proline
Accumulation in the Adaption of Diverse Species of Marsh
Halophytes to the Saline Environment. Amer. Jour. Bo t.
66(3):307, 1979.
5-41. Association of Bay Area Governments. Treatment of Stormwater
Runoff by a Marsh/Flood Basin-Interim Report. Berkeley, Ca.,
August 1979.
5-42. University of California, Davis, Department of Civil Engineering.
The Use and Potential of Aquatic Species for Wastewater Treatment
- Appendix A: The Environmental Requirements of Emergent Aquatic
Plants. Prepared for California State Water Resources Control
Board, Publication It). 65, Draft Report, 1980.
5-43. Kadlec, R.H., D.L. Tilton and J.A. Kadlec. Feasiblityof
Utilization of Wetland Ecosystems for Nutrient Removal from
Secondary Municipal Wastewater Treatment Plant Effluent.
Semi-annual Report to. 5., NSF-RANN Grant AEN75-08855, 1977.
5-44. Burge, W.D. and F.E. Broadbent. Fixation, of Ammonia by Organic
Soils. Soil Sci. Soc. Am. Proceedings 25:199, 1966.
5-45. Van der Vlak, A.G., J.L. Baker and C.B; Davis. Natural
Freshwater Wetlands as Nitrogen and Phosphorus Traps. Journal
Paper No. J-0000. Iowa Agric. and Home Econ. Exp. Sta., Ames,
Iowa, 1978.
5-46. Gosselink, J.G. and R.E. Turner. The Role of Hydrology in
Freshwater Wetland Ecosystem. In: Freshwater Wetlands:
Ecological Processes and Management" Potential, R.E. Good, D.F.
Whigham and R.L. Simpson (eds). Academic Press, New York, N.Y. ,
1978
5-47. Lee, G.F., E. Bentley and R. Amundson. Effect of Marshes on
Water Quality. Water Chemistry Program, University of Wisconsin,
Madison, Wis., 1969.
117
-------
5-48. Uttormark, P.O., J.D. Chapin and K.M. Green. Estimating Nutrient
Loadings of Lakes from Non-Point Sources. Water Resources
Center. University of Wisconsin, Madison, Wis., 1974.
5-49. Wetzel, R..G. Limnology. W.B. Saunders Company, Philadelphia,
Pa-., 1975.
5-50. Bristow, J.M. and M. Whitcombe. The Role of Roots in the
Nutrition of Aquatic Vascular PlantSi Amer. Jour. Bot. 58:8,
1976
5-51. Vail el a, I., J.M. Teal and N.Y. Person. Production and Dynamics
of. Experimental ly Enriched Salt Marsh Vegetation: Below Ground
Biomass. Limnol. Oceanogr. 21:245, 1976.
5-52. Carpenter, E.J., C.D. Van .Raalte and I. Valicla. Nitrogen
Fixation by Algae in a Massachusetts Salt Marsh. Limnol.
Oceanogr. 23(2):318, 1973.
5-53. Keeney, D.R. The Nitrogen Cycle, in Sediment-Water Systems. Jour.
Environ. Qua!. 2(1):15, 1973.
5-54. Chen, R.L., D.R. Keeney, D.A. Graetz and J.A. Holding.
Denitri fication and Nitrate Reduction in Wisconsin Lake
Sediments. Jour. Environ. Qual. (2):158, 1972.
5-55. Simpson, R.L. and D.F. Whigham. Seasonal Patterns of Nutrient
Movement in a-Freshwater Tidal Marsh. In: Freshwater Wetlands:
Ecological Processes and Management: "Potential, R.E. Good, D.F.
Whigham and R.L. Simpson (eds). Academic Press, New York, N.Y.,
1978.
5-56. Keenan, J..D* and M.T. Aner. The Influence of Phosphorus Luxury
Uptake on Algal Bioassays. Jour. Water Poll. Control Fed.
46(3):532,: 1974.
5-57. Blumer, ,K. The Use of Wetlands for Treating Wastes -- Wisdom in
Diversity? In: Environmental Quality through Wetlands
Utilization. Proceedings from a Symposium Sponsored by the
Coordinating Council on the Restoration of the Kissimmee River
Valley and Taylor Creek-Nubbin Slough Basin, Tallahassee, Fla.,
February 29-March 2, 1978.
5-58. Hickok, E.E., M.C. Hannaman and N.C. Wenck. Urban Runoff
Treatment Methods: Volume I - Non-Structural Wetland Treatment.
EPA-600/2-77-217, Cincinnati, Ohio, 1977.
5-59. Sutherland, J.C. and F.B. Bevis. Reuse of Municipal Wastewater
by Volunteer Freshwater Wetlands. In: Proceedings, Water Reuse
Symposium, Vol. 1, Washington, D.C., March 1979.
118
-------
5-60. Tilton, D.L. and R.H. Kadlec. The Utilization of a Freshwater
Wetland for Nutrient Removal from Secondarily Treated Wastewater
Effluent. Jour. Environ. Qual. 8(3):328, 1979.
5-61. Sloey, W.E., F.L. Spangler and C.W. Fetter, Jr. Management of
Freshwater Wetlands for Nutrient Assimilation. In: Freshwater
Wetlands: Ecological Processes and Management "Potential , R.E.
Good, D.F. Whigham and R.L. Simpson (eds). Academic Press, New
York, N.Y. , 1978.
5-62. Odum, E.P. Fundamentals of Ecology. 3rd Edition. W.B. Saunders
Co.9 Philadelphia, Pa., 1971.
5-63. Stewart, K.K. and W.H. Ornes. Assessing a Marsh Environment for
Wastewater Renovation. Jour. .Water Poll. Control Fed.
47(7):1880, 1975.
5-64. Christian, R.R. and W.J. Wiebe. Anaerobic Microbial Community
Metabolism in Spartina alterniflora Soils. Limnol. Oceanogr.
23(2):328, ' ~~
5-65. Kaplan., W., I. Vabiela and J.M. Teal. Denitrification in a Salt
Marsh Ecosystem. Limnol. Oceanogr. 24(4):726, 1979.
5-66. Chen, M. , E. Canelli and 6.W. Fuhs. Effects of Salinity on
Nitrification in the East River. Jour. Water Poll. Control Fed.
47(10):2474, 1985.
5-67. Brezonik, P.L. The Dynamics of the Nitrogen Cycle in Natural
Waters. Ph.D. Dissertation, Department of Water Chemistry,
University of Wisconsin, Madison, Wis., 1968.
5-68. Toetz, D.W. Uptake and Translocation of Ammonia by Freshwater
Hydrophytes. Ecology 55:199, 1974.
5-69. Hutchinson, G.E. A Treatise on Limnology. John Wiley and Sons,
Inc., London, 1957.
5-70. Natarjan, K.V. Toxicity of Ammonia to Marine Diatoms. Jour.
Water Poll. Control Fed. 42(5):1184, 1970.
5-71. Patrick, W.H. and I.C. Maphapatra. Transformation and
Availability to Rice of Nitrogen and Phosphorus in Water Logged
Soils. Advan. Agron. 20:323, 1968.
5-72. Bouldin, D.R., R.L. Johnson, C. Burda and C.W. Kao. Losses of
Inorganic Nitrogen from Aquatic Systems. Jour. Environ. Qual.
3(2):107, 1974.
119
-------
5-73. Brezonfk, P.L. and G.F. Lee. Denitrlfication as a Nitrogen Sink
in Lake Meridota, Wisconsin. Environ. Sci. Techno!. 2:120, 1968.
5-74. Chen, R.L., D.R. Keeney and J.G. Konrad. Nitrification in
Sediments of Selected Wisconsin Lakes. Jour. Environ. Qua!.
1(2):151, 1974. '
5-75. DePinto, J.V. and F.H. Verhoff. Nutrient Regeneration from
Aerobic Decomposition of Green Algae. Environ. Sci. Technol.
11(4):371, 1977.
5-76. Lance, J.C. Nitrogen Removal by Soil Mechanisms. Jour. Water
Poll. Control Fed. 44(7):1352, 1972,
5-77. Patrick, W.H. and K.R. Reddy. Nitrification-Denitrification
Reactions in Flooded Soils and Water Bottoms: Dependence on
Oxygen Supply and Ammonium Diffusion. Jour. Environ. Qual .
5:469, 1976.
5-78. Snarma, B. and R.C. Ahlert. Nitrification and Nitrogen Removal.
Water Res. 11:897, 1977.
5-79. U.S. Environmental Protection Agency. Process Design Manual for
Nitrogen Control. EPA Technology Transfer, 1975.
5-80, Van Kessel, J.F. Factors Affecting the Denitrification Rate in
Two Water-Sediment Systems. Water Res. 11:259, 1977.
5-81. Kholdebarin, B. and J.J. Oerrli. Effect of Suspended Particles
and Their Sizes on Nitrification in Surface Water. Jour. Water
Poll. Control Fed..49(7):1693k 1977.
5-82. Mortimer,. C.H. The Exchange of Dissolved Substances between Mud
and Water in Lakes. Jour. Eco.1; 29:280, and 30:147, 1941.
r
5-83. However,, R*H... The Oxygen Status of Lake Sediments. Jour.
Environ.. Qual. 1(4):366, 1972.
5-84. En:g;ler, R-. Nv and W.H. Pa.tr rck, Jr. Nitrate Removal from
FToddwater Overlying Flooded Soils and Sediments. Jour. Environ.
Qua.l. 3 (4):409, 1974.
5-r85. Bartlett, M..S.., L.C. Brown, N.B. Hanes and N.H. Nickerson.
DenitPification in Freshwater Wetland Soil. M.S. Thesis, Tufts
University, Medford, Mass., 1978.
+
5-86. U.S. Environmental Protection Agency. Process Design Manual for
Land Treatment of Municipal Wastewater. EPA 625/1-77-008,
October 1977.
120
-------
5-87. Middleton, A.C. and A.W. Lawrence, Kinetics of Microbial Sulfate
Reduction. Jour. Water Poll. Control Fed. 49(7):1659, 1977.
5-88. Spangler, F.L, W.E. Sloey and C.W. Fetter. Experimental Use of
Emergent Vegetation for the Biological Treatment of Municipal
Wastewater in Wisconsin. In: Biological Control of Water
Pollution, J. Tourbier and TTTw. Pierson, Jr. (eds). University
of Pennsylvania Press, Philadelphia, Pa., 1976.
5-89. Spangler, F.L., W.E. Sloey and C.W. Fetter. Wastewater Treatment
by Natural and Artificial Marshes. EPA-600/2-76-207, Springfield
Vao 1976.
5-90. Spanglerj F;L., W.E.Sloey and C.W. Fetter. Artificial and
Natural Marshes as Wastewater Treatment Systems in Wisconsin.
In: Freshwater Wetlands and Sewage Effluent Disposal, D.L.
Til ton, R.H. Kadlec and C.J. Richardson (eds). University of
Michigan, Ann Arbor, Mi., 1976.
5-9U Spangler, F.L., C.W. Fetter and W. E. : Sloey. Phosphorus
Accumulation-Discharge Cycles in Marshes. Water Res. Bull.
13(6):1191, 1977.
5-92. University of Cal ifornia, Davis, Department of Civil Engineering.
The Use and Potential of Aquatic Species for Wastewater Treatment
- Appendix A: The Environmental Requirements of Floating Aquatic
Plants. Prepared for California State Water Resources Control
Board, Publication No. 65, Draft Report, 1980.
5-93. University of California, Davis, Department of Civil Engineering.
The Use and Potential of Aquatic Species for Wastewater Treatment
- Appendix A: The Environmental Requirements of Submerged
Aquatic Plants. Prepared for California State Water Resources
Control Board, Publication No. 65, Draft Report, 1980.
5-94. Broome, S.W., W.W. Woodhouse and E.D. Seneca. The Relationship
of Mineral Nutrients to Growth of Spartina alterniflora in North
Carolina: I. Nutrient Status of Plants and Soils in Natural
Stands. Proc. Soil Sci. Soc. Amer. 39(2):295, 1975.
5-95. Chalmers, A.G. The Effects of Fertilization on Nitrogen
Distribution in a Spartina alterniflora Salt Marsh. Estuar.
Coastal Mar. Sci. 8:327, 197£ "~
5-96. Kvet, J. Growth and Mineral Nutrients in Shoots of Typha
latifolia L. Symp. Biol. Hung. 15:113, 1975.
121
-------
5-97. Zdanowski, B., M. Bnlnska, A. Kbrycka, J. -Sosnowska, J. Radziej
and J. Zachwieja. The Influence of Mineral Fertilization on
Primary Productivity of Lakes. Ekologia Pol ska'26(2):153, 1978.
5-98. Dykjova, 0. and D. Hradecka. Production Ecology of Phragmites
communis; I. Relations of Two Ecotypes to the Microclimate and
Nutrient Conditions of Habitat. Folia Geobot. Phytotax. Praha
11(1):23, 1976.
5-99. Bernard, J.M. and F.A. Bernard. Winter Standing Crop and
Nutrient Contents in Five Central New York Wetlands. Bull.
Torrey Bot. Club 104(1)57, 1977.
5-100. Bernard, J.M. and B.A. Sol sky. Nutrient Cycling in a Carex
lacustris Wetland. Can. Jour. Bot. 55(5-8):630, 1977.
5-101. O'Brien, O.J. and F.B. Birkner. Kinetics of Oxygenation of
Reduced Sulfur Species in Aqueous Solution. Environ. Sci .
Techno 1. 11(12):1114, 1977.
5-102. Van Vleet, E.S. and J.G. Quinn. Input and Fate of Petroleum
Hydrocarbons Entering the Providence River and Upper Narragansett
Bay from.Wastewater Effluents. Environ. Sci. Techno!.
11(2):1086, 1977.
5-103. Bole, J...B. and R.G. Bell. Land Application of Municipal Sewage
Waste Water: Yield and Chemical Composition of Forage Crops.
Jour. Environ., Qual. 7(2):222, 1978.
5-104. Gal lagher, .J. L. and F.6. Plumley. Underground Biomass Profiles
and Productivity in Atlantic Coastal Marshes. Amer. Jour. Bot.
66920:156, 1979.
5:-105. Lawrence, T., F.G.. Warder and R. Ashford. Effect of Stage and
Height of Cutting on the Crude Protein Content and Crude Protein
Yield of Intermediate Wheatgrass, Bromegrass, and Reed
Canarygrass. Can. Jour. Plant Sci. 51:41, 1971.
5-106. Patrick, W.H., Jr. and R..D. Delaune. Nitrogen and Phosphorus
Utilization by Spartina allterniflora in a Salt Marsh fn Barataria
Bay, Louisiana.Estuar. Coastal Mar. Sci. 4:59064, 1976.
5-107. Walker, J. D. and R.R. Col well. Oil, Mercury and Bacterial
Interactions. Environ. Sci. Technol. 10(12):1145, 1976.
5-108. Steward, K. K. Nutrient Removal Potentials of Various Aquatic
Plants. Hyacinth Control Jour. (Jour. Aquat. Plant Mgmt.)
8 (2):34, 1970.
122
-------
5-109. Mochnacka-Lawacz, H. The Effects of Mowing on the Dynamics of
Quantity, Biomass and Mineral Contents of Reed (Phragml tes
cqmmunis Trin.). Polskie Archiqum Hydrobiologii 21 (314): 318,
WfiT.
5-110. Stake, E. Higher Vegetation and Phosphorus in a Small Stream in
Central Sweden. Schweiterische Zeitschrift fur Hydrologie
30:353, 1968.
5-111. Walker, J.D., R.R. Colwell and L. Pettakis. Bacterial
Degradation of Motor Oil. Jour. Water Poll. Control Fed.
47(8):2058, 1975.
5-112. Krenkel, P.A. (ed). Heavy Metals in the Aquatic Environment:
Proceedings of the International Conference at Nashville,
Tennessee, 1973. Pergamon Press, Elmsford, N.Y., 1975.
5-113. Broome, S.W., W.W. Woodhouse, Jr. and E.D. Seneca. The
Relationship of Mineral Nutrients to Growth of Spa rt i na
alterniflora in North Carolina: II. The Effects of N, P, and Fe
Fertilizers. Proc. Soil Sci. Soc. Amer. 39(1-3):301, 1975.
5-114. Hook, J.E., L.T. Kardos and W.E. Sopper. Effects of Land
Disposal of Wastewaters on Soil Phosphorus Relations. In:
Recycling Treated Municipal Wastewater and Sludge through Forest
and Cropland. Pennsylvania State University Press, University
Park, Pa., 1973.
5-115. Kardos, L.T. and J.E. Hook. Phosphorus Balance in Sewage
Effluent Treated Soils. Jour. Environ. Qua!. 5(1):87, 1976.
5-116. Boyd, C.E. and W.W. Walley. Studies of the Biogeochemistry of
Boron: I. Concentrations in Surface Waters, Rainfall and
Aquatic Plants. Amer. Midlands Natur. 88(1):1, 1972.
5-117. Gearing, P.J., J.N. Gearing, R.J. Pruell, T.L. Wade and J.G.
Quinn. Partitioning of No. 2 Fuel Oil in Controlled Estuarine
Ecosystems, Sediment and Suspended Particulate Matter. Environ.
Sci. Technol. 14(9):1129, 1980.
5-118. Cowgill, U.M. The Hydrogeochemi stry of L'insley Pond, North
Branford, Connecticut: II. The Chemical Composition of the
Aquatic Macrophytes. Arch. Hydrobiol., Suppl. 45(1):1, 1974.
5-119. Morozov, N.V. and A.V. Torpischeva. Microorganisms that Oxidize
Petroleum and Petroleum Products in the Presence of Higher
Aquatic Plants. Hydrobiol. Jour. 9:54, 1973.
123
-------
5-120. Merzhko , A.L. Role, of Higher Aquatic Plants in the
Self-Purification of Lakes and Streams. Hydrobiol. Jour. 6:91,
1970.
5-121. Vrochinskiy, K.K., I.V. Grib and A.V. Grib. The Content of
Organo-Chlorine Insecticides in Aquatic Plants. Hydrobiol. Jour.
6:91, 1970.
5-122. Wolverton, B.C. and D.D. Harrison. Aquatic Plants for Removal of
Mevinphos from the Aquatic Environment. Jour. Miss. Acad. Sci.
19:84, 1973-74.
5-123. Boyd', C.E. Vascular Aquatic Plants for Mineral Nutrient Removal
from Polluted Waters. Econ. Bot. 24(1):95, .1970.
5'-124. Dykyjova, D. Nutrient Uptake by Littoral Communities of
He-lpphytes. In: Pond Littoral Ecosystems: Structure and
Functioning, DTTtykyjova and J. Kvet (eds). Springer-Verlag, New
York, N.Y., 1978.
5-125. Varenkb, N.I. and V.T. Chuiko. Role of'Higher Aquatic Plants in
the Migration of Manganese, Zinc, Copper and Cobalt in the
Dneprodzerzhinsk Reservoir. Hydrobiol. Jour.. 7:45, 1971.
5-126. Boyd, C.E. The Dynamics of Dry Matter and Chemical Substances in
Juncus effusus Population. Amer. Midlands Natur. 86:28, 1971.
5-127. Eriksson, C. and D.C. Mortimer. Mercury Uptake in Rooted Higher
Aquatic Plantrs;: Laboratory Studies. Int. Assoc. Theor. Appl.
Limnol. 19:2087 1975, .
5^-128. Bahus, M., I.Valiela and J.M. Teal. Export of Lead from Salt
Marshes. Mar. Poll. Bull. 5:6, 1974.
5:-129. Gardner, W.S., D.R. Kendall, R.R. Odum, H.L. Windorii and J.A.
Stephens. The Distribution of Methyl Mercury in a Contaminated
Salt Marsh Ecosystem. Environ. Pollut. 15:243, 1978.
5>-130. Pomeroy, L.R., R.E. Johannes, E.P. Odunv and B. Roffman. The
Phosphorus and Zinc Cycles and Productivity of a Salt Marsh.
Radioeco-logy 2nd Nat. Sym., 1967.
5-131. Gordon, D.C., Jr., P.O. Keizer, W.R. Hardstaff and D.G. Aldous.
Fate of Crude Oil on Seawater Contained in Outdoor Tanks.
Environ. Sci. Techno!. 10(6):580, 1976.
5"-132. William, R.B. and M.B. Murdoch. The Potential Importance of
Spartina alterniflora in Conveying Zinc, Manganese, and Iron into
Estuarine Food Chains. Radioecology 2nd Nat. Sym., 1967.
124
-------
5-133. Polisini, J.M. and C.E. Boyd. Relationships between Cell-Wall
Fractions, Nitrogen, and Standing Crop in Aquatic Macrophytes.
Ecology 53(1):484, 1972.
5-134. Boyd, C.E. Production, Mineral Nutrient Absorption, and
Biochemical Assimilation by Justicia americana and Alternanthera
philoxerodies. Archiv. Hydrobiol. 66(2):139, 1969.
5-135. Kvet, J. Mineral Nutrients in Shoots of Reed (Phragmites communis
Trin.). Polskie Archiwum Hydrobiologii 20(1):137, 1973.
5-136. Mason, C.F. and R.J. Bryant. Production, Nutrient Content and
Decomposition of Phragmites communis Trin. and Typha angustifolia
U Jour. Ecol. 63(1): 71, 1973:
5-137. Wolverton, B.C. and R.C. McDonald. Water Hyacinth Sorption Rates
of Lead, Mercury and Cadmium. In: Compiled Data on the Vascular
Aquatic Plant Program: 1973^1977, NASA. National Space
Technology Laboratories, Bay St. Louis, Miss., March 1978.
5-138. Hutchinson, T._C. and H. Czrska. Heavy Metal Toxicity and
Int. Assoc. Theor. Appl.
Hutchinson, T.C. and H. Czrska. Hea
Synergism to Floating Aquatic Weeds.
Limnol. Proc. 19(3):2102, 1975.
5-139. Kenny-Wallace, G. and 6.E. Blackman. The Uptake of Growth
Substances: XIV. Patterns of Uptake by Lemna mi no r of
Phenoxyacet i c and Benzoic Acids Following Progressive
Chlorination. Jour. Exper. Bot. 23(7):114, 1972.
5-140. Duffer, W.R. and J.E. Mayer. Municipal Wastewater Aquacul ture.
Environmental Protection Technology Series, EPA-600/2-78-110,
1978.
5-141. Shore, F., W. Vanzandt and W. Smith. Water Hyacinths for Removal
of Toxaphene from Water. Jour. Miss. Acad. Sci. 22 (Suppl): 17,
1977.
5-142. Wolverton, B.C. and M.M. McKown. Water Hyacinths for Removal .of
Phenols from Polluted Waters. Aquat. Bot. 2:191, 1976.
5-143. Blackman, G.E. and J.A. Sargent. The Uptake of Growth Substances
- II: The Absorption and Accumulation of 2: 3:5-Triiodobenzoic
Acid by the Root and Frond of Lemna minor. Jour, Ex p. Bot.
10(30):480, 1959.
5-144. Blackman, G.E., G. Sen, W.R. Birch and R.G. Powell. The Uptake
of Growth Substances - I: Factors Controlling the Uptake of
Phenoxyacetic Acids by Lemna minor. Jour. Exp. Bot. 10(28):33,
1959.
125
-------
5-1-45. Ullrich-Eberius, C.L., A. Novacky and U. Luttge. Active Hexose
Uptake in 'Lemna gibba L. Planta 139(2):149, 1978.
5-146. Bingham, S.W. and R.L. Shaver. Diphenamid Removal from Water and
Metabolism by Aquatic* Plants. Pest. Biochem. Physiol. 7:8, 1977.
5-147. Sutton, Di-L. and R.L. Blackburn. Uptake of Copper by Water
Hyacinth. Hyacinth Control Jour. (Jour. Aquat. Plant Mgmt.)
9 (I): 18, 1971.
5-148. Vrochtnskiy,-K.K., I.V. Grib and A.V. Grib. The Content of
Organb-Chlorine- Insectides in Aquatic Plants. Hydrobiol. Jour.
6:"91, 1970.:
5-149. Coo.ley, Tt N. and D.F. Martin. Studies of the Uptake and
Distribution of Various Metals in Water Hyacinth. Fla. Sci. 39
(Supp'l, a ):19 -(Abstract), 1976.
5-150. Cooley, . T.'N;., D.F; Martin, '.W,C. Durden,. Jr. and B.D. Perkins. A
PrelHmfriapy'Study of Metal Distribution°in Three Water- Hyacinth
Biotypes. Water Res. 13:343, 1979.
5-151. Sutton, DiL. and. R.D. Blackburn. Uptake of Copper by
Parrotfeather and Water Hyacinth. So; Weed Sci. Soc. Proc.
24:331 (Abstract), 1971.
5-152. Wolverton, B.C. Water-Hyacinths for Removal of Cadmium and Nickel
from Polluted.-Waters. NASA Technical Memorandum TM-X-72721,
National Space-Technology Laboratories, Bay St. Louis, Miss.,
1975.
5-153. Wolverton, B.C., R.M. Barlow and R.C. McDonald. Application of
Vascular Aquatic Plants for Pollution Removal, Energy, and Food
Production in a Biological System. In: Biological Control of
Water Pollution, J. Tourbier and R.W. Pierson, Jr. (eds).
University-of Pennsylvania Press, Philadelphia, Pa., 1976.
5-154. Wol vertbn i. B.C. and R.C. McDonald.. Bio-Accumulation and
Detection of Trace Levels of Cadmium in Aquatic Systems Using
E.ichhflrnia crasSipe.s. In: Compiled Data on the Vascular Aquatic
Plant Program: 1975-1977. National Space Technology Laboratory,
NASA. Presented at the National Institute of Environmental
Heal th Sciences'Workshop on Higher Plant Systems as Monitors of
Environmental Mutagens, Marineland, Fla., January 16-18, 1978.
5-155. Wolverton^ BiC. and R.C. McDonald. Wastewater Treatment
Utilizing Water Hyacinths (Eichhornia crassipes). In Compiled
Data on the Vascular Aquatic Plant Program: 1975-19777 National
Space Technology Laboratory, NASA. Presented at the 1977
National Conference on Treatment and Disposal of Industrial
Wastewaters and Residues, Houston, Tx., April 26-29, 1977.
126
-------
5-156. Wolverton, B.C. and R.C. McDonald. Water Hyacinths and Alligator
Weeds for Removal of Silver, Cobalt and Strontium from Polluted
Waters. NASA Technical Memorandum TM-X-72727, National Space
Technology Laboratories, Bay St. Louis, Miss., May 1975.
5-157. Wolverton, B.C., R.C. McDonald and J. Gordon. Water Hyacinths and
Alligator Weed for Final Filtration of Sewage. National Space
Technical Laboratories, Bay St. Louis, Miss., 1975.
5-158. Allenby, K.G. Some Analysis of Aquatic Plants and Waters.
Hydrobiologia 32:486, 1968.
5-159. Allenby, K.G. The Manganese and Calcium Contents of Some Aquatic
Plants and the Water in Which They Grow. Hydrobiologia 29:239,
1967.
5-160. Mangi , J., K. Schmidt, J. Pankow, L. Gaines and P. Turner.
Effects of Chromium on Some Aquatic Plants. Environ. Pollut.
16:285, 1978.
5-161. Rodgers, J.H., Jr., D.S. Cherry and R.K. Guthrie. Cycling of
Elements in Duckweed (Lemna perpusilla) in an Ash Settling Basin
and Swamp Drainage System. Water Res. 12:765, 1978.
5-162. Silvey, W.D. Occurrence of Selected Minor Elements in the Waters
of California. U.S. Geological Survey Water-Supply Paper 1535-L,
Washington, D.C., 1967.
5-163. Jackson, G.A. and J.J. Morgan. Trace Metal-Chelator Interactions
and Phytoplankton Growth in Seawater Media: Theoretical Analysis
and Comparison with Reported Observations. Limnol. Oceanogr.
23(2):268, 1978.
5-164. Young, M. and A.P. Sims. The Potassium Relations of Lemna minor
L. : Potassium Uptake and Plant Growth. Jour. Exp. Bot.
23(77):958, 1972.
5-165. Hill, B.H. Uptake and Release of Nutrients by Aquatic
Macrophytes. Aquat. Bot. 7:87, 1979.
5-166. McNabb, C.D., Jr. The Potential of Submersed Vascular Plants for
Reclamation of Wastewater in Temperate Zone Ponds. In:
Biological Control of Water Pollution, J. Tourbier and R.W.
Pierson, Jr. (eds). University of Pennsylvania Press,
Philadelphia, Pa., 1976.
5-167. Zdanowski, B., M, Bninska, A. Korycka, J. Sosnowska, J. Radziej
and J. Zachwieja.' The Influence of Mineral Fertilization on
Primary Productivity of Lakes. Ekologia Polska 26(2):153, 1978.
127
-------
5-168. Steward, K.K. Nutrient Removal Potentials of Various Aquatic
Plants. Hyacinth Control Jour. (Jour. Aquat. Plant Mgmt.)
8(2):34, -1970.
5-169. Stakei E. Higher Vegetation and Phosphorus in a Small Stream in
Central Sweden. Scheitzerische Zeitschrift fur Hydrologie
30:353, 1968.
5-170. Cartgnan, R. and J. Kalff. Quantification of'the Sediment
Phosphorus Available to Aquatic Macrophytes~ Jour. Fish. Res.
Board Can. 36:1002, 1979.
5-171; GTandori, R.P. and C.D; McNabb. The Uptake of Boron by Lemna
minort Aquat. Bot. 4:53, 1978.
5-172. Alexander, Masson. Biodegradation of Chemicals of Environmental
Concern. Science 211:132, 1981.
5-173. Alexander, M; Jn: Microbial Degradation of Pollutants in Marine
Environments. A.W. Bourquin and P.H. Pritchard (eds). U.S.
Environmental Protection Agency, Gulf Breeze, Fla., 1979.
5-174. Mclntoshj A;W.,:B.K. Shephard, R.A. Mayes and G.S. Atchison. Some
Aspects of Sediment Distribution and Macrophyte Cycling of Heavy
Metals in a Contaminated Lake. Jour. Environ. Qual. 7(3):301,
1978.
5-175. Murzi'na, T.A., I.P. Lubyanoy and A.M. Chaplina. Accumulation of
Strontium 90 by- Freshwater Plants in the Ukrainian Steppe Zone.
Hydrobiol. Jour. 12:66, 1976.
5-176.- 0,phel , I.L. and C.D. Fraser. Calcium and Strontium
Discrimination by Aquatic Plants. Ecology 51(19):324, 1970.
5-177. Ra'y, S. and W. White. Selected Aquat'ic'Plants as Indicator
Specie's for Heavy Metal Pollution. Jo'ur. Environ. Sci. Health
A-ll(12):717, 1976.
5-178. Shar'pte,'V. and P. Denny. Electron Microscope Studies on the
Absorption and Localization of Lead in the Leaf Tissue of
Patamge'ton pectjnatus L. Jour. Ex p. Bot. 27(101):1155, 1976.
5-179. Jona's, R.B. arid F.K. Pfaender. Chlorinated Hydrocarbon
Pesticide's in Western North Atlantic Ocean. Environ. Sci.
Techno!. 11(5):442, 1977.
f
5-180;-Welsh, P. and P. Denny. Waterplants arid the Recycling of Heavy
Metals in an English Lake. Proc. Trace Subst. Envi'ron. Health
10:157, 1975.
128-
-------
5-181. Ernst, W.H.O. and M.M. van der Werff. Aquatic Angiosperms as
Indicators of Copper Contamination. Archiv. Hydrpbiol. 83(3):356,
1978.
5-182. Furnica, G.H., 0. Bolder, E. Dobrescu, S. Bulan and V. Dobrescu.
Studies on the Concentration Factor of Co-57 and Sr-85,
Radionuclides from the Water in Elodea canadensis. A.C.T.A.,
Lucrarile Gradiniii Botanice din Burcuresti, 1974.
5-183. Kinkade, M.L. and H.E. Erdman. The Influence of Hardness
Components (Ca 2+ and Mg 2 +) in Water on the Uptake and
Concentration of Cadmium in a Simulated Freshwater Ecosystem.
Environ. Res. 10:308, 1975.
5-184. Kelchkovskii , V.M., G.G. Polikarpov and R.M. Aleksakhin (eds).
Radioecology. Chapter 15. Wiley Press, New York, N.Y., 1973.
5-185. Kulikov, N.V., S.A. Lyubimova and N.A. Timofeeva. The Role of
Freshwater Plants in Processes of Cpprecipitation of Strontium-90
with Calcium Carbonate. Ecology 51:315, 1970.
5-186. Leinerte, M.P. Influence of External Irradiation of. Higher
Aquatic Plants on Their Accumulation of Sr-90, Cs-137,Ce-144.
Radiobiologia 9:131, 1969. ,
5-187. Mayes, R.A. and A.W. Mclntosh. Uptake of Cadmium and Lead by a
Rooted Aquatic Macrbphyte (Elodea canadensis). Ecology 58:1176,
1977.
5-188. Mortimer, D.C. and A. Kudo. Interaction between Aquatic Plants
and Bed Sediments in Mercury Uptake from Flowing Water. Jour.
Environ. Qual. 4(4):491, 1975.
5-189. Saenko, G.N., A.V. Karyakin, V.E. Krauya and M.M. Farafonov.
Distribution of Certain Metals in Plants. Fiziol Rast.
15(1):115, 1968.
5-190. Cowgill, U.M. Biogeochemi stry of the Rare-Earth Elements in
Aquatic Macrophytes of LinsTey Pond, N. Branford, Connecticut.
Geochimica et Cosmochimica ACTA 37:2329, 1973.
5-191. Fang, S.C. Uptake, Distribution and Fate of Hg-203 Etyhlmercuric
Chloride in the Guppy and Coontail. Environ. Res. 8:112, 1974.
5-192. Mayes, R. and A. Mclntosh. The Use of Aquatic Macrophytes as
Indicators of Trace Metal Contamination in Freshwater Lakes.
Proc. Trace Subs. Environ. Health 157-167, 1975.
129
-------
5-193. Mudroch, A. and J.A. Capobianco. Effects of Mine Effluent on
Uptake of Co, Ni , Cu , As, Zn , Cd , Cr and Pb by Aquatic
Macrophytes. Hydrobiologia 64(3):223, 1979,
5-194. Mudroch, A. and J.A. Capobianco. Effects of Treated Effluent on
a Natural Marsh. Jour. Water Poll. Control. Fed. 51 ('9): 2243,
1979.
5-195. Mudroch, A. and J. Capobianco. Study of Selected Metals in
Marshes on Lake St. Clair, Ontario. Archiv. Hydrobiol. 84(1):87,
1978.
5-196, Ozi-mek, T. Effect of Municipal Sewage on the Submerged
Macrophytes of a Littoral Lake. Ekol. Pol. 26(1):3, 1978.
5-197. Grace, J.B. and R.G. Wetzel. The Production Biology of Eurasian
Watermilfoil (Myriophyllum spicatum L.): A Review. Jour. Aquat.
Plant Mgmt. 16:1, 1978.
5-198. Ryan, J.B., D.N. Riemer and S.J. Toth. Effects of Fertilization
on Aquatic Plants, Water and Bottom Sediments. Weed Sc i.
29(5):482, 1972.
5-199. Gerlaczynska, B. Distribution and Biomass of Macrophytes in Lake
Dgal Maly. Ekologia Pol ska 21:743, 1973. ,
5-200. Adams, M.S. and M.D. McCracken. Seasonal Production of the
Myriophyllum Component of the Littoral of Lake Wingra, Wisconsin.
Jour. Ecol. 62(2):457, 1974.
5-201. Carpenter, S.R. and M.S. Adams. The Macrophyte Tissue Nutrient
Pool of a Hardwater Eutrophic Lake: Implications for Macrophyte
Harvesting. Aquat. Bot. 3:239, 1977.
5-202. Saeger, V.W. and Q.E. Thompson. Biodegradabi1ity of
Halogen-Substituted DiphenyTmethanes. Environ. Sci. Techno!.
14(6):705, 1980.
j .... .
5-203..Syers, J.K., R.F. Harris and D.E. Armstrong. Phosphate Chemistry
in Lake Sediments. Jour. Environ. Qual. 2(1):1, 1973.
5-204. Frost, T.P., H.J. Turner, R.E. Towne and R.H. Estabrook. The
Effectiveness of Duckweed Harvesting as a Nutrient Reduction
Measure in Stabilization Ponds. New Hampshire Water Supply and
Pollution Control Commission, Report ND. 80, 1976.
t j
5-205. Patrick, W.H. and R.A. Khalid. Phosphate Release and Sorption by
Soils and Sediments: Effects of Aerobic and Anerobic Conditions.
Science 186:53, 1974.
130
-------
5-206. Duffer, W.R. and J.E. Mayer. Municipal Wastewater Aquaculture.
Environmental Protection Technology Series, EPA-600/2-78-110,
1978.
5-207. Sebetich, J.J. Phosphorus Kinetics of Freshwater Microcosms.
Ecology 56(6):1262, 1975.
5-208. Wildung, R.E., R.L. Schmidt and A.R. Gahler. The Phosphorus
Status of Eutrophic Lake Sediments as Related to Changes in
Limnological Conditions - Total, Inorganic, and Organic
Phosphorus. Jour. Environ. Qual. 3(2):133, 1974.
5-209. Rigler, F.H. The Phosphorus Fractions and the Turnover Time of
Inorganic Phosphorus in Different Types of Lakes. Limnol.
Oceanogr. 9:511, 1974.
5-210. Vanderborgh, N.E. and A.G. Buyers. Phosphate Removal by Algal
Systems. Jour. Water Poll. Control Fed. 46(4): 727, 1974.
5-211. Carberry, J.B. and M.W. Tenney. Luxury Uptake of Phosphorus by
Activated Sludge. Jour. Water Poll. Control 'Fed.' 45(12):2444,
1973.
5-212. Vrochinskiy, K.K., I.V. Grib and A.V. Grib. The Content of
Organo-Chlorine Insectides in Aquatic Plants. Hydrobiol. Jour.
6:91, 1970.
5-213. Ware, G.W., M.K. Dee and W.D. Cahill. Water Florae as Indicators
of Irrigation Water Contamination by DDT. Bull. Environ. Contam.
Tox. 3(6):333, 1968.
5-214. Bingham, S.W. Improving Water Quality by Removal of Pesticide
Pollutants with Aquatic Plants. VPI-WRRC-BULL 58, Water
Resources Research Center, Virginia Polytechnic Inst. and State
University, Blacksburg, Va., 1973.
5-215. Sutton, D.L. and S.W. Bi.ngham. Absorption and Translocation of
Simazine in Parrotfeather. Weed Sci. 17(4):431, 1969.
5-216. Verry, E.S. Streamflow Chemistry and Nutrient Yields from
Upland-Peatland Watersheds .in Minnesota. Ecology 56:1149, 1975.
5-217. Hall, F.R4, R.J. Rutherford and G.L. Byers. The Influence of a
New England Wetland on Water Quantity and Quality. Project No.
A-015-NH, Water Resource Research Center, University of New
Hampshire, Durham, New Hampshire, 1972.
5-218. Nicholls, K.H. and H.R. Mac Crimmon. Nutrients in Subsurface and
Runoff Waters of the Holland Marsh, Ontario. Jour. Environ.
Qual. 3(1).-31, 1974.
131
-------
5-219. Bennett, J.P. and R.E. Rathbun, Reaeration in Open-Channel Flow,
U.S. Geological Survey, Professional Paper 737, 1972.
,5-220. Tsiuoglow, E.G. and J.R. Wallace. Hydraulic .Properties Related
to Steam Reaeration. Georgia Institute of Technology, Atlanta,
Ga., 1970.
5-221. Sparking, J.H. Studies on the Relationship between Water Nbvement
and Water Chemistry in Mires. Can. Jour. Bot. 44:747, 1960.
5-222. Holley, E.R. and K.K. Klintworth.. Influence of Turbulence on
Surface Reaeration. Water Resources Center Report, University of
Illinois, Urbana, 111., September 1966.
5-223. Juliano, David W. Reaeration Measurements in an Estuary. Jour.
San. Eng. Div., ASCE, December 1969.
5-224. Stowell , R., R. Ludwig, J.Colt and G. Tchobanoglous. Toward the
Rational Design of Aquatic Treatment Systems. .Presented at ASCE
Spring Convention, April 14-18, 1980. Portland, Ore., 1980.
132
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SECTION 6
HYDROLOGIC PROCESSES
Hydrology plays an important role in wetland and upland areas in terms
of ecosystem characteristics and pollutant removal capabilities. The
primary focus of this study is on wetland systems. The first part of
this section is devoted to an examination of hydro logic processes and
characteristics of wetlands.
WETLAND HYDROLOGY - CHARACTERISTICS AND PROCESSES
Wetlands occur in a wide range of climatic, topographic, geologic and
hydrologic settings, encompassing diverse ecosystem types. Examples.
include: northern peatlands, bogs, and cattail marshes; pocket marshes
and swamplands of the south; salt and freshwater tidal marshes of the
Atlantic, Pacific and Gulf Coast regions; and marshes associated with
high-energy rivers such as the Mississippi [6-1]. These fall generally
into the hydrogeologic categories established by Cowardin et al. [6-2]
namely, (a) riverine, (b) lacustrine, (c) palustrine and (d) estuarine
(tidal). Even within these categories, diversity of hydrogeologic
conditions are exhibited by wetlands.
A clear knowledge of wetland hydrology is crucial to an understanding of
the wetland environment and its potential utility in the assimilation of
water-borne pollutants.' Two aspects should be considered:
(1) Watershed hydrology, i .e., how wetlands relate to the
watershed, of which they are an integral feature, in
: terms, 9f hydrologic response;
(2) Ecosystem hydrology, i.e., how hydrologic factors within
wetlands relate to ecosystem characteristics and
processes.
Watershed Hydrology
Wetlands are not isolated landmarks but are rather transition zones
occurring in response to specific watershed or basin-wide hydrogeologic
conditions. They exist primarily in flat to gently sloping terrain, are
periodically flooded, and have ground water at or above the surface of
the ground for major portions of the year. Beyond this cursory
understanding, very little has been done to rigorously assess the
133
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relationships between wetlands and watershed hydrology. The study of
these relationships is receiving attention due :to increased interest in
the connection between land development activities, water pollution
control, water-supply development and wetland values [6-3, 6-4, 6-5].
In connection with land use planning studies in New England, O'Brien and
Motts [6-5] sought to establish a system for classifying and evaluating
hydrogeologic conditions of wetlands. The objective was to identify key
watershed factors which produce significant hydrologic responses in
wetlands.; This would allow better assessment of impacts of potential
land use decisions. The listing of significant factors developed for
wetlands typical of the New England area are presented in Table 28.
They are arranged under three/main categories: geologic, hydrologic and
topographic. .
A brief review of the various factors cited in Table 28 provides insight
into the hydrogeologic characteristics which distinguish Wetland systems
and their respective relationship to surface and .ground-water regimes.
Geology
Geologic-conditions are a major determinant of1the structure of the
watershed and corresponding runoff characteristics. The nature and
extent of geologic formations influence, subsurface water movement and
exchanges with wetlands. A study by Verry [6-6] on Minnesota peatlands
showed that geology has a profound impact on wetlands in terms of (a)
hydrologic.inputs, and (b) sources and'quality of-water. The hydrologic
connection between wetlands and bedrock can be an indication of the
permanence of water-supply to the wetland.
Hydrologic.Factors
o Hydrologic; Position
From a hydrologic standpoint, the occurrence and level of ground water
i s; the most significant factor affecting wetland conditions and
hydrologic-responses [6-5]. This may be. understood in terms of the
hydrologic position of the wetland in relationship to the principal zone
of saturation. Four typical conditions are depicted in Figure 7:
o water/table wetland;
o perched wetland;
o water table/artesian wetland;
o artesian wetland.
With- respect to hydrologic response; those wetlands perched above the
main zone of. saturation are in a position to recharge ground water,
while those in contact with underlying ground water usually serve as a
discharge a'rea.
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TABLE 28. SIGNIFICANT WETLAND WATERSHED FACTORS'
Factor
Component
Subcomponents
Geologic Surflcial material
Thickness of surfic.ial naterial
Bedrock
Till
Stratified draft
Lake bed
Alluvium
Less than 7.5 n
Between 7.5 and 15 m
Greater than 15 m
Igneous and metamorphic bedrock
Sedimentary bedrock
Hydrologic Hydrologic position
Permeability of the organic layer
Depth of water in the wetland
Transmissivity of aquifer
Ground water outflow
Water quality
Perched wetland
water-table wetland-
Water table/artesian wetland
Artesian wetland . .
High permeability (generally
associated with peat)
Low permeability (generally
associated with muck)
Water stands above the surface
Water lies below the surface
Low traqsmissivity (less than
125 m3/(m)(d))
Moderate transmissivitv
(125 to 500 m3/(m)(d))
'High transmissivlty (greater than
500 °
Water on the wetland surface
Water in ponds and streams
associated with the wetland
.Water in the organic deposits
Water below the organic deposits
(unconfined zone)
Water in deep artesian aquifer
Water in bedrock
'Topographic Topographic position
Wetland size
Wetland Ties near mouth of basin
Wetland located on the floodplain
Wetland near the basin divide
a. Source: reference 6-5.
135
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may be semi-artesian conditions
in wetland area
A. Water-Table Wetland
Wetland Intersects thick uncon-
fined main zone of saturation.
\ ^f
. V to
\'\'. >*/i.
top of main zone of saturation
B. Perched Wetland
Wetland perched above a prin-'
ctple zone of saturation.
potentiometric surface of artesian zone
potentiometric surface of artesian zone
0. o . o saturated shallow zone ,o
h-fi-Lo.o .° . o o o . -o.o'li
r&4
C. Water Table_/._Artesian Wetland
Wetland Intersects thin unconfined rone
underlain by a confining bed which in
turn is underlain by a major artesian
aquifer which "feeds" the shallow un-
confined zone.
, Legend
V/////A Wetland deposit
Stratified drift
Bedrock
D. Artesian Wetland ..
Wetland rests on confining bed and is
"fed" by artesian water flowing through
the confining bed.
Potentiometric Surface,
unconfined shallow zone (Water Table)
Potentiometric surface,
confined zone (Artesian)
Figure 7. Wetland relationships to the principal zone of saturation
(hydrologic position). a
a. Source: reference 6-5.
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o Transmissivlty and Ground-water Outflow Permeability
Relatively little study has been made of the relationship of wetland
soil permeability to basin-wide hydrologic influences [6-5]. The
accumulation of peat results in decreased surface soil permeability and
reductions in recharge to ground waters [6-7], In contrast, cypress
domes and other seepage wetlands are generally characterized by high
permeability rates. This factor is of major importance with regard to
water movement, vegetative responses and filtering capabilities [6-8].
The transmissivity of the underlying aquifer becomes important in
assessing the character of sustained subsurface flow from the wetland
basin and in assessing possible impacts on water quality and quantity.
The ground-water outflow from wetlands is a difficult parameter to
gauge, but an important one in constructing the hydrologic budget. It
is critical in assessing impacts during low flow conditions and in
estimating sustained water yield in wetland areas.
o Depth of Surface Water
The depth of surface water in wetlands may be an important factor
insofar as it affects hydrologic responses of wetlands to runoff events.
Wetlands act generally as regulating reservoirs during high runoff
periods, providing storage to retard .peak flaws. The depth of standing
water influences the available storage .capacity. Additionally, the
depth of water may have a bearing on the .manner in which runoff waters
circulate. Overland or sheet flow conditions will predominate once
normal flow channels are overtopped [6-9].
o Water Quality
An expanded discussion of wetland-water quality relationships is
provided in Section 7. O'Brien and Motts [6-5] distinguish six
hydrologic zones where water quality may be of concern:
o on the wetland surface;
o in ponds and streams associated with wetlands;
o within organic deposits;
o in the unconfined zone below organic deposits;
o in deeper artesian aquifers;
o in bedrock below surficial deposits.
o Topographic Position
The ability of a wetland to modify runoff depends upon its position
within a basin. The nearer the wetland to the basin outlet, the larger
its tributary area and the greater its effect on watershed runoff
response. In terms of ground-water relationships, recharge is likely to
occur along the watershed perimeter, whereas the ground-water discharge
area can be expected at the basin mouth-[6-5].
137
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Ecosystem Hydrology
The fact that wetlands are largely a function of prevailing
hydrogeologic conditions is clear. Moreover, the reciprocal effects of
wetlands on watershed hydrologic responses have been elucidated.
Hydrologic factors also play a significant role in determining ecosystem
characteristics within wetland areas.
Relatively little investigation has been made into the quantitative
aspects of wetlands hydrodynamics. The most thorough examination of the
subject is that by Gosselink and Turner [6-1] on qualitative
relationships between hydrology and ecosystem traits. They propose a
conceptual model, as shown in Figure 8, displaying the connection
between wetland hydrology and physical, chemical and biological
characteristics of a wetland ecosystem. Gosselink and Turner identified
four key hydrologic parameters of most significance to wetland biota:
(1) Source - determines ionic composition, oxygen saturation
and pollutant load; . .. . . .
(2) Velocity - affects turbulence and the ability to carry
suspended particulate matter;
(3) Renewal rate - describes the frequency of replacement of
the water considering water depth, volume, frequency of
inundation and velocity;
(4) Timing - constitutes the frequency of inundation (daily,
seasonal) and its regularity or predictability.
These primary hydrologic factors affect physical and chemical aspects
which in turn influence ecosystem development. The specific ecosystem
characteristics identified by Gosselink and Turner [6-1] fall into four
categories: -. ,. .
o species composition and richness;
o primary productivity;
o organic deposition and flux;
o nutrient cycling.
Some of the key processes and relationships linking hydrologic factors
and ecosystem characteristics are summarized in Table 29. A general
conclusion that may be drawn from the information in Table 29 is that
water movement through wetlands has'a positive influence on the health
and character of the ecosystem.
As indicated in Gosselink and Turner's conceptual model (Figure 8), the
physical and biological development of a wetland ecosystem may exert
certain feedback influences upon the hydrologic regime. These are
138
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Solar Radiation
Temperature
Precipitation
Relative Humidity
Cyclic Regularity
] HYDROLOGY
CHEMICAL AND PHYSICAL
PROPERTIES OF SUBSTRATE
allowing
specific
3|
BIOTIC ECOSYSTEM RESPONSE
A» organic
matter
accumulates It
modifies
hydrology
Local Climatic Regli
Figure 8. General conceptual model of the role of .hydrology in
wetland ecosystems. a
a. Source: reference 6-1.
139
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TABLE 29, WETLAND ECOSYSTEM RESPONSES TO VARIOUS HYDROLOGIC FACTORS
Ecosystem
characteristics
Species
composition
and
richness
Source
o Nutrient overload :
may alter species
diversity (6-10)
Hydrologlc factors
Velocity Renewal rate
o Affects distribution o Provides vehicle for
8 deposition of sedl- water movement and
ments, Influencing ele- circulation (6-1)
vation and plant
zonatlon (6-11) o Uniform mixing leads
Timing
Primary
Productivity
.£=.
O
b Species richness found
to Increase directly
with velocity (6-12)
o Affects availability
of dissolved nutria
ents for plant growth
(6-1)
o Sediment Inflow In-
creases substrate
density, leading to
more vigorous plant
growth (6-13)
o Salts, pesticides
and other toxins
detrimental to
productivity
(6-1,6-14)
o Increased velocity
related to greater
sediment input and
Increased plant
growth(6-1)
o "Edge-effect"stim-
ulation of production
along channels due
to Increased velo-
city (6-15,6-1 6,6-1 7)
o Affects flow and
availability of
toxins (6-18)
o Stagnant waters
linked to anaerobic
conditions and plant
stress (6-14,6-19)
o Dissolved oxygen re-
lated to velocity (6-
to monospeclflc stands
of vegetat1on(6-l)
o Diversity tends to In-
crease with elevation,
which is Influenced by
flooding duration &
depth (6-12)
o Availability of water
seems to control, lat-
eral spread of ombro-.
trophic bogs(6-21)
o Availability of nu-
trients for plant
growth related to
availability of water(6-
o Regular renewal of
water In tidal areas
minimizes .salt ac-
cumulation-and plant
stress(6-18)
o Regular renewal sup-
plies 0?, minimizing
stressful anaerobic
conditions; depth &
duration of flood-
ing most Important
20) (6-1, 6-19)
o Timing or seasonal1ty
of rain Input may af-
fect lateral and ver-
tical spread of ombro-
trophic bogs (6-22)
o Frequency of flooding .
Influences availability
1) of toxins to wetland
flora and fauna(6-l)
-------
TABLE 29. (continued)
Ecosystem
characteristics Source
Organic -.
deposition : '
. and flux
Hydrologlc
Velocity
o Rate of total par-
tlculate and total
organic export dir-
ectly proportional
to flow rate (and
velocity) (6-23)
factors
Renewal rate
o Increased flow rate
related to greater
silt Input and organic
matter outflow (6-23)
Timing
o Flooding frequency dir-
ectly related to silt
Input and organic matter
outflow (6-18)
o Soil organic concentra^
Nutrient
cycling
o Influences nutrient
loading and acidity
(6-25)
Qnibrotrophlc bogs--
nutrient poor
o Influences mass
loading, transport
and flux of
nutrients (6-1)
tlon Increases on gradi-
ent from actively flooded
stream banks to less
actively flooded Inland
high marshes (S-24)
o Nutrient flux re-
lated to timing of
flooding with respect
to plant growth cycle.
(6-1)
Hinerotrophlc bogs-
nutrient rich
-------
associated with various aspects of wetland succession. Classical
feedback loop:s: involve organic accumulation, sediment deposition and
nutrient flux.
The growth of vegetation within wetlands acts to increase the depth of
sediment. Plant production supplies organic matter which is available
for deposition and incorporation in sediments as peat. The vegetation
itself acts as a physical silt trap, increasing the sedimentation rate.
With increasing elevation, the frequency and depth of inundation
decreases, leading to still greater peat and organic matter deposition.
This vertical growth produces two distinct hydrologic responses: (a)
blockage or diversion of flow; and (b) decreased percolation of surface
waters through organic deposits (peat) [6-12, 6-17].
Also associated with the vertical succession of wetlands is the tendency
to reduce the renewal rate and therefore the nutrient flux across marsh
boundaries. This results in effectively closing the nutrient cycle
[6-1]. .
The maturing processes described here can and do result in dramatic
alterations in biological communities and hydrologic regimes. Often,
however, this development is interrupted by periodic inundation which
tends to alter and simplify the ecosystem. This has been referred to as
"pulse stability" [6-26].
HYDROLOGIC MANAGEMENT OF WETLANDS FOR POLLUTANT REMOVAL
The importance of the: hydrologic regime in relation to wetland ecosystem
characteristics: and processes has been described. Hydrologic factors
play an equally significant role .in governing wetland functions
affecting pollutant removal. A detailed discussion of wetland pollutant
removal mechanisms, including the influence of various hydrologic
factors, was presented earlier in Section. 4. Table 30 provides a
summary of the key hydrologic relationships which may influence wetlands
strategies for pollutant control. ,'..,.
142
-------
Hydrologlc
factors
TABLE 30. RELATIONSHIP OF HYDROLOGIC FACTORS TQ POLLUTANT REMOVAL IN WETLANDS
. Major pollutant .removal mechanisms
Sedimentation
Aeration
Biochemical transformations
Soil adsorption
Velocity and
flowrate
Hater depth
and fluctuation
Detention
time
Circulation and
flow distribu-
tion
Settling of participate matter
Is primary mode of pollutant re-
moval, largely Influenced by
flow velocity (6-27.6-28)
High runoff flows are threat of
washout of nutrients and de-
composing organic matter (6-29,
6-31)
Shallow depths provide for
more effective settling (6-30)
Detention and flow equaliza-
tion minimize downstream
erosion. (5-5)
Participate matter deposi-
tion directly related to
residence time. (6-31)
Flow distribution most Im-
portant factor In determin-
ing effectiveness of meadow-
land treatment--sheet flow
most desirable. (6-9)
Reaeratlon coefficient varies
linearly with velocity (6-34,
6-35,6-20)
DO levels a function of tidal
flushing and rate of water move-
ment (6-38)
High rates of nitrification ex-
pected with flowing water (6-43)
Reaeratlon varies Inversely
with depth (6.34.6-35)
Ponded aater contributes to
anaerobic conditions, particular-
ly In deeper marshes (6-34,S-44)
Fluctuating water level and
exposure of soil to atmosphere
has positive effect on nitri-
fication; little or no effect
on denltrlflcatlon. (6-43)
Water levels responsible for
Oj status of wetlands, and
resultant amount of soil
mtcrobla) activity (6-41)
Fresh and saltwater marsh soils
capable of reducing NO, In
ponded floodwaters through
denltrlflcatlon (6-39,6-40)
BOD removal a function
of residence time In artificial
marshes (6-45)
Denltrlflcatlon In flooded
marsh soils a function of
detention time. (6-40)
DO replenishment associated
with flushing and flow cir-
culation from tidal action
and upstream discharges.
(6-385 . '
(continued)
Nutrient balance related dir-
ectly to hydrologlc balance
(6-41)
High N and P levels associated
with high flowsIndicative of
leaching and flushing of
decomposing organic matter
High flow rates limit con-
tact with soils and seepage
potential (6-8)
Water hyacinth exhibit best
uptake w/shallow water. (6-32)
Many emergent macrophytes per-
form best at maximum depth .
(6-32)
Ponded water may encourage
volunteer wetland species and
biological activity where
previously nonexistent. (6-8)
Nutrient removal directly
related to detention time.
(6-31^-38.6-45)
Well-defined channels allow
passage of water and waste-
water without significant
Interaction with aquatic
plant communities. (6-29)
Maximum P Immobilization
achieved through soil and
organic Utter contact at
lower water levels. 6 cm
depth significantly more
effective than 30 cm In
peatlands. (6-31)
Even distribution of waste-
water over land surface
enhances soil contact and
V removal. (6-31)
Routing of flow to en-
courage contact with mineral
soils Improves P removal.
(6-41.6-42)
-------
TABLE 30. (continued)
Hydro! ogle
factors
Circulation and
flow distribu-
tion (Cont'd.)
Sedimentation
Beaver dans beneficial In.
dispersing flow over meadow-
lands to enhance sedimenta-
tion and filtration. (6-9)
Major pollutant removal mechanisms
Aeration Biochemical transformations
Broad flow distribution leads
to large effective areas tor
biological contact and high
removal rates. (6-31)
Soil adsorption
Soil-water Interface essen-
tial as major site of
sorptlon, deactlvatlon and
denltrlflcatlon. (6-6)
Circuitous flow paths and
sheet flow lead to large ef-
fective areas and good sedi-
mentation. (6-9,6-31,6-32)
Turbulence and
wave action
Seasonal and
climatic factors
Host dramatic sediment re-
ductions associated with
storm episodes In meadow-
landsmore even flow dis-
tribution over wetland. (6-9)
Soil saturation
fteaeratlon a function of
channel roughness. (6-34,6-35)
Hind can be Important In keep-
Ing localized parts of wetland
water aerated and nixed.
(6-36.6-37),
Pond and pond-like areas nearly
depleted of DO In summer and
supersaturated In winter and
spring. (6-29.6-38)
Nitrifying and denitrifying
bacteria limited in activity
during drought or low water
temperatures. (6-28)
Lowering of water table leads
to aeration, mineralization
and greater mobilization of
N. (6-29,6-48)
(continued)
Freezing promotes release of
N and P from plants and
soils for subsequent wash-
out. (6-28,6-29)
Spring snow melt appears
to have flushing effect on
nutrients. (6-28.6-29)
Best nutrient removal In
spring-sunnier growth period.
(6-32}
First flush of wet season may
wash out decaying organic
matter from prior winter.
(6-29)
Temperate systems experience
winter release of nutrients.
(6-46)
Seasonal rainfall and rujioff
important as diluting agent
and to encourage water cir-
culation: (6-47)
Level of soil saturation con-
trols mlcrobial activity.
(6-41)
-------
TABLE 30. (continued)
Hydrologlc
factors Sedimentation
Soil saturation
(Confd.)
Major pollutant removal mechanisms
Aeration
G.U. table within 5-10 cm
of wetland surface promotes
anaerobic (reducing) con-
ditions. (6-49)
Biochemical transformations
Higher respiratory activity
and biological decomposition
with well drained soil con-
ditions. (6-41)
Soil adsorption
Permeability
and ground water
movement
Lowering of water table allows
aeration and decomposition of
organic matter and slug
release of nutrients In next
flush of runoff. (6-29)
Source and amount of g.w.
Inflow Influences pH and
resultant solubility and
precipitation reactions.
(6-6. 6-29)
Seepage wetlands may act
similarly to flood-Irrigation
forage grass systems In
virtual completeness of P
removal. (6-8)
Nitrogen removal through
nltrlflcatlon/denltrlflcatlon
may be excellent In surface
soils and shallow seepage
zone. (6-8.6-27)
-------
REFERENCES
6- 1. Gosselink, J.G. and R.E. Turner. The Role of Hydrology in
Freshwater Wetland Ecosystems. J_n_: Freshwater Wetlands:
Ecological Processes and Management Potential. R.E. Good, D.F.
Whigham and R.L. Simpson (eds). Academic Press, New York, N.Y.,
1978.
6-2. Cowardin, L.M., V. Carter, F..C. Golet and E.T. LaRoe.
Classification of Wetlands and Deepwater Habitats of the United
States. Prepared for U.S. Fish and Wildlife Service, Publication
FWS/OBS-79/31, December 1979.
6- 3. Baker, J.A. Wetland and Water Supply. U.S. Geological Survey
Circular 431, Washington, D.C.., I960.
6- 4. Motts, W.S. and R.W. Heeley. Wetlands and Groundwater. In: A
Guide to Important Characteristics and Values of Freshwater
'WetLands. Water Resources Research Center, Pub. 31, University
of Massachusetts, Amherst, Mass., 1960.
6- 5. O'Brien, A.L. and W.S. Motts. Hydrogeologic Evaluation of
Wetland Basins for Land Use Planning. Water Res. Bull. 785-789,
1980.
6-6. Verry, E.S. Streamflow Chemistry and Nutrient Yields from
.Upland-P.ea.tl.anxl Watersheds in Minnesota. Ecology 56:1149, 1975.
6- 7. Gorham,, E. and R.H. Hofsetter. Penetration of Bog Peats and Lake
Sediments by Tritium from Atmospheric Fallout. Ecology
52(5.):898, 1971.
6- 8. Sutherland, .J.C. and 'F.B. Bevis. .Reuse of Municipal Wastewater
by Volunteer Freshwater Wetlands. Proceedings, Water Reuse
Sympo.si urn, Vol. 1, Washington, D.C., March 1979.
6-9. Morris, F.A., M.K. Morris, T.S. Michaud and L.R. Williams.
Meadowland Natural Treatment Processes in the Lake Tahoe Basin: A
Field .Investigation. U.S. EPA, Environmental Monitoring Systems
laboratory, las Vegas, Nev.., 1-980.
6-10. Steward, K. K., W.H. Ornes. Assessing a Marsh Environment for
W.astewater Renovation. Jo.ur. Water Poll. Control Fed.
47 (7):1880, 1975.
6-11. Hin.de., H.P. Vertical Distribution of Salt Marsh Phanerogams in
Relation to Tide Levels. Ecol. Monogr. 24:209, 1954.
146
-------
6-12. Heinselman, M.L. Landscape Evolution, Peatland Types, and the
Environment in the Lake Agassiz Peatlands Natural Area,
Minnesota. Ecol. Monogr. 40:235, 1970.
6-13. Delaune, R.D., W.H. Patrick, Jr. and J.M. Brannon. Nutrient
Transformations in Louisiana Salt Marsh Soils. Sea Grant Publ.
No. LSU-T-76-009, Louisiana State University Center for Wetland
Resources, Baton Rouge, La., 1976.
6-14. Patrick, W.H., Jr. and D.S. Mikkelsen. Plant Nutrient Behavior
in Flooded Soils. Fertilizer Technology and Use, 2nd ed. Soil
Sci; Soc. Amer., Madison, Wis., 1971.
6-15. Kirby, C.J. and J.6. Gosselink. Primary Production in a
Louisiana Gulf Coast Salt Spartina alterniflora Marsh. Ecology
57:1052, 1976.
6-16. Smalley, A. E. The Role of Two Invertebrate Populations,
Littorina irrorata and Orchelimum fidicinium, in the Energy Flow
of a Salt Marsh Ecosystem. Ph.D. Dissertation, University of
Georgia, Athens, Ga., 1959.
6-17. Buttery, B.R., W.T. Williams, and J.M. Lambert. Competition
between Glyceria maxima and Phragmites cqmmunis in the Region o f
Surlurgham Broad.Jour. Ecol. 53:183, 1965.
6-18. Gosselink, J.G., R.J Reimold, J.L. Gallagher, H.L. Sindom and
E.P. Odum. Spoil Disposal Problems for Highway Construction
through Marshes. Institute of Ecology, University of Georgia,
Athens, Ga., 1971.
6-19. Harms, W.R. Some Effects of Soil Type and Water Regime on Growth
of Tupelo Seedings. Ecology 54:188, 1973.
6-20. Sparling, J.H. Studies on the Relationship between Water Movement
and Water Chemistry in Mires. Can. Jour. Bot. 44:747, 1966.
6-21. Corham, E. The Development of Peat Lands. Quart. Rev. Biol. 32:
145, 1957.
6-22. Kulczynski, S. Peat bogs of Polesie. Mem. Acad. Sci. Cracovie,
Classe Sci. Math et Nat, B. No. 15, 1949.
6-23. Odum, E.P. and A.A. de la Cruz. Particulate Organic-Detritus in
a Georgia Salt Marsh-Estuarine Ecosystem. In: Estuaries, G.H.
Lauff (ed). Publ. 83, Amer. Assoc. Adv. Sci., Washington, D.C.,
147
-------
6-24.
6-25.
6-26.
6-27.
6-28.
6-29.
6-30.
6-31.
6-32.
Whigham, D.F. and R.L. Simpson. Ecological Studies of the
Hamilton Marshes: Progress Report for the Period June 1974 to
January 1975. In-house publication (mimeo), Department of
Biology, Rider College, Lawrenceville, N.J., 1975.
Bay, R.R. Ground Water and Vegetation in Two Peat Bogs in
Northern Minnesota. Ecology 48:308, 1967.
Odum, E.P. Fundamentals of Ecology.
Co., Philadelphia, Pa., 1971.
3rd Edition, W.B. Saunders
Tchobanoglous, G. and G. L. Culp. Wetland Systems for Wastewater
Treatment: An Engineering Assessment. In: Aquaculture Systems
for Wastewater Treatment - An Engineering Assessment, S.C. Reed
and R.K. Bastian (eds). EPA 430/9-80-007, 1980.
Sloey, W.E., F.L. Spangler and C.W. Fetter, Jr. Management of
Freshwater Westlands for Nutrient Assimilation, In: Freshwater
Wetlands: Ecological Processes and Management "Potential, R.E.
Good, D.F. Whigham and R.L. Simpson (eds). Academic Press, New
York, N.Y., 1978.
Lee, G.F., E.
Water Quality.
Madison, Wis.,
Bentley and R. Amundson. Effect of Marshes on
Water Chemistry Program, University of Wisconsin,
1969.
6-33.
6-34.
6-35.
Metcal f & Eddy, Inc. Wastewater Engineering: Treatment, Disposal
Reuse. 2nd Edition revised by G. Tchobanoglous. McGraw-Hill,
Inc., San Francisco, Ca., 1979.
TiTton, D.L. and R.H. KadTec. The Utilization of a Freshwater
Wetland for Nutrient Removal from Secondarily Treated Wastewater
Effluent. Jour. Environ. QuaT. 8(3):328, 1979.
Blutner, K. The Use-of'Wetlands for Treating Wastes -- Wisdom in
Diversity? In: Environmental Quality through Wetlands
Utilization. "Proceedings from a Symposium Sponsored by the
Coordinating Council on the Restoration of the Kissimmee River
Valley and Taylor Creek-Nubbin Slough Basin, Tallahassee-, Fla.,
February 29-March 2, 1978.
Vanoni, V.A. (ed). Sedimentation Engineering. American Society
of Civil Engineers, New York, N.Y., 1979.
Bennett, J.Pi and R;E. Rathbun; Reaeration in Open-Channel Flow.
U.S. Geological Survey, Professional Paper 737, 1972.
Tsiuoglow, E.C. and J.R. Wallace. Hydraulic Properties Related
to Steam Reaeration. Georgia Institute of Technology, Atlanta,
Ga., 1970.
148
-------
6-36. Holley, E.R. and K.K. Klintworth. Infl uence of Turbulence on
Surface Reaeration. Water Resources Center Report, University of
Illinois, Urbana, 111., September 1966.
6-37. Juliano, D.W. Reaeration Measurements in an Estuary. Jour. San.
Eng. Oiv., ASCE, December 1969.
6-38. Simpson, R.L. and D.F. Whigham. Seasonal Patterns of Nutrient
Movement in a Freshwater Tidal Marsh. In: Freshwater Wetlands:
Economic Processes and Management Potential, R.E. Good, D.F.
Whigham and R.L. Simpson (eds). Academic Press, New York, N.Y.,
1978.
6-39. Engler, R.M., D..A. Antie and W.H. Patrick, Jr. Effect of
Dissolved .Oxygen on Redox Potential and Nitrate Removal in
Flooded Swamp and Marsh Soils. Jour. Environ. Qual. 5(3):230,
1976.
6-40. Engler, R.M. and W.H. Patrick, Jr. Nitrate Removal from
Floodwater Overlying Flooded Soils .and Sediments. Jour. Environ.
Qual. 3(4):409, 1974.
6-41. Hickok, E.E., M.C. Hannaman and N.C. Wenck. Urban Runoff
Treatment Methods: Volume I - Non-Structural Wetland Treatment.
EPA-600/2-77-217, Cincinnati, Ohio, 1977.
6-42. Isirimah, N.O. and D.R. Keeney. Contribution of Developed and
Natural Marshland Soils to Surface and Subsurface Water Quality.
Technical Completion Report Project Number OWRR A-049-WIS, Water
Resources Center, University of Wisconsin, Madison, Wis., 1973.
6-43. Zoltek, J., Jr., S.E. Bayley et al. Removal of Nutrient from
Treated Municipal Wastewater by Freshwater Marshes, Progress
Reported to City of Clermont, Florida. September 1978.
6-44. Hall, F.R., R.J. Rutherford and G.L. Byers.. The Influence of a
New England Wetland on Water Quantity:and Quality. N.H. Project
No. A-015-NH, Water Resource Research Center, University of New
Hampshire, Durham, N-.'H., 1972.
6-45, DeJong, J. The Purification of Wastewater with the Aid of Rush or
Reed Ponds. In: Biological Control of Water Pollution, J.
Tourbier and R7W~. Pierson, Jr. (eds). University of Pennsylvania
Press, Philadelphia, Pa., 1976.
6-46. Whigham, D.F. and R.L. Simpson. The Potential Use of Freshwater
Tidal Marshes in the Management of Water Quality in the Delaware
River. In: Biological Control of Water Pollution, J. Tourbier
and R.W. Pierson, Jr. (eds). University of Pennsylvania Press,
Philadelphia, Pa., 1976.
149
-------
6-47. Boyt, -F.-L., S.E. Bayley and J. Zoltek, Jr. Removal of Nutrients
from Treated Municipal Wastewater by Wetland Vegetation. Jour.
Water Poll. Control Fed. 49(5):789, 1977.
6-48. Nicholls, K.H. and H.R. Mac Crimmon. Nutrients in Subsurface and
Runoff Waters of the Holland Marsh, Ontario. Jour. Environ.
Qual. 3(1):31, 1974.
6-49. Mu'droch, A. and J.A. Capobianco. Effects of Treated Effluent on
a Natural Marsh. Jour. Water Poll. Control Fed. 51(9):2243,
1979.
150
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SECTION 7
CASE STUDY REVIEW
Growing interest in the natural resource value of aquatic and
terrestrial ecosystems has spawned considerable research activity and
numerous symposia over the past 10 to 20 years. It has arisen out of
(a) concern over the susceptibility of such systems to land development
and pollution sources, and (b) scientific curiosity as to the role of
natural biological systems in assimilating various types of wastewater.
Literature related to wetland vegetative systems covers a wide range of
subjects. This includes (a) fundamental research regarding function,
biochemical processes, productivity, nutrient cycling and physical
relationships, as well as (b) a growing number of site-specific
investigations of pollution impacts and treatment capabilities. The
focus of this review is on the latter. Preceeding sections of this
report reference particular research efforts dealing with fundamental
processes and characteristics of wetland and upland vegetative systems.
The following review is intended to provide an understanding of how
different types of vegetative ecosystems in different geographical
regions have been observed to influence water quality and provide
treatment of point and nonpoint source wastewater flows. Processes,
relationships, function and operation of particular systems are treated
in greater depth in the analysis of vegetative and hydrologic practices
in Sections 5 and 6.
USE OF WETLANDS FOR HASTEHATER TREATMENT
Considerable attention has been devoted, recently., toward the use of
wetlands for wastewater treatment and nutrient assimilation,
particularly in North America and Europe [7-1, 7-2], In Europe,
research and applications involving wetlands and vegetative waste
treatment date back to the early work of Kathe Seidel and others at the
Max Planck Institute, in the early 1950's [7-3]. In the U.S., the past
ten years have seen promising results with experimental applications of
wastewater to peatlands in Michigan and Wisconsin [7-4, 7-5, 7-6, 7-7],
tidal marshes in Louisiana and New Jersey [7-8, 7-9], cattail marshes in
Wisconsin [7-10, 7-11, 7-12], cypress domes in Florida [7-13, 7-14,
7-15], and other natural and artificially constructed wetland systems in
various regions of the country [7-16, 7-17, 7-18, 7-19, 7-20]. A
discussion of the experience and findings of several major
151
-------
investigations With different types of wetlands are presented below. A
summary of observed pollutant removal efficiencies for most of the
referenced studies is provided in Table 31 following the narrative
discussion.
Northern Freshwater Marshes
o Brill ion, Wisconsin
Much work has been carried out in Wisconsin concerning the feasibility
of using natural and artificial marshes to provide secondary and
tertiary treatment of wastewaters. Investigations by Fetter et al.,
[7-10] on a natural cattail (Typha) marsh at the city of Brill ion
provide some of the most informative practical experience with
freshwater marshes subjected to long-standing wastewater discharges.
The 15-month study showed significant improvement in wastewater and
stream quality after passage through the marsh. In terms of critical
nutrients, a 51 percent reduction in concentration of nitrate.,and a 13
percent reduction for phosphorus were observed. Additionally, annual
net retention of phosphorus, due largely to precipitation into organic
sediments, was estimated to be perhaps as much as one-third of the
amount entering the marsh. Removal of oxygen-demanding substances and
suspended solids also showed very positive results. Despite the
apparent success with natural systems, the researchers favor efforts to
construct artificial marshes rather than discharging wastewaters to
natural wetlands.
o Hay River, fbrthwest Territories, Canada
An investigation similar to the Wisconsin study was conducted in the
farthwest Territories of Canada at a swampland, vegetated primarily with
sedges (.Carex) [7-21], The study area had been receiving discharges of
secondary effluent from the town of Hay River (population 3,000) for
many years. Substantial removal of wastewater pollutants was found to
occur in the swamp, to the extent that after passage through 60 percent
of the wetlands (3,600 m of channel), water quality was "nearly
indistinguishable" chemically and biologically from that of unaffected
waters in the vicinity. Pollutant removal efficiencies were generally
in excess of 90 percent during the summer flow period. Whether nutrient
removal is limited by rate of supply from the sewage, or by the rate of
uptake by macrophytes or sediments was not determined. Of ecological
significance, however, was evidence of reduced biological diversity over
40 percent of the wetland. Water quality was also measureably altered
within the swamp as a result of wastewater input to this area.
o Cootes Paradise, Ontario, Canada
In Ontario, Canada, a tidally affected lacustrine wetland was
"fnvestigated by Murdoch and Capobianco [7-22] to determine the effects
of long-term wastewater discharge. The study area (Cootes Paradise)
consisted of a 5.2 sq km wildlife sanctuary of which 1.7 sq km was open
water and the remainder, marsh areas and woodland. Marsh vegetation
152
-------
included many emergent and submerged plants, the major species being
Glyceria grandis, Myriophyllum, Ultricularia, Ceratophyl lum and Lemna.
In comparison with prior vegetative surveys, the area directly
downstream of the wastewater discharge showed an apparent decrease in
biological diversity with the loss of a stand of Typha sp. A pronounced
build-up of certain heavy metals, nutrients and organic carbon was also
found in the marsh soils of this area. Correspondingly higher levels of
heavy metals were also observed in the aquatic plants of this impacted
section of the wetland. The need to direct attention to the possibility
of heavy metal transfer to waterfowl and other parts of the food chain
was suggested by the investigators.
o Great Meadows National Wildlife Refuge, Massachusetts
In conjunction with feasibility studies of the overall concept of
wetland disposal of wastewater in Massachusetts, Yonika and Lowry [7-23]
investigated the effects of an existing wastewater discharge to the
Great Meadows National Wildlife Refuge in Concord. This freshwater
marsh wetland has been the recipient of sewage discharges since the
early 1900's. Concerns recently expressed about odor problems and
organic impacts on the wetland prompted the investigators to select
Great Meadows as a study site. Field investigations and evaluations
were conducted with respect to wetland hydrology, nutrient dynamics, and
water quality. Analyses were also conducted on sediment quality,
invertebrate populations and vegetative community. Results of the
testing program revealed:
(1) Great difficulty in attempts to model hydrology;
(2) Different renovating capabilities in different sections
of the marsh and, more significantly, in different
seasons of the year;
(3) Significant nutrient retention in the sediment;
(4) Dense luxuriant plant growth within a 60 to 75 foot
radius of the wastewater effluent pipe and evidence of a
"thermal plume" in winter;
(5) Predominance of pollution-tolerant tubificid worms within
250 feet of the discharge point;
(6) Conditions at the marsh outlet to the Concord River
similar to recovery zone downstream of a sewage
discharge.
Southern Freshwater Marshes
Several investigators have examined the usefulness and impacts of
wastewater disposal in freshwater marshes in the southeastern portion of
the U.S. The studies have met with variable results.
153
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o South Florida Everglades
'In an investigation of sawgrass wetlands in the South Florida
Everglades', Steward and Ornes [7-24], found that experimentally applied
levels of wastewater overloaded the marsh ecosystem with phosphorus in a
very short time (8 weeks). The low nutrient requirement of sawgrass was
felt to be a significant factor limiting the assimilative capacity in
this particular wetland situation. Changes in the composition of the
plant community indicated that undesirable effects on the unique
structure of the Everglades can result from the increased supply of
Eiutrients associated with wastewater discharges.
o Clermont, Florida
Other freshwater swamps and marsh areas were investigated in Florida
with more encouraging results. In 1977-78, a 10-month pilot study was
conducted for the city of Clermont, Florida, to determine the effect of
varied loadings of secondary wastewater effluent on the productivity,
and nitrogen and phosphorus budget of a freshwater marsh [7-17], The
study site was within a 32-ha marsh, composed primarily of emergent
aquatic macrophytes. Arrowhead, pickerel weed, panic grass and marsh
hibiscus were the dominant species. The study successfully demonstrated
the viability of utilizing the marsh as a tertiary system for upgrading
wastewater effluent quality. Specifically, the initial year of
operation showed major reductions in nitrogen and phosphorus, to
concentrations comparable with background levels. The apparent
reductions in phosphorus were due to accumulation and storage in the
soil complex, roots and dead standing matter. Studies of soils and
vegetation showed a possible higher rate of peat production and greater
plant uptake of phosphorus and nitrogen in areas receiving wastewater
discharges.
o Wild wood, Florida
In a University of Florida research study [7-16], a hardwood swamp which
h,ad been receiving wastewater effluent and surface runoff from the City
of Wildwood (population 2,500) for about 20 years was investigated.
Three contiguous wetland areas totaling about 200-ha were examined. The
wetland sequence consisted of a marsh community vegetated with duckweed,
cattail and, willow, followed by two hardwoo.d swamps. Water ,qual ity
studies showed reduction of nutrients through the wetlands to levels
equal to or less than those in the receiving waters of Lake Panosoffkee
and in an adjacent control swamp. High levels of nutrient removal were
associated with increased productivity of vegetation in the swamp.
Statistically significant growth rate increases were noted for cypress
a-nd ash. Unlike other wetland studies [7-25], nutrient buildup in
sediments was not found. The inflow of urban runoff was suspected of
causing disturbance of sediments in some areas of the wetland, resulting
in inconsistent ammonia nitrogen readings. Relatively low
concentrations of heavy metals in marsh and swamp waters reflected the
low levels discharged from the sewage treatment facility.
154
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o Cypress Wetlands, Florida
Cypress wetlands, commonly referred to as "domes", have been the subject
of considerable interest and investigation for wastewater disposal
feasibility [7-15]. The Center for Wetlands at the University of
Florida has been testing several cypress domes near Gainesville. The
results indicate rapid rate of nutrient uptake and little change in the
nutrient quality of underlying and downstream ground waters as a result
of wastewater application. Seasonal variations in rainfall make it
appropriate to adjust wastewater loading rates on a seasonal basis in
these wetlands. A comparison of vegetation in the cypress domes showed:
(1) Extensive growth of duckweed in the cypress domes
receiving wastewater;
(2) Varied aquatic plants in domes situated down-stream of
the domes receiving wastewater;
(3) Poor aquatic productivity in the natural domes unaffected
by wastewater application operations.
Northern Peatlands
The potential for treating wastewater flows in natural peatlands in
midwestern and northern portions of the U.S. has attracted the attention
of engineers and researchers. The most extensive work was that
performed by the University of Michigan Wetlands Ecosystem Research
Groups. The main focus of the research has been at Houghton Lake,
Michigan.
o Houghton Lake, Michigan
Study of the Houghton Lake peatland began as a pilot investigation to
determine the feasibility of utilizing the wetland for final tertiary
treatment and discharge of wastewater effluent from Lake, Denton and
Roscommon Townships [7-4, 7-5], The Tri-Township was in the process of
developing regional wastewater facility plans in the early 1970's when
the idea to make use of the wetland was first considered. Between 1972
and 1977, Kadlec and others conducted investigations of a 1700-ha
wetland site southwest of Houghton Lake, applying up to 380 m3/d of pond
stabilized wastewater. The .study site was comprised mainly of sedges
(Carex sp.), with scattered shrubs (Salix sp.) and herbs (Aster sp.).
Field studies included analysi s o f surface water quality, plant
productivity and nutrient status of plants and soils. Results indicated
that peatlands have potential as biological filters for removal of
certain nutrients. This was attributed to several factors:
(1) High nutrient adsorption capacity of organic litter and
peat soils;
(2) Slow subsurface movement of water;
155
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(3) High denitrification rates within the water-logged soils;
(4) Nutrient uptake by some plants.
In general, a high degree of contact between surface water, peat and the
litter layer has been found to be particularly Important to successful
wastewater treatment through peat wetlands.
At Houghto.n Lake, no adverse effects within the wetland as a result of
addition of nutrients and other wastewater constitutents were observed.
In fact, the added nutrients are considered to be beneficial to an
o.therwise nutrient-poor wetland [7-20]. As a result of these promising
pilot studies., approval was granted and construction began in 1977 on
one of the'ftrst full-scale operational wastewater facilities using the
concept of wetlands for final effluent polishing. The system is
currently operating as anticipated, with nutrient reductions of 90
percent within 30 meters of the discharge point.
0 Belialre, Michigan
Kadlec and Til ton [7-4, 7-6] have also monitored and evaluated the
discharge of wastewater effluent to a 18-ha, partially diked wetland in
Bellaire, Michigan. The wastewater is from the village of Bellaire
(population 1,000) which pro.duces an annual volume of approximately
114,000 m3 of sewage. The objective of discharging to the wetland is to
protect downstream receiving waters (Lake Bellaire) from excessive
nutrient additions. The sewage receives secondary (lagoon) treatment
prior to discharge. Releases to the wetland occur from May to November,
with holding ponds providing overwinter storage of-effluent. The
wetland is distinguished from the toughton Lake facility by the closed
canopy of coniferous trees at the BeTlaire site. Despite this
vegetat.ional dissimilarity, nutrient removals (80 to 90 percent) were
found to be as efficient as at Houghton Lake.
Tidal Wetlands ;
in the la.te 1960's, Grant and Patrick [7^-26] undertook a field
investigation of the Tinicum Marsh in Pennsylvania to assess the health
and function of the tidal wetland :ecosystem in relation to existing
wastewater discharges. Three sewage treatment plants discharging into
the marsh were kno,wn to be contributing to high organic loadings to the
wetland. The main focus of the investigation was on nutrient
assimilation, reoxygenation of surface waters and wetland productivity.
The chemical analyses and biological field studies confirmed damage to
the marsh from the wastewater loadings. In particular, severe bacterial
contamination, low oxygen and high nutrient lev-el s were observed.
Decreased species, diversity in the Tinicum Marsh in comparison to a
nearby undisturbed marsh provided evidence of biological damage.
156
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Because of tidal flow and varying volumes of sewage discharges, the
researchers found it difficult to assess the distribution of organic
loads and the exact pollutant reduction efficiency of the wetland. It
was observed, however, that significant reductions in BOD, phosphate,
ammonium and nitrate occurred as a result of the tidal excursion of the
river water over the marshland, in the time interval of about two to
five hours. Although field data showed inconsistencies, probably due to
the irregular flow pattern and pollution load mentioned previously, it
was evident from the study that these particular marshlands make a
significant water quality contribution through reduction of nutrient
loads and increases in oxygen content.
Artifical Wetlands
o Germany and Holland
The creation of artificial wetlands for treatment of wa-stewaters has
been investigated for both small and large scale applications in Europe
and the U.S. with different types of vegetation and substrate. Some of
the most extensive information has been compiled by Kathe Seidel and
others at the Max Planck Institute in Germany [7-3], Here, the
functions and role of higher aquatic plants in wastewater purification
have been investigated. The work has resulted in the development of a
patented wastewater process, the Max Planck Institute (MPI) system,
which relies on cultures of selected plant.species. The system consists
of two parts:
(1) Sludge retention and decomposition, and reduction of
certain bacteria counts, by beds of Phragmites plants;
(2) Extensive elimination of dissolved organic and inorganic
substances and of bacteria by means of a cascade
plantation consisting of Schoenoplectus lacustus or other
appropriate plants.
The system has potential for treating small wasteflows, such as those
generated at campgrounds, schools, farms, hotels, etc. To date, it has
been successfully employed at several locations in the Netherlands.
Joost De Jong [7-27] reports on the application of an artificial rush
pond at a seasonal campground in Holland. Several geometrical layouts
were examined, prior to choosing long ditches that facilitated
mechanical maintenance. The system demonstrated very good removal
efficiency for BOD, nitrogen, phosphorus and bacteria, using raw sewage
influent.
The main pollutant removal functions were related to
infiltration-percolation, sedimentation, and plant uptake. Removal of
all pollutants was found to vary with detention time, with best results
occurring after a minimum of 10 days retention. Decreases in nutrient
removal toward the end of the season (August) were attributed to an
overloading of nitrogen and phosphorus by this point.
157
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o Long Island, New York
In the U.S., artificial marsh systems were constructed at the Bropkhaven
National .Laboratory in Long Island,- New York [7-1^8, .7-28,, 7-29, 7-30,
7-31]. two,- closed systems have been -under study since 1973:' (a) a
marsh/pond system and :(b) a meadow/marsh/pond system. The component
parts were as follows:
(1) Meadows were backfilled -with -15 to:20 cm.of sand loam and
planted with reed- canarygrass; these we-re-eventually
suppVemented-with volunteer- .grasses and. weeds;
(2). Marshes were .backfilled with- 10 to' 15 cm of mulch and
planted principally with cattails;.,.
(3) An 80 m^ pond served to stabi.l ize:..;effl:uent: from the
marshes and meadows. It ts up ported a healthy groStfth- of
duckweed.. .... .. -.. ....' .''; ; ,'''-., -; ' ;" -; ..-' .."-.'.. "
Both systems have- demonstrated the ability to renovate applied sewage
and septage:mixtures of up to 80 m^/d. Measurement .to date of a IV. ..-key-
water quality parameters indicates that both:-systems produce water
suitable-for ground-water recharge., over-or through vegetated soil,
without posing public health hazards. The investigators are strongly in
favor of using artificial marsh systems rather than -natural wetlands for
wastewater treatment- purposes [7-28];
The creation of wetlands for wastewater treatment purposes is of growing
interest because .of the .multiple .benefits that may be realized. Two
particular systems- currently .in/operation illustrate .this potential and
are discussed below.
California';
The los'sv over- the"yearsv of brackish -an^d,-fresh water marshes1 and
wertland'S -in the-*Sa-n< -Francisco Ba-y Area-,, to .ur.ba-n .and agri-cultura.!
develo pment has rec-en'tly given ri se .to publ i c interest in the
pr-eservatxion ;and- restoration- of marsh 1 an'ds. The objective ;,has been
realized in the -bayside, city of'Martinez, where secondary^treated
eff 1 uent .has been, used .to- create a freshwater -ma-cs-h [7-19, 7-3,2.]. In
meeting'-wast-e discharge .requirements and- wetland objectives, the project
has gained substantial: public support. The proj.ect has provided the
folio wingi.
(1) A balanced and healthy wetland :ecosystem-created through
the reuse of treated .wastewater;
(2) Newly established wetland-, habitat for numerous species of
animals, birds and aquatic invertebrates;
(3) Consistent nitrate removal and sea-sonal BOD and suspended
solids removal;
158.
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(4) Increasing educational and recreational usage;
(5) The impetus for the development of similar pilot-scale
projects in the San Francisco Bay Area and other areas in
California [7-33, 7-34, 7-35].
o Vermontvine, Michigan
In Vermontvil le, Michigan, a seepage wetland system was constructed to
provide final treatment (phosphorus removal) for pond-stabilized
wastewater [7-20, 7-36, 7-37]. The system is operated in a manner
similar to flood irrigation, with treatment provided by nutrient uptake
in upland grasses, and soil-water interaction as wastewater seeps
downward and laterally from the irrigation fields. The grasses are
harvested periodically. The irrigated land has become a marsh area,
inhabited by a wide variety of volunteer wetland plant species,
including cattail, willow, duckweed, grass and goldenrod. During the
irrigation season, areas of standing water support a variety of
waterfowl and other wildlife. The primary treatment objective of
phosphorus removal is obtained for most of the year. The exception is
in the late spring and summer irrigation season when the wetland
actually increases phosphorus amounts above those of the applied
wastewater. This is in part due to inputs of rainfall which cause
wastewater to pass over the surface of the marsh, .bypassing seepage
routes. These results are in agreement with other wetland studies which
suggest that the flow-through process without substantial contact and
filtration by native soils might prove unsatisfactory for removal of
phosphorus.
Aquatic Plant Systems - Water Hyacinth
The use of water hyacinth and other free floating plants for wastewater
treatment is generally not considered a wetland system, but rather an
aquatic plant system. Much work on these aquaculture treatment systems
has been done recently in the southern areas of the U.S. The reader is
referred to several case studies [7-38, 7-39, 7-40] presenting
information and a general analysis of wastewater treatment by means of
water hyacinth and duckweed. Some of the most extensive work on the
subject has been reported by Dinges [7-41, 7-42, 7-43] for the treatment
at the Williamson Creek Facility in Austin, Texas, and by Wolverton et
al. , [7-44, 7-45, 7-46] for experimental work at the National Space
Technology Laboratories in Bay St. Louis, Mississippi.
The research found that water hyacinth systems are capable of removing
high levels of BOD, suspended solids, metals and nitrogen, as well as
significant uptake of refractory trace organics [7-38]. Phosphorus
removal is limited to plant needs and normally will attain 50 to 70
percent of the influent amount only when careful management and regular
biomass harvesting is carried out. In addition to direct plant uptake,
159
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TABLE 31, OBSERVED POLLUTANT REMOVAL EFFECTIVENESS OF WETLAND-WASTEWATER TREATMENT SYSTEMS
System/location
Brillon, Wisconsin
(Existing discharges)
. i
-------
TABLE 31. (continued)
System/location
Cootes Paradise,
Ontario* Canada
(continued)
South Florida
Everglades
(Pilot study)
City of Clermont.
Florida
(Pilot study)
City of Mlldwood.
Florida
(existing discharge)
Wetland Hydraulic/
type hydrologic factors
wastewater 30-40K of stream-
' flow
detention time variable.
from 2.16 days (spring)
to 11.8 days (summer)
Freshwater Equivalent loading of
marsh 2.5 cm/wk/ha
(sawgrass)
Freshwater ?
marsh Four 200 in plots
Loading rates of 1 .3.
3.8 and 10.2 cm/wk
Hardwood 202 ha swamp area
swamp
672 ha watershed
S70 m3/d wastewater
input
Appl icat ion
concentration
Total P 4.73 mg/l
Data not available.
Total N 0,11 ,56 and
112 kg/ha
(one-time closing)
Total P 10 rag/1
(2.5 kg/(ha)(wk))
Total N 10', month avH.
of 1.14 kg/(ha)(d)
Total P 10', month ave.
1.19 kg/(ha)(d)
Total N 15.3 mg/l
Total P 6.4 mg/l
Wastewater
Cu - 0.02 inij/l
Fe - 0.17 mg/l
Hg - 4.1 mg/l
Pb - 0.03 mg/l
Zn - 0.048 mg/l
Urban runoff
Cu - 0.01 mg/l
Fe - 0.11 imj/l
Mg - 3.2'mg/l
Pb - 0.02 m
-------
TABLE 31. (continued)
System/location
Houghton Lake ,
Michigan
(Pilot studies
for new full-
scaVe system)
Bellalre, Michigan
(New Discharge)
Wetland
type
Peat land
Freshwater
marsh
(with forest
Hydraulic/
hydrologic factors
17QO ha wetland
3.9 cm/Hk to 6.5 ha site
(hyd. loading)
20.45 ha wetland
May-N6v. loading of
118.740-134,207 mj
Application
concentration
NH.-N 11). (i nig/1
(N02»NO,)-N .3i mo/1
* J
Total P ,41 mg/1
(NH4+N03)-N 4.95 mg/ 1
Total P 3.48 mg/1
Removal
efficiency
711
99%
951
911
971
Comments and reference
o Nutrient immobil ization due
to devitrification and
sorption by peat.
o P reductions varied with
water depth (6-30 cm) and
seasonally. Greatest release
during late winter- and early
spring.
(7-4. 7-5)
0 Monthly removal rates varied
in response to hydrologic con-
ditions, plant growth, and tem-
perature.
ov
ro
canopy)'
Water samples taken during late
winter and early spring Indi-
cate a release of P equal to
1.02% of the total added '
over the period March-
November.
(7-4. 7-6)
Great Meadows
National Wildlife
Refuge
(Existing Discharge)
Freshwater hydraulic loadings -
marsh .009-.034 mj/s
(deep water) 115 ha watershed
19 ha wetland
yearly average
TKN 10.0 rog/l
NH/i-N 8.0 mg/1
N03
Total I'
Ortho P
3.1 mg/1
annual average
35i
5Bi
20'i
2.1 mg/1
1.6 mg/1
47%
19.'.
o Extreme seasonal variations
noted. Highest removal in
Spring and early summer **
growing season. Denitrifi- .
cation most significant factor.
Low removal rates and release
during fall-midwinter (TKN),
and winter-early spring
(N03-N).
o Significant seasonal fluc-
tuations in P removal from
85.71 in early spring to
net increase of 72.8X in
mid-winter. Variations
judged to be related to sedi-
ntnl-vegetal ion interactions
and marsh hydrology.
o Seasonal variations evident
with best renoval during Juiie-
Septeiiiber. Intake rates of
6 lbs/(acre)(day).
(continued)
-------
TABLE 31. (continued)
System/ location
Great Meadows
(continued)
Brookhaven National
Laboratory, New
York
(Artificial system)
Martinez,
California
(New full-scale
system)
Wetland Hydraulic/
type hydrologic factors
freshwater sewage loading of
marsh-meadow HO cir/d
pond systems
60-80% recycled within
system
.2 and .4 ha systems
pond - 1.5.H1 deep with
946 nr capacity
meadows - 3% slope
marshes .5- 1m depth
Artificial 6.1 ha wetlands plot
marsh
£3% open water
(deep water)
37% emergent vegetation
461)7 in3 capacity
4.8 days retention
tine at 6056 a? /it
current retention time
about 10 days
current loading is
2839 mj/d
Application
concentration
BOD
SS - data
Total N
NH3-N
. Kjeldahl-N
(N02tN03)-
Total P
P04-P
Cr
Cu
Fe
Mg
Zn .
OOD5
SS
NH3-N
N03-N
N02-N
Total or-
ganic N
38.2 mg/1
not available
25.2 rag/1 ''
B.4 mg/1
19.7 mg/1 ;'
N 5.5 mg/1
7.2 mg/1
4. 8 mg/1 :
.05 iiig/) '/
0.7 mg/1
3.6 mg/1
4.3 mg/1 ;.
1 . 3 nig/ 1 '
170 mg/1
353 mg/1
7.0 mg/1
6.1 mg/1
0.38 mg/1
4.1 mg/1
Removal
efficiency
67% o
overall de-
crease
. 79" o
86'.. .
em
73A t
77*
77%
60X '
94'. ''
58%:
23^ '
85%"
88-92%
91.5
Averages (1975) o
Wl
56?. ;
Overall increase
12;
l.ui.Mt-nU .~-.il' rif'.'reiice
Considerable and inconsistent
variations observed, few
correlations found between
SS changes and seasons, hy-
draulic characteristics or
biological influences.
(7-23)
Reductions are for the total
system (meadOH/marsh/pond) .
The removal abilities of the
Individual components have
not been analyzed.
Meadow-marsh-pond system some-
what more effective than marsh-
pond system.
(7-30, 7-31)
Marsh purposely managed to
enhance wildlife rather than
to optimize pollutant uptake.
(continued)
-------
TABLE 31. (continued)
Wetland
System/ location type
Martinez, California
(continued)
Vermontville. Michigan Artificial
seepage
(tew system) wetland
Williamson Creek Hyacinth
Treatment Plant, Texas pond
(Pilot system)
National Space Tech- Hyacinth
noloyy laboratories pond
(Experimental system)
Hydraulic/
hydrologic factors
4.6 ha diked irrigation
fields
94,661 m3 of effluent.
June-October
0.0585 ha pond
1.0 m depth
1.860 m3/hahyd. loading
5.3 days residence time
2 ha pond
1.22 in depth
240 in3/ha hydraulic
loading
54 days residence time
Application
concentration
PO,,-P 10.4 mg/1
BOO 19 mg/1
SS 22 mg/1
Data on N not available
Total P 1.8 mg/1
(wastewater)
Total P 2.1 mg/1
(combined wastewater
and wetland waters)
Total N 4.3 mg/1
NH3-N 2.1 mg/1
P04.-P 15.4 mg/1
Data not available on
Iteavy metals
BOD 19 mg/1
SS 46 mg/1
Total H 12.0 mg/1
Total P 3.7 mg/1
BOD 110 mg/1
SS 97 mg/1
Removal
efficiency
13%
36.8%
not available
601 of NO 3
971
121
71 1
31% annual
Significant
plant accumula-
tion of Cu, Cr,
Fe, Mg, Hn. HI.
Pb, Zn
81.7%
84.5%
71.7%
57%
94.7
*
89.7%
Comments and reference ..'
o Best phosphate removal
during sunnier months.
o High BOD readings in sunnier
months due to algae.
o Heasureably lower values
during cooler months but
significant increase during
summer algal blooms. (7-10, 7-32)
o Reduction occurs through
denltrlflcation 1n the shallow
wetland soil.
0 P removal occurs through soil
adsorption of wasteuater prior
to encountering ground water.
95% occurs in upper 3 feet
of wetland soil.
(7-20. 7-36, 7-37)
o Significant nitrogen uptake
obtained in both summer and
winter.
o Removal of P restricted to
plant growth season.
o Uptake directly from influent.
and ponded water
o Accomplished primarily through
reduction of suspended par-
ticulate matter capable of
producing effluent BOD of
less than 10 mg/1.
(7-40. 7-41. 7-42. 7-43)
o Regular harvesting of hyacinth
needed to maintain effective
nutrient removal.
0 Loaded at 2(> (-.() HOD (ha) (day)
without development of odor
problems.
(7-3H, 7-44)
-------
factors which contribute to the wastewater renovating capabilities are
(a) an active mass of organisms supported by the root system, and (b)
shading of the water surface by plant leaves, limiting light penetration
and algae growth [7-38].
LAND TREATMENT OF HASTEHATER
Land treatment of municipal wastewaters has been one of the most
extensively studied aspects of sanitary engineering during the past 10
years. The capacity of the soil-vegetation complex for wastewater
renovation has long been recognized. The current incentive to continue
investigations and expand the usage of land disposal practices can be
attributed, in part, to the enactment of the Federal Water Pollution
Control Act Amendments of 1972, which clearly focus on reduction of
surface water discharge of pollutants, and encourage consideration of
land treatment as an alternative treatment method in wastewater
facilities plans.
A vast amount of literature Is-available .on various aspects of planning
and feasibility investigations, treatment mechanisms and performance,
and design criteria and procedures. The most thorough treatment of the
subject is provided in the "Process Design Manual for Land Treatment of
Municipal. Wastewater" [7-48] .sponsored by,.the USE PA, US tarps-. of, Eng.
and USDA in 1977. An exhaustive review.of .practice and literature
pertaining to land disposal methods is provided in that document. In
addition, an update of this manual is currently under preparation.
WETLANDS TREATMENT OF SURFACE RUNOFF
Field studies and research concerning the use of wetlands for treatment
of surface runoff flows have been extremely limited. The recent interest
that has developed is, primarily, a result of the search for innovative
methods for controlling nonpoint surface runoff pollutants.
Case Studies
Several major investigations which provide information orr the
effectiveness of wetlands as stormwater treatment systems are summarized
here. They represent a wide diversity of wetlands types and
geographical regions. Included are northern peatlands, cypress
wetlands, a brackish marsh, high altitude meadows and wetlands detention
basins. Brief descriptions of the various wetland-stormwater systems
which were the subject of these investigations are provided below.
o Wayzata Wetland, Minnesota
The Wayzata Wetland in Wayzata, Minnesota was recently investigated by
Hickok et al., [7-49], to evaluate the interactions of stormwater runoff
in a wetland area and determine the potential usefulness of such areas
in management of water quality. The study site was a 3.06 ha peat
165
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wetland, located in the center of the City of Wayzata (population
4,500), on the outskirts of the Minneapolis-St. Paul metropolitan area.
The contributing watershed (26.3 ha) consisted of mixed urban, sparsely
developed, and open wooded land uses. Inflow to the wetland consisted
of direct precipitation (35 percent), surface runoff (47 percent) and
ground-water inflow (18 percent). Water losses were through
evapotranspiration (25 percent) and surface discharge (75 percent).
o Palo Alto Marsh/Flood Basin, California
The Palo Alto Flood Basin is a marsh area adjacent to San Francisco Bay,
which serves to impound stortnwater runoff and provide flood protection
to the low-lying areas of the city of Palo Alto. Constructed in the
mid-1950's,. the basin is formed by a series of levees and tide gates
surrounding a pre-existing bayside marsh area. It receives drainage
from a highly urbanized watershed of about 72 sq km. The marsh contains
a mixture of salt and freshwater vegetation and.upland grasses. The
flood basin has been the subject of a recently concluded EPA-sponsored
investigation intended to evaluate changes in surface runoff quality as
a result of ponding and biological activity in the marsh [7-50].
o Lake Tahoe Meadowlands, California
Morris et al., [7-51] recently conducted a one-year field investigation
of the effectiveness of natural marsh and meadowlands to provide
treatment of surface runoff in the Lake Tahoe Basin. Seven systems
consisting of four streams and. three .tributary drainage areas were
investigated.. The contributing watersheds consisted of a mix of urban,
rural residential, pasture and forested.lands. The primary focus of the
study was on nutrient and sediment loadings associated with land
development, road construction arid other soil disturbance activities.
o Cypress StanoM)rlando, Florida.
In connection with Section 208 water quality planning studies for Orange
County, Florida, natural treatment of surface runoff through a cypress
stand was investigated [7-52, 7-54]. The wetland study site is located
at the University of Central Florida and serves a drainage area of 9.76
ha, of which 67 percent is an impervious area. The wetland is
characterized by marsh vegetation and small cypress at the exterior, and.
mature cypress with intermittent p&nds and sloughs in the interior.
Stormwater from the campus grounds is channeled into the cypress stand
where it follows a circuitous, slow-moving path, leaving the wetland by
means of surface outflow, evapotranspiration or soil infiltration.
Analysis o"f treatment effectiveness focused in this study on BOD,
suspended solids, nitrogen and phosphorous.
166
-------
o Montgomery Mall Lake, Maryland
Among the many stormwater detention and control facilities constructed
in Montgomery County, Maryland since the early 1970's is the Montgomery
Mall Lake [7-53, 7-54]. This is an offsite storage/detention pond
serving a 60 ha watershed. Included in the drainage area are a large
shopping mall, several apartment complexes, townhouses, a major highway
and several secondary roads. The pond is used to limit peak flows and
to reduce surface runoff pollutants. The pond has a 2.4 ha permanent
pool with 45,600 nr of dead storage capacity. The pond is designed to
control an inflow of .62 m-fys and to release the volume at about .06
m3/s. Grasses and wetland vegetation line the edge of the pond.
Pollutant removal efficiencies of the detention facilities have been
reported by McCuen [7-54].
Summary of Surface Runoff Treatment
Monitoring of the various wetland-stormwater systems includes a broad
'assortment of measurements related to:
o hydrology;
o climate;
o vegetation;
o water quality;
o soils.
A summary of pollutant removal determinations for principal stormwater
constituent is provided in Table 32 for each of the investigations
described above. The following points should be kept in mind with
regard to these data:
(1) Great disimilarities exist between the various systems
studied in terms of wetland and surface runoff
characteristics and monitoring procedures;
(2) Because the sampling periods upon which the data are
based are generally very short (in most cases no more
than one year), the statistics are not very reliable;.
(3) Numerous sampling difficulties and complications in
determining hydrologic components of some of the systems
further reduce the reliability of the computed pollutant
mass balances.
Despite these qualifications, certain conclusions can be drawn from
these results:
(1) Wide disparity exists in nonpoint source pollution
removal capacities of wetlands, particularly with regard
to nutrients;
167
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TABLE 32. OBSERVED POLLUTANT REMOVAL EFFECTIVENESS OF WETLAND-STORMWATER TREATMENT SYSTEMS
System/location
Mayzata,
Minnesota
(Existing runoff
situation)
_. Palo Alto,
crt Cal i fornla
CO
(Flood control
basin)
lake Tahoe,
California
(Natural
system)
Wetland Hydraulic/
type hydrologic factors
Peatland 28.3 ha watershed
' 2.8 ha wetland area
Inputs:
Precip. - 2.38 ha-m
G.W. - 1.20 ha-rn
Runoff - 3:19 ha -m
Brackish 240 ha marsh
tidal 72 Km2 watershed
marsh 224 ,000 oj dead
storage
Mainly channelized flow,
high marsh areas innun-
dated Infrequently.
High Several sites Int'es-
altitude tigated with water-
meadows sheds of several
hundred to 14,350 ha.
Wetland slopes of
2-74.
Application
concentrat ion
Removal
efficiency
(Annual average)
NH3-N
Total
SS
Cd
Cu
Pb .
la
Total
Total
SS
VSS
BOD
Cd
Cu
Nl
Pb
NH,-N
J
NO,-N
J
TKN
Total
SS
3.94 mg/1
P .92 mg/1
701 nig/1
.4-1.4ug/l
|J J'
12-19 pg/1
26-7' ug/1
,
10-15 ,jg/l
(Average)
N 3.67 mg/1
P 0.36 mg/1
290 mg/1
62.9 mg/1
12.2 mg/1
0.05 mg/1
< 0.01 mg/1
0.07 mg/1
0.16 mq/l
.02-. 44 mg/1
.02-. 57 mg/1
.2-6.6 mg/1
P .Olli-l .9 mg/1
1-2,978 mg/1
Net increase
784
944
25-80%
73-83%
90-97%
78-864
37%
Net increase
87%
854
544
NA
NA
NA
NA
Up to 67%
Up to 964
Up to 764
Up to 93%
Up to 994
o Nutrient discharge from wetlands
0 P seems to be limiting plant
nutrient. Hicrobial activity
appears to be initial and
most important mechanism for
P removal
o Heavy metal Inflow concentrations
and removal efficiencies varied
according to contributing land
uses. Greatest reduction values
for commercial area runoff.
(7-49)
o Inflow/outflow pollutant rela-
tionships extremely variable
from storm to storm.
o Outflow SS exhibited less
variability than inflow levels.
Because of hydraulics, very
' little solids deposition ap-
pears to occur in high marsh
areas.
o Heavy metal Inflow and outflow
levels were at limits of de-
tectablllty.
0 Consistent decrease of Pb
(7-50)
o Extreme variability in nutrient
removal . Many instances of
Increase through wetland. Host
significant reductions during
storm episodes .
o TKN released from wetland systems
during spring snowmelt runoff.
removal greatly enhanced by
sheet flow conditions.
(7-51)
-------
TABLE 32. (continued)
System/location
University of
Central Florida
Montgomery Co.,
Maryland
CTl
10
Wetland Hydraulic/
type hydrologic factors
Cypress 9.76 ha watershed, with
stand 67% Impervious area.
Wetland 60 ha watershed
detention 2.4 ha permanent pond
basin with 45,600 m3 dead
storage capacity
Depth - .9 to 4 m
22 hr. detention time
8 peak inflow rate of
0.62 mj/s.
Application . *
concentration
Total
Total
SS
8°°5
NH,'-N
j
Total
Ortho
BOD5
Cd
Fe
Pb
Zn
N «
P 8
22,580
145
3
P 0.
P 0.
5,
0.
4.
0,
0.
Kg/y. ..
KO/V. .'
K<)/yr.
kg/hr.
g/s '
3 0/s '
,13 g/s
,2 g/s
,18 rog/s '
.7 mg/s
.18 mg/s '
,23 mg/s
Removal
efficiency
951 .
97*
99'X
89i
99S
99% '
9»
9>i
98%
96%
96i
99%
Comments and reference
o Slow moving, circuitous flow
allows particulate matter to
settle and accumulate rapidly.
(7-52. 7-53)
o Large permanent pond volume
Is key factor in high pollu-
tant removal efficiencies.
(7-53. 7-54)
-------
(2) Greatest consistency in pollutant reduction appears to be
for BOD, suspended solids and heavy metals;
(3) -Seasonal .factors can have a major influence on pollutant
removal capabilities of certain wetlands.
In addition to the tabulated data, the various investigations produced a
number of findings and observations which provide greater insight into
stormwater treatment effectiveness of wetland systems.
The nature of the flow through wetlands is considered to be a critical
factor affecting treatment removal. In the Lake Tahoe study, the extent
to which runoff followed a sheet flow pattern was found by the
investigators to be the most significant factor distinguishing pollutant
removal effectiveness at different meadowland sites [7-51], The
slow-moving, circuitous flow'paths through the cypress stands in Florida
are, likewise, a major contributing factor to high levels of pollutant
reduction [7-53]. In. the Pa.lo Alto study, widespread flooding did not
occur during the investigation* Rather, the flow remained confined to
the well-defined channels traversing the marsh [7-50], The resultant
effect on pollutant removal is unknown but probably of significance.
The influence of the seasons ;and individual storm'episodes was observed
in these investigations. Nutrient discharges in particular were related
to the seasons in the Wayzata wetlands [7-49]. The flushing and
l(eaching: effects of spring snow melt appeared to be the cause for higher
total Kjeldahl nitrogen and organic carbon discharges in the Lake Tahoe
jneadowlaTids [7^41]. In terms of treatment, Morris et al., [7-51] found
..'the most dramatic nutrient and'sediment reductions in effective meadow
'systems to be associated with individual storm episodes.
In the Wayzata study, microbial activity in the wetlands appeared to be
the. initial and most impqrtant mechanism for removing phosphorus from
the soil -W^ter solution [7-49], 'Under submerged, anaerobic conditions,
this activity, was found to decrease dramatically, suggesting a similar
decrease in phosphorous removal capability.
In the Lake Tahoe. investigation, the. extreme variability observed, in
terms of.nutrient removal , strongly points to the need to carefully
examine each individual wetland,system, prior to predicting its
usefulness in surface runoff management. In addition to flow regime,
increasing slope of the wetland and extensive grazing appeared to have
negative impacts on treatment effectiveness. The presence of beaver
dams on the other hand seemed to have a' beneficial effect [7-51],
studies of wetland soils and vegetation provided interesting results in
the Palo Alto Marsh'investigation. Lead, zinc and copper concentrations
in surface soils were found to be directly proportional to pH [7-50].
170
-------
With changes in pH from 5 to 6, adsorption of lead, zinc and copper to
soil surfaces was found to increase. Pickleweed, which predominates in
the lower-elevation areas of the marsh, demonstrated the ability to
extract heavy metals from the flood basin to a greater extent than the
mixed marsh vegetation or upland grasses. In particular, aboveground
plant tissue was found to accumulate zinc and cadmium at significant
levels beyond soil and stormwater concentrations.
Extensive assessment of associated environmental impacts was not
undertaken as part of these investigations. Limited field evaluation of
biological (wildlife and vegetation) impacts revealed no adverse effects
in either the Wayzata Wetlands or Palo Alto Marsh studies [7-49, 7-50].
The concentrations of heavy metals in soils did not appear to have
substantial effects on plant conditions in the Palo Alto Marsh [7-50].
UPLAND RETENTION AND TREATMENT OF SURFACE RUNOFF
The practices of utilizing vegetated detention basins, grassed drainage
swales .a.nd other upland areas for the control of stormwater runoff have
gained wide acceptance and attracted considerable research attention in
recent years [7-55].. Most of the literature addresses hydrologic and
operational aspects of such practices. Poetner [7-56] prepared a
comprehensive, .review:of stormwater. detention -pratt/ices in which numerous
case studies are used to illustrate various, design approaches and
state-of-the-art technology. Additionally, broad coverage is given to
legal, environmental, economic, and operation and maintenance aspects.
The potential role of detention facilities for treatment purposes is
addressed primarily, in terms of erosion and sediment control. A number
of others have devoted research to hydrologic analysis and optimization
of detention facilities [7-57, 7-58, 7-59],
Very little information has been developed with respect to the
stormwater pollutant removal capabilities of grassed waterways and other
upland retention and detention facilities. As a consequence, concepts
and findings related to land treatment of wastewater have been used to
evaluate expected treatment.effectiveness and design requirements
[7-60].
A number of recent 208 water quality management studies have examined
various types of upland detention storage .and runoff control strategies
for management of nonpoiht source pollutants. In one such study,
Biggers et al., [7-61] used simulation techniques to. evaluate projected
pollutant removal effectiveness of stormwater retention and detention
practices. Pollutant removal rates were approximated based upon those
reported in the literature for land treatment operations relying upon
rapid infiltration and high-rate irrigation techniques. The simulation
exercise yielded ranges of expected annual pollutant reductions for
different contributing land uses as shown Table 33.
171
-------
TABLE 33. SIMULATED ANNUAL POLLUTANT REMOVAL RATES FOR
DETENTION BASIN AND ON-SITE RETENTION/DETENTION CONTROLS3
Removal of pollutant, %
Management practice Total P Total N BOD Lead Zinc Sediment
Detention basin 33-48 21-36 31-47 82-88 47-53 88-94
On-site retention/
detention controls 52-68 37-45 73-90 86-95 85-95 89-99
a. Source: reference 7-61. .
The results also pointed to hydrologio design modifications that could
s-igni ficantly improve pollutant removal in detention basins which have
traditionally been designed as peak flow attenuation facilities. Others
have also identified the need to integrate flood,, erosion arid pollution
control technologies to benefit from the multiple uses of stormwater
detention practices [7-62, 7-63J.
Two recent field studies provided useful data and evidence of surface
runoff pollutant control, achieved through the application of upland
vegetative practices.
'Retention/Detention Controls
In Orange Cbunty, Florida, various nonstructural and low-technology
facilities have been installed and tested for controlling and treating
stormwater runoff near its source [7-52, 7-53], The individual unit
facilities include: . .
(1) Percolation facilities, which provide for infiltration,
detention, and overland treatment of runoff;
(2) Underdrains, providing for collection and drainage of
stormwater after passage through permeable surface soils;
(3) Residential swales, providing for on-site percolation of
ponded stormwater in grassed depressions;
(4) Detention/sedimentation basins, equipped with debris
traps, and baffle arrangements.
The major stormwater pollutants of concern in Orange County have been
identified as BOD, suspended solids, total nitrogen and total
phosphorus. The implemented control measures have demonstrated their
172
-------
effectiveness in reducing the loadings of these pollutants to receiving
waters. The combined effect of these practices has not been determined,
although it is expected to be substantial. Table 34 provides the annual
pollutant loadings and removal efficiencies for these various management
practices. The high removal rates reflect the combined processes of
detention, percolation and soil adsorption ,and filtration. The
actual role of vegetation is not known.
Grassed Waterways
The use of grassed waterways has been, primarily, in conjunction with
agricultural practices. Much of the associated research and development
work has focused on hydraulic design, channel stability and erosion
control functions [7-64, 7-65]. Specifications for design, construction
and maintenance are included in several publications issued by the USDA
Soil Conservation Service [7-65], The emerging concern regarding use
and impacts of agricultural chemicals has given rise to investigations
into pollutant removal capabilities of vegetated areas adjacent to
cropland. One such study was conducted by Asmussen et al., [7-66] at
Tifton, Georgia; The objective of this .particular study was to evaluate
the capacity of a grassed waterway for removing the herbicide 2.,4-D from
agricultural runoff. '
The waterway studied was 24.4 m long with a 2 percent slope, and was
planted with bermudagrass , bahiagrass and other common grasses.
Simulated rainfall (25.4 cm/hr) was used to generate runoff under dry
and wet antecedent soil conditions in both the cropped area and the
waterway. Sampling along the waterway showed substantial reduction in
sediment and herbicide loadings as evidenced by the data in. Table 35.
TABLE 35. REDUCTION IN WATER,
AND 2,4-D IN THE V
(TIFTON, GEORGIA)
SEDIMENT AND 2,4-D IN THE WATERWAY3
Reduction, %
Dry condition wet condition
Runoff (water) 50 .2
Sediment 98 94
2,4-D in water phase 71 69
2,4-D in sediment phase >99 >99
Total 2,4-D , 72 69
a. Source: reference 7-66.
173
-------
tABLE 34. PERFORMANCE OF RETENTION/DETENTION CONTROLS,
ORANGE COUNTY, FLORIDA3
Stormwater
control measure
Swale/
percolation
Underdrain
Residential
swale
Detention/
sedimentation
Storms
sampled
4
4
2
6
Influent load, Kg/yr
BOD5
101
118
34
193
N P
32.84 9.69
24.69 6.53
6.96 1.89
59.11 21,76
SS
2,764
5,206
1,504
8.112
Effluent
BOD5
7.42
5.31
21.17
77.66
N
4.28
11.02
5.83
14.23
load, Kg/yr
P
0.78
0.49
2.00
5.24
SS
108
63
164
1,332
Ave.
BOD5
93
96
38
60
'removal , %
N
90
54
16
76
V
92
93
0
76
SS
96
99
89
84
a. Source: references 7-52, 7-53.
-------
The cover of grass, weeds and organic debris was found to be extremely
effective in intercepting and adsorbing most of the 2,4-D discharged
from the cropped area. This occurred in spite of the fact that (a) high
rates of artificial rainfall were used, and (b) 2,4-D is reportedly very
mobile in soils in comparison to other pesticides. The study suggests
that more strongly sorbed compounds would be even more effectively
removed by grassed waterways. Overall, diversion of agricultural runoff
from cropped areas through grassed waterways or adjoining vegetated
areas can provide for substantial reduction of agricultural chemical
discharges to streams.
A problem associated with storm runoff and flood water can be the
entrainment of high levels of sediment. In a study conducted at the
Institute of Water Utilization (now the Water Resources Research
Center), at the University of Arizona, two experimental sites near
Safford, Arizona, were evaluated to determine the effectiveness of grass
filters for sediment reduction in flood water destined for artificial
recharge facilities [7-67],
One .site at Safford Agricultural Experiment Station was studied for a
period of three years from 1961 to 1963. Seven experimental border
checks were established on a 1.84 ha site of the field station, having
an average slope of 0.10 percent. Six of the plots were seeded or
planted with two types of bermudagrass and other grasses. The seventh
plot was seeded with Lahontan alfalfa. The second experimental site
was studied in 1963. Two border checks were established on a 1.2 ha
site, which had an average slope of 0.60 percent. Coastal and common
bermudagrass were planted on the two plots. Grass filtration was found
to be extremely effective in removing up to 99 percent of the sediment
entrained in the test water with the two varieties of Bermudagrass
tested at the Safford test site.
The study found that grass filters promote mechanical sedimentation by
retarding the flow velocity and consequently, enhancing particle
settling. A second possible mechanism for sediment removal, which
constitutes a much smaller effect,,is the adsorption of the
col lodi al -size particles to grass surfaces. On the basis of the
experimental results at Safford, it appears that grass filtration is an
effective, economical, first-stage procedure for reducing sediment in
flood water.
175
-------
REFERENCES
7- 1. Tourbier, J. ahd.R.W. Pierson, Ur'i (eds;). Biological Control of
Water Pollution; University of Pennsylvania Press, Philadelphia,
Pa., 1976.
7- 2. Tilton, D.L., R.H. Kadlec and C.J. Richardson (eds). Freshwater
Wetlands and Sewage Effluent Disposal, Symposium Proceedings.
University of Michigan, Ann Arbor, Mi., 1976.
7- 3. Seidel , K. Macrophytes and Water Purification. In: Biological
Control of Water Pollution, J. Tourbier and R.W. Pierson, Jr.
(eds). University of Pennsylvania Press. Philadelphia, Pa.,
1976.
7- 4. Kadlec, R.H. and D.L. Tilton. Waste Water Treatment Via Wetland
Irrigation: Nutrient Dynamics. J_n: Environmental Quality
through Wetlands Utilization - Proceedings from a Symposium
Sponsored.by the Coordinating Council on the Restoration of the
Kissimmee River Valley and Taylor Creek-Nubbin Slough Basin,
Tallahassee, Fla., February 28-March 2, 1978.
7- 5. Tilton, D.L. and R.H. Kadlec. The Utilization of a Freshwater
Wetland for Nutrient Removal from Secondarily Treated Wastewater
Effluent. Jour. Environ. .Qual. 8(3):328, 1979.
7- 6. Kadlec, R.H. and D.L. Tilton. Monitoring Report on the Bellaire
Wastewater Treatment Facility. University of Michigan Wetlands
Ecosystem Group, University of Michigan, Ann Arbor, Mi., 1978.
7- 7. Spangler, F.K., W.E. Sloey and C.W. Fetter. Artificial and
Natural Marshes-as Wastewater Treatment Systems in Wisconsin.
In: Freshwater, Wetlands and Sewage .Effluent Disposal, D.L.
Ti?ton, R.H. Kadlec and C.J. Richardson (eds). University of
Michigan, Ann Arbor, Mi.,1976.
7- 8. Whigham, D.F. and R.L. Simpson. The Potential Use of Freshwater
Tidal Marshes in the.Management of Water Quality in the Delaware
River. ln_: Biological Control of Water Pollution, J. Tourbier
and R.Wi . Pierson, Jr. (eds). University of Pennsylvania Press,
Philadelphia, Pa., 1976.
7- 9. Valiela, I.,. J.M. Teal and W. Sass. Nutrient Retention in Salt
Ma-rsh Plots Experimentally Fertilized with Sewage Sludge.
Estuar. Coastal Mar. Sci. 1:261, 1973.
7-10. Fetter, C.W., W.E. Sloey and F.L. Spangler. Use of a Natural
Marsh for Waste Water Polishing. Jour. Water Poll. Control Fed.
50(2):290, 1978.
176
-------
7-11. Spangler, F.L., W.E. Sloey and C.W. Fetter. Wastewater Treatment
by Natural and Artificial Marshes. EPA-600/2-76-207, 1976.
7-12. Spangler, F.L, W.E. Sloey and C.W. Fetter. Experimental Use of
Emergent Vegetation for the Biological Treatment of Municipal
Wastewater in Wisconsin. In: Biological Control of Water
Pollution, J. Tourbier and R.W. Pierson, Jr. (eds). University of
Pennsylvania Press, Philadelphia, Pa., 1976.
7-13. Fritz, W.R. and S.C. Helle. Cypress Wetlands for Tertiary
Treatment. Boyle Engineering and Corporation, Orlando, Fla.,
March 1979.
7-14. Fritz, W.R. and J.C. Helle. Cypress Wetlands: A Natural Tertiary
Treatment Alternative. Water and Sewage Works, 126:4, 1979.
7-15. Mitsch, W.J., H. T. Odum and K.C. Eivel. Ecological Engineering
through the Disposal of Wa.stewater into Cypress Wetlands in
Florida. National Conference on Environmental Engineering
Research, Development and Design. University of Washington,
Seattle, Wa., 1976.
7-16. Boyt, F.L., S.E. Bayley and J. Zoltek, Jr. Removal of Nutrients
from Treated Municipal Wastewater by Wetland Vegetation. Jour.
Water Poll. Control Fed. 49(5):789, 1977.
7-17. Zoltek, J., Jr., S.E. Bayley et al. Removal of Nutrient from
Treated Municipal Wastewater by Freshwater Marshes, Progress
Report to City of Clermont, Florida. September, 1978.
7-18. Small, M.M. Marsh/Pond Sewage Treatment Plants. In: Freshwater
Wetlands and Sewage Effluent Disposal, D.L. Tilton, R.H. Kadlec
and C.J. Richardson (eds). University of Michigan, Ann Arbor,
Mi., 1976.
7-19. Demgen, F.C. Wetlands Creation for Habitat and Treatment - At
Mt. View Sanitary District, California, Paper presented at the
Aquaculture Systems for Wastewater Treatment Seminar, University
of California, Davis, Ca., September, 1979.
7-20. Williams, T.C. and J.C. Sutherland. Engineering, Energy, and
Effectiveness Features of Michigan Wetland Tertiary Wastewater
Treatment Systems, Paper presented at the Aquaculture Systems for
Wastewater Treatment Seminar, University of California, Davis,
Ca., September, 1979.
7-21. Hartland-Rowe, R.C.B. and P.B. Wright. Swamplands for Sewage
Effluents: Final Report. Environmental-Social Committee
Northern Pipelines, Report No. 74-4. Information Canada Cat. No.
R72-13174, #QS-1553-000-E-A1, Canada, May, 1974.
177
-------
7-22. Mudroch, A., and J.A. Capobianco. Effects of Treated Effluent on
a Natural Marsh. Jour. Water Poll. Control Fed. 51(9):2243,
1979.
7-23. Yonika, D. and D. Lowry. Feasibility Study of Wetland Disposal
of Wastewater Treatment Plant Ef f 1 ue.nt,. Fi na 1 Report.
Commonwealth of Massachusetts Water Resources .Commission,
Research Project 78-104, 1979.
7-24. Steward, K.K. and W.H. Ornes. Assessing Marsh Environment for
Wastewater Renovation. Jour. Water Poll. Control Fed. 47(7):
1880, 1975.
7-25. Shih, S.F., A.C. Federico, J.F. Milleson and M. Rosen. Sampling
Programs for Evaluating Upland Marsh to Improve Water Quality.
Amer. Soc. Agric. Eng. 0001-2351/79/2204-0828502.00, 1979.
7-26. Grant, R.R., Jr. and R. Patrick. Tinicum Marsh as a Water
Purifier. Hearings of Committee on Merchant Marine Fisheries,
November 5, 1971, (92-71) pg. 173-191, 1971.
7-27. DeJong J. The Purification of Wastewater with the Aid of Rush or
Reed Ponds. In: Biological Control of Water Pollution, J.
Tourbier and O/. Pierson, Jr; (eds). University of Pennsylvania
Press, Philadelphia, Pa., 1976.
7-28. Small, M.M. Meadow/Marsh Systems as Sewage Treatment Plants.
Brookhaven National Laboratory, Upton, N.Y., 1975.
7-29. Small, M.M. Brookhaven's Two Sewage Treatment Systems. Compost
Science 16(5):7, 1975.
7-30. Small, M.M. and C. Wurm. Data Report, Meadow/Marsh/Pond System.
Brookhaven National Laboratory, Upton, N.Y., 1977.
7-31. Small, M.M. Data Report, Marsh/Pond System. Brookhaven National
Laboratory, Upton, N.Y., 1976.
7-32. Demgen, F.C. and J. W. Nute. Wetlands Creation Using. Secondary
Treated Wastewater. Proceedings Water Reuse Symposium, Vol. 1,
Washington D.C., March, 1979.
7-33. Cederquist, N. Waste Water Reclamation and Reuse Pilot
Demonstration Program for the Suisun Marsh - Progress Report,
March 1977. U.S. Bureau of Reclamation, Sacramento, Ca., 1977.
7-34. Nute, J. W. Marsh/Forest Demonstration Project - Feasibility
Assessment. J. Warren Nute, Inc., San Rafael, Ca., 1979.
178
-------
7-35. City of Arcata. Proposal for a Marsh Wastewater Treatment and
Reclamation Project. Clean Water Grant Project Proposal, June
1979.
7-36. Sutherland, J.C. and F.B. Bevis. Reuse of Municipal Wastewater
by Volunteer Freshwater Wetlands. Proceedings, Water Reuse
Symposium, Vol. 1, Washington D.C., March, 1979.
7-37. Williams, T.C. Wetlands Irrigation Aids Man and Nature. Water
and Wastes Eng., 16:11, 1980.
7-38. Reed, S.C. and R.K. Bastian. Aquaculture Systems For Wastewater
Treatment: An Engineering Assessment. EPA 430/9-80-007, 1980.
7-39. Markanan, R.K., J.E. Balon; and A.C. Robinson. Review of Current
Interest and Research i.n.Water Hyacinth-Based Wastewater
Treatment. Final Report to National Aeronautics and Space
Administration, February, J.977.
7-40. Dinges, W.R. Development of Hyacinth Wastewater Treatment System
in Texas. Paper presented at the Aquaculture Systems for
Wastewater Treatment Seminar, University of California, Davis,
Ca., September, 1979.
7-41. Dinges, W.R. A Proposed Integrated Biological Wastewater
Treatment System. In: Biological Control of Water Pollution, J.
Tourbier and R.W. Pierson, Jr. (eds). University of Pennsylvania
Press, Philadelphia, Pa., 1976
7-42. Dinges, W.R. Upgrading Stabilization Pond Effluent by Water
Hyacinth Culture. Jour. Water Poll. Control Fed. 50(5), 1978.
7-43. Dinges, W.R. Who Says Sewage Treatment Plants Have to Be Ugly?
Water and Wastes Eng. 13:20, 1976.
7-44. Wolverton, B.C., R.M. Barlow and .R.C. McDonald. Application of
Vascular Aquatic Plants for Pollution Removal, Energy, and Food
Production in a Biological System. In: Biological Control of
Water .Pol 1 ution , J. Tourbier.and H7W. Pierson, Jr. (eds).
University of Pennsylvania Press, Philadelphia, Pa., 1976..
7-45. Wolverton, B.C. Engineering Design Data for Small Vascular
Aquatic Plant Wastewater Treatment Systems. Paper presented at
the Aquaculture Systems for Wastewater Treatment Seminar,
University of California, Davis, .Ca., September, 1979.
7-46. Wolverton, B.C. and R.C. McDonald. Upgrading Facultative
Wastewater Lagoons with Vascular Aquatic Plants. Jour. Water
Poll. Control Fed. 51(2):305, 1979.
179
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7-47. Sanks, R.L. and T. Asano. Land Treatment and Disposal of
Municipal and Industrial Wastewater. Ann Arbor Science
Publishers, Inc., Ann Arbor, Mi., 1976.
7-48. U.S. Environmental Protection Agency. Process Design Manual for
Land Treatment of Municipal Wastewater. EPA 625/1-77-008,
October, 1977.
7-49. Hickok, E.E., M.C. Hannaman and N.C.- Wenck. Urban Runoff
Treatment Methods: Volume I - Non-Structura'l Wetland Treatment.
EPA-600/2-77-217, Cincinnati, Ohio, 1977.
7-50. Association of Bay Area Governments. Treatment of Stormwater
Runoff by a Marsh/Flood Basin. Interim Report to EPA, August,
1979. :
7-51. Morris* F.A.-, M. K. Morris, T.S. Michaud and L.R. Williams,
Meadowlarid Natural Treatment Processes in the Lake Tahoe Basin:
A Field Investigation. U.S. EPA, Environmental Monitoring
Systems Laboratory, Las Vegas, Nev., 1980.-
7-52. East Central Florida Regional Planning Council .... Or! ando
Metropolitan Areawide Water Quality Management Plan 208, Vol. 3.
June, 1978.
7-53. Lynard, W.6., E.J. Finnemore, J.A. Loop and R.M. Finn. Urban
Stormwater Management and Technology: Case Histories.
EPA-600/8-80-035, August, 1980.
7-54. McCueri, R.H. On-site Control' of Naripoin't" Source Pollution. In.:
Proceedings: Stormwater Management Model (SWMM) Users Group
Meeting, November 13-14, 1978. EPA 600/-79-003, November 1978.
7-55. Residential Storm Water Management. PubKshetf jointly by the
Urban Land Institute, the American 'Society of Civil Engineers,
and the National Association of Home Builders, 1975.
7-56. Poertner, H.G. Practices in Detention of Urban Storm Water
Runoff. APWA Special 'Report-No. 43,- 1974v - \. ,
7-57. Rubin, H..., J.P. Glass and'; A. ' Huntv Analysis of Stormwater
Seepage Basins in Peninsular Florida. Water Resources Research
Center, Publication No. 39, University of Florida1, Gainesville,
Fla.,' September, 1976.
7-58. WernieliSta, M.P. Stormwater Management Quantity and Quality.
Ann Arbor Science Publishers, Inc.,' Ann Arbor, Mi'., 1978.
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7-59. Mynear, O.K. and C.T. Huan. Optimal Systems of Storm Water
Detention Basins in Urban Areas. U.S. Dept. Interior Project No.
B-046-KY, Water Resources Research Institute, University of
Kentucky, Lexington, Ky., 1977.
7-60. SaTt Lake County Division of Water Quality and Uater Pollution
Control. Salt Lake County Urban Runoff Program. November, 1979.
7-61. Biggers, D.J., J.P. Hartigan, Jr. and H.A. Bonuccelli. Urban
Best Management Practices: Transition from Single-Purpose to
Multi-Purpose Stormwater Management. International Symposium on
Urban Storm Runoff, University of Kentucky, Lexington, Ky, July,
1980.
7-62. Hantzsche, N. and J. Franzini. Utilization of Infiltration
Basins for Urban Stormwater Management. International Symposium
on Urban Storm Runoff, University of Kentucky, Lexington, Ky.,
July 1980.
7-63. Field, R. Urban Stormwater Management and'Pollution Abatement in
the United States, Workshop Notes on Storm Sewer Systems Design.
University of Illinois, Urbana, 111., 1978.
7-64. U.S. Department of Agriculture, Soil Conservation Service.
Handbook of Channel Design for Soil and Water Conservation.
SCS-TP-61, Washington, D.C. 1947, revised June, 1954.
7-65. Kouwen, N., R.M. Li and D.D. Simons. A Stability Criterion for
Vegetated Waterways. International Symposium on Urban Storm
Runoff, University of Kentucky, Lexington, Ky., July, 1980.
7-66. Asmussen, L.E., A.W.. White, Jr., E.W. Mauser and J.M. Sheridan.
Reduction of 2,4-D Load in Surface Runoff down a Grassed
Waterway. Jour. Environ. Qual. 6(2.): 159, 1977.
7-67. Wilson, L.G. Sediment Removal from Flood Water by Grass
Filtration. Trans. ASAE, pg. 35-37, 1967.
181
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SECTION 8
GUIDELINES FOR WETLAND SELECTION AND DESIGN
INTRODUCTION
This section presents basic guidelines for use in designing or selecting
wetlands for water pollution control. The review of case studies and
.removal mechanisms makes it all too clear that a universally applicable
theory of design for wetland treatment systems is not yet available.
Although there appear to be trends and repeatable results in pollutant
removal and wetland response, enough exceptions occur to indicate that
not all relevant factors are well understood. Major differences in
geographic location, climate, hydrologic regime, and type of wetland
appear to significantly affect wetland response to pollutants. Thus,
although there are 19 case studies reviewed in Section 7, only a few
pertain to any single physical/ecological situation.
This section presents general principles that appear to reflect
performance or conditions reported for most wetland systems. For more
detailed guidance, based upon past experiences with a specific type of
wetland in a specific climate, the original case studies reviewed in
Section 7 should be consulted.
SELECTION OF WETLAND
In the development of a wetland treatment system, two major choices must
be made. The first, is selecting a natural versus a constructed wetland.
.Some researchers recommend that constructed wetlands be used in
preference to natural wet! and* [8-1, 8-2, 8-3, 8-4].. This
recommendation appears to reflect a desire to protect natural wetlands
until the mechanisms of pollutant removal and assimilation are better
understood. Natural and constructed wetlands have advantages and
disadvantages, the importance of which will depend upon individual
circumstances.
Some advantages of natural wetlands include:
o immediate availability - no extended construction or
vegetation establishment period should be necessary;
o no new land requirements.
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Disadvantages of natural wetlands could include:
o inconvenient location;
o connection to critically sensitive water bodies;
o inadequate size to assimilate waste load;
o it may be required by regulatory authorities that discharges
to natural wetlands meet stringent, "polished" influent
criteria;
o operation of a managed wetland may alter ecosystem balance and
relationships.
To a large extent, the advantages of a constructed wetland complement
the disadvantages of a natural wetland. These advantages include:
o flexibility in site location;
o optimum size for projected waste load;
o construction of topographic features such as channels, shallow
bars, islands and levees to improve pollutant removals and
facilitate maintenance;
o possible exemption from rigorous influent criteria if wetland
is considered part of a treatment system;
o would supplement existing wetlands;
o ecosystem construction of a managed wetland could not be
judged an alteration of a natural wetland ecosystem.
Concomitantly, there are disadvantages to a constructed wetland,
including:
o cost and availability of suitable land;
o construction costs for grading and planting the site;
o unavailability of the system during the construction period;
o possibly reduced performance during vegetation-establishment
period.
If a constructed wetland is selected, a second choice, the type of
wetland that will be used, has to be made. Assuming that the necessary
geologic and. hydrologic conditions can be found, ponded or grassed
wetlands can be constructed almost anywhere. However, certain types', of
wetlands would probably not become successfully established outside of
their current geographical distribution. Cypress swamps will not
flourish in Wisconsin and peat bogs are not feasible for Arizona. In
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addition, wetlands planted with particular plant species, unless
rigorously managed, will become dominated by plant species tolerant of
'local hydro lo'gic and climatic conditions.
Nonetheless, sufficient choices among marshes, open ponds and forested
land remain and are discussed in more detail later in this section.
DESIGN FACTORS
'The factors affecting wetland performance and basic principles of design
can be used to plan a constructed wetland. These same factors and
principles can be used to assess an existing wetland for its suitability
as part of a treatment system. It must again be emphasized that local
conditions greatly affect the usefulness of wetlands for water pollution
.control and a site-specific evaluation must be conducted.
factors that have been identified in.the case studies include:
o type of wetland;
o hydrologic system;
o vegetative system;
o seasonal factors;
o nature of polluted water;
o loading rate;
o target pollutants. .
These design factors and principles or guidelines* based upon the case
studies'and removal mechanisms, are discussed below.
.Type of Wetland
The following seven basic .types of-wetlands have been identified:
o northern peatlands;
o cattail/grass marshes;
o southeastern swamplands;
o cypress domes;
o freshwater/tidal marshes;
o open ponds;
o meadows and seepage wetlands.
''All seven can be used for the treatment of polluted water. 'However, of
these seven, only four are Currently considered for constructed
wetlands:
o cattail/grass marshes;
o freshwater/tidal marshes;
o ponds;
o meadows and seepage wetlands.
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No guidance is available on the selection of one wetland over another.
Local conditions and needs may be prime factors in the selection of a
wetland system. Studies at the Brookhaven National Laboratory indicated
that a meadow-marsh-pond system performed slightly better than a
marsh-pond system [8-5, 8-6]. To the extent that different pollutants
are removed by different plants and mechanisms, a wetland system that
employs combinations of the wetland types should have improved overall
performance.
Hydro logic System
o Polluted Water Inflow
Flow of water to a wetland has three characteristics: quantity,
duration and frequency. Quantity, or loading, is discussed in the
following section. Duration and frequency are the principal
characteristics that distinguish municipal treatment plant effluents
from stormwater. Even allowing for daily and monthly flow variations,
treatment plant effluents are relatively steady. Stormwater influent to
a marsh will vary in duration and intensity among storms and seasons.
Wetlands that are permanently flooded, such a.s .cypress domes and
marsh-pond systems, can readily accommodate either .conti nuo us o.r
intermittant polluted water inflow. Such wetlands usually are connected
to other sources of water, such as a river, lake or ground water, and
their ecosystems are not dependent:upon the polluted water flow.
Wetlands that are not permanently flooded, such as some constructed
wetlands and meadow-marsh systems, may be sensitive to hyd.rologic
changes caused by the inflow of polluted water. Constructed wetlands
which rely upon continuous inflow may suffer during the dry periods
between stormwater inflows. On the other hand, the ecological balance
of intermittently-flooded wetlands may be disturbed when the water
supply becomes continuous. In either case, the wetlands will evolve
into different systems over time in response to changes in the
hydrologic regime. . .
The selection or design of the wetland should match the expected flow of
water. This is important for two reasons:
(1) Flooding of the wetland should coincide with the growth
requirements of the vegetation characteristic of that
wetland;
(2) Addition of pollutants to the wetland should coincide
with the vegetative growth phase during which those
pollutants are absorbed or metabolized by the plants.
For example, removal of phosphorus was found, in a number
of studies, to be a seasonal .phenomenon, with actual
Plant release of phosphorus in winter and early spring
8-1,8^7,8-8,8-9,8-10,8-11]. . . .
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o Inflow/Outflow Regulation
Because of the temporal variations in stormwater runoff quality, the
idea of selectively regulating the inflow to wetland treatment areas is
a promising one where conditions so permit [8-28]. Work has been done
in Florida to utilize infiltration areas and retention basins for
containment and treatment of the "first flush" component of runoff
[8-12, 8-13, 8-14], In one instance, automatic gates were installed to
control inflow to the off-channel treatment pond in accordance with
streamflow conditions. This approach may apply equally well to
artificial wetlands and some natural wetlands amenable to flow
regulation.
It may be desirable to regulate the outflow from wetlands for flood
control and water quality control. The use of dikes, weirs and other
overflow structures can be employed selectively to increase wetland
storage and detention time. For instance, sb-me have suggested the
retention of runoff flows during springtime flashing [8-15,]. The
objective would be to store runoff'waters until marsti'communities were
'functioning at high uptake rates. This management approach would have
to account for hydraulic surges in runoff, and possibly provide for
diversion of a portion of the flow around the wetland*
o Seasonal Application
Whereas very little can be done to influence the timing of stormwater
discharges to wetlands, small wastewater flows may be retained in
holding basins for seasonal application to take greatest advantage of
biological treatment processes. The timing of discharges should take
Hnto account (a) biological activity within the wetlands, (b)
availability of dilution flows (i.e., rainfall and runoff), and (c)
seasonal uses and quality of waters downstream of the wetland discharge.
Exempt from this approach are wastewater discharges to palustrine inflow
and seepage wetlands, for which seasonal aspects generally need not be
considered, providing soil conditions are suitable for phosphorus
adsorption or nitrate reduction [8-15].
Seasonal flushing of wetlands is an important management consideration.
Spring flushing of nutrients and organic matter can be especially
.detrimental to receiving waters in contributing to summer algal problems
[8-16, 8-17]. . IJT-coastal areas, increased discharge of nutrients from
Wetlands may further aggravate red tide problems, which have been linked
in some instances to the flushing of freshwater marshes [8-18].
The suggestion has also been made to use flushing flows to strip
nutrients from the wetland system after they become mobilized in late
autumn [8-15]. Whether or not further treatment may be required for
such concentrated discharges would depend on the nature of receiving
water impacts at the time of flushing. For artificial and small wetland
systems, it may be feasible to divert concentrated flushing flows for
'.final treatment by upland soils and vegetation [8-15].
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o Flow Routing
The manner in which wastewater flows are introduced and distributed
within wetlands is an important management consideration. Several
investigators have recommended that urban and agricultural runoff waters
be directed into marsh areas rather than open water bodies within
wetlands [8-19, 8-20]. The objective here is to maximize the effective
contact between wastewaters and wetland soils and vegetation, and avoid
short-circuiting of pollutants through the system. Even greater
interaction with soils and vegetation can be achieved by applying the
waste flow on upland areas adjacent to wetlands [8-18], Higher rates of
nutrient removal may be attained by virtue of the greater amount of
seepage and soil contact which this technique provides [8-20]. Careful
consideration must be given to the scouring effects of stormwater flows
in high marsh and upland areas. In addition to healthy vegetative
cover, rock berms and other types of energy dissipation structures may
be needed to protect these highly erodible soils.
Fbllutant removal effectiveness within the wetland depends upon wide
distribution and circuitous flow, paths. In natural wetlands, there may
be little that can be done to enhance this .aspect of pollution, control
without altering the ecosystem. Where canal.s may be constructed in
wetlands for purposes of navigation, mosquito control or other
development activities, certain practices have been recommended to
minimize disturbance of pollutant removal and other inherent wetland
functions. These include:
(1) Limit construction of canals that connect the edge of the
hydrological basin to the middle (shortens flow-through
and detention time) [8-21];
(2) Limit construction of blind-end canals or finger-fill
developments (leads to poor circulation and bypassing of
flows) [8-22];
(3) Limit construction of impoundments in marsh areas
(decreases marsh/treatment areas) [8-23];
(4) Allow periodic openings in dredge spoil banks so water
circulation is not impeded [8-23, 8-24]. .
In the creation or reconstruction of wetlands, more leeway is possible
in directing water flow through the system. The researchers at the
Brookhaven National Laboratory strongly suggest that water be routed
through a mix of wetland features (i.e., meadows, marshes, islands and
open water) [8r6], This structural diversity provides more biological
niches and greater opportunity for assimilation of pollutants in passage
through the wetland. A hypothetical comparison of overall removal
efficiency of an unbroken versus a compartmentalized wetland, as
proposed by Blumer [8-35], is provided in Figure 9. Examples of
alternative wetland arrangements that might be selected to enhance the
removal of nutrients and other pollutants are shown in Figure 10.
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Removal Efficiency
90%
influent
10 mg/l
10 mg/l
influent
I0mg/l
Unbroken Wetland
Removal Efficiencies per Compartment
30% 60% 85%
10 mg/l
7.0 mg/l
Z.8mg/l
Compartmentalized Wetland
effluent
1.0 mg/l
Figure 9. Comparison of renovation potential of two
hypothetical wetland systems.
a. Source: reference 8-25.
effluent
0.42 mg/l
188
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Wetland with straight-through
flow least desirable.
Island wetland meadows with
increased trapping surface and
shape intercepts flow and
sediments. ...
5f sediment traps
Wetlands placed in meandering
sequence. Flow forced to migrate
around edges.
w₯ / '*
jl crayfish or other
harvestable crop
Wetland drainage channels with
intermittent and terminal ponds.
Figure 10... Alternative wetland arrangements designed for
increased nutrient retention which might be
possible in constructed wetland areas.
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o Water Level Maintenance
Water levels within wetlands are closely related to pollutant removal
functions and flow distribution. Manipulation of water levels through
the use of weirs, dikes, flow regulation, etc., must take into account
the competing needs and resultant effects in different portions of the
wetland. For example, best pollutant removal efficiencies are
reportedly achieved with shallow water depths [8-26], To induce shallow
flow in meadows and high marshes may require impoundment and greater
depth of flow in lower ponds and channelized sections of the wetland.
This alteration in flow regime is likely to increase sedimentation
rates, but may bring about undesirable changes in soil and vegetative
uptake of pollutants in the affected open-water areas. Clearly,
tradeoffs must be made to obtain the optimum pollutant control
effectiveness through water level manipulation in wetlands. This must
.proceed from a very thorough understanding of the interrelationships of
flow regime and ecosystem functions throughout the entire wetland.
o Infiltration '
Wetlands management for pollutant removal should focus on providing the
greatest amount of soil-water contact. Seepage of ground-water influent
systems are most desirable because of the opportunity for wastewater
purification within the soil mantle. The cypress wetlands of Florida
provide ample evidence [8-27, 8-28], Hydraulic routing of wastewaters
.and runoff should take maximum advantage of permeable soil areas within
wetlands to provide infiltration. Also, sandy soils may be imported to
form filtering devices in channelized sections [8-25].
Construction of artificial seepage wetlands has met with success in some
instances. The.objective is to create conditions where vertical and
lateral water movement is slow enough to maintain high soil moisture and
allow wastewater renovation, yet rapid enough to prevent surface
overflow [8-29]. Sutherland has found the mast useful types of soils to
be silty in composition with hydraulic conductivities in the range of
10"^ to 1
-------
plant species, if any, presumably emerge because of their ability to use
the new nutrient source (wastewater), or because of their tolerance to
the pollutants. Such a system response should therefore be beneficial
to the objective of pollutant removal.
In the construction of wetlands, the selection of vegetation should be
guided by climate, hydrology and the response of plants to pollutants.
The plants discussed in Section 5, such .as Elodea, duckweed, water
hyacinth, cattail and sedge, each have a particular environmental
requirement for growth. It should be safe to assume that use of these
plants, in their native geographical areas, will result in their
retention in the wetland. Use of these plants in areas where they are
not native, may result in their ultimate replacement by local plant
species.
The findings presented in Section 7 indicated that diversity of
vegetation, and of hydrologic regimes, improved a .wetland's overall
pollutant removal. Monocultures of water hyacinth have been used
successfully in intensively managed aquaculture systems.. -However, for
wetlands with diverse ecological niches, and which are intended for
multiple uses, a diversity of vegetation approximating a natural system
is recommended.
Section 5 presented three basic plant groups: (a) floating, (b)
emergent, and (c) submerged. Each .group contains species .which
demonstrate high uptakes of specific pollutants. .The selected plant mix
should match the plant species with the pollutants of concern.
Vegetation also serves as a filtration system, and a support medium for
microorganisms which metabolize organic substances, and nitrify
ammonium. To optimize the microbiological removal mechanisms,
vegetation that forms dense stands of submerged stems and leaves, or has
heavy, thick floating root mats should be selected.
o Establishment of Vegetation
Whereas landforming for the creation of channel's, ponds and islands
represents a simple, application of common dredging and grading
techniques, establishing vegetation in a .constructed wetland is an
unfamiliar procedure to most engineers.
New vegetation may be established in a. constructed wetland from seed or
transplants, or by natural establishment* Commercial nurseries
generally do not carry seeds or plant materials common to wetlands. The
best source is a wetland similar, to .the constructed system. When a
constructed wetland, is near a natural wetland; there will be movement of
seeds and plants to the constructed system. The East Bay Regional Park
District in California uses transplanted material to the extent
permitted by funds [8-31]. In the establishment of new or reconstructed
marshes, cattails have been planted over 5 to 50 percent of the suitable
land area. The vegetation has then become fully established within
three to five years.
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Seasonal Factors.-..
The seasons are ah important infl uence on all wetlands. This is a
natural consequence of reduced biological activity.'
Most case studies reviewed in Section 7 identified seasonal variations
in pollutant removal. In northern climates with freezing winter
temperatures, removals of BOD and phosphorus substantially decreased
during the cold season and in warm-climate wetlands", annual dormancy of
some vegetation produced similar decreases. In contrast, summertime
algal production increased effluent BOD and suspended solids at the
Martinez, California marsh [8-32, 8-33],
The following guidelines for dealing with seasonal effects on wetlands
are proposed:
(1) Physical pollutant removal processes, such as
sedimentation or adsorption on sof.l: b.r .peat, are. less
likely to be affected by the season. Wetlands' relying on
these processes can be designed for year-round operation.
(2) Biological removal processes, such as for nutrients or
BOD, can be substantially affected by the season ,
particularly in cold-weather climates. Low winter
temperatures may kill some plant species and will lower
the metabolic rate, and hence the pollutant assimilation
rate, of bacteria. When poor removal or poor
assimilation of pollutants is unacceptable, alternative
discharge locations or seasonal storage of the polluted
water must be provided.
(3) Deep water systems such as ponds or swamps are less
likely to be affected'by cold weather rthari shallow ponds
or meadows, where influent'can build up in frozen layers
over the winter, and be di scharged alncst untreated in
the spring.
(4)" Where sea'sonal plant dormancy can adversely affect a
constructed wetland's pollutant removal efficiency,
providing a diversity of vegetation will minimize the
deficiencies of any single species.
Nature of .Polluted Water,
Two basic groups of polluted water can be considered for treatment by
wetlands. Treated municipal wastewaters can be discharged to wetlands
as a po1ishing step, to further remove relatively low levels of
polluting constituents. Urban runoff, which, as discussed in Section 3,
contains substantial amounts of pollutants, can be discharged through
wetlands to protect a more sensitive or valuable receiving water.
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As discussed under Polluted Water Inflow, wastewaters differ from
stormwaters in their flow. As noted in Section 3, they also differ from
stormwaters in their constituent concentrations. The concentration of
treated wastewater poll utants applied to wetlands, as reported in the
case studies in Section 7, are presented in Table 36.
TABLE 36: APPLIED POLLUTANT CONCENTRATIONS
Treated wastewaters, range mg/1
Pollutant Marshes Hyacinth ponds Experimental
BOD5
Suspended solids
Total Kjeldahl nitrogen - N
Ammonium nitrogen - N
Total phosphorus - P
19-44
22-154
" - . '. '
4-23
.. 7-11
0.4-11
19
46
4
2
15
110-173
97-353
: 12-25
8
,4-7
The value of determining influent pollutant concentrations is to help
establish a'correlation with pollutant removals. The wetlands reported
in the case studies achieved removals of all pollutants, though not
always year-round. No correlation between concentrations and removal
performance was noted among the case studies, indicating other
overriding factors. Stowell et al., studied the removal of BOD,
suspended solids and phosphorus in relationship to influent
concentrations or loading in water hyacinth and marsh systems [8-35],
Their data indicate BODs removal in proportion to loading (Figures 11
and 12); however, the relationships between loading and suspended solids
and phosphorus were unclear. , . . -
A correlation between influent pollutant concentrations and wetland
damage or stress may be. hypothesized. System stress, with marked
reduction in species diversity, was noted at Hay River [8-34]. However,
a comparable concentration of pollutants were discharged at Great
Meadows [8-10 J with no apparent system stress, and even higher levels
were accommodated in the artificial Brookhaven National Laboratory
system [8-5, 8-6]. .
With no clear rationale for matching influent water quality to a
wetland, and with several years of research still to be conducted before
sufficient information is collected, caution should characterize the
application of polluted waters to wetlands. In general, the following
application guidelines are recommended:
193
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250
200
4 150
2'
4>
o
o
100
50
Primary effluent
o Secondary effluent
50 100 150
BOD5loading, kg/(ho)(d)
200
250
Figure H Effect of BOD loading on BOO removal in water hyacinth systems9
(data summarized from 16 studies).
a. Source: reference 8-35.
194
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100
80
60
o
-------
(1) Natural and constructed marshes - secondary level treated
municipal effluents and stormwaters;
(2) Water hyacinth ponds - secondary to primary level
effluents and stormwater;
(3) Intensely managed constructed syste'ms - primary level
treated municipal effluents must still be considered
experimental.
Loading Rate
The loading rate of a polluted water upon a wetland should correlate
with pollutant removal and'-system response. Two types of loading are
considered: (a) hydraulic loading, and (b) application of individual
pollutants. Wetlands peffbrfflance and response (health of the ecosystem)
are also determined by type of wetland, vegetation, hydfOlogic factors,
climate and Season. Thus, it is difficult to establish firm
relationships between loading and performance fro'm the few case studies.
The problem is compounded somewhat by differences -In measurement
techniques and.reporting of the parameters of concern.
Table 36 summarizes reported loading rates for the case studies in
Section 7. The selected loading rate for a planned discharge may be
compared to -those in"'Table 36j but should be evaluated for the specific
circumstances of the project.
Target Pollutants
One objective of any wetland treatmeht system will be the alleviation or
prevention of a water pollution problem. The problem will usually be
associated with One specific poUutant or a set of pollutants, such as
oxygen-demanding organic wastes, . n1tF§f§n» phosphorus or heavy metals.
The selection or design 9 f 3 Wetland should provide the removal
mechanisms, (physical of biological) effective for the pollutants of
concern, these mechanisms have not been completely documented and their
interrelationship is not ful ly .understood. However, certain
'relationship's can be inferred from thg 6a§§ Ittidies and from research on
.individual plant species*
Sections 4 and 5 presented in great detail 4H§ physical, chemical and
biological pollutant removal mechanisms in a wetland. TH@ processes are
complex and do not act independently. Vegetation enhances sedimentation
of suspended and colloidal pollutants; sedimentation makes available
many pollutants for use by vegetation; arid certain plant species are
substantially more effective than Others in removing specific metals or
nutrients*
It should be noted that the relationships presented Below are Subject to
confirmation by further studies of wetland systems. H5w'§ver, to the
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extent that one or several important pollutants are best removed by a
specific process, that process should be emphasized in the wetland, as
in the following examples::
(1) Meandering channels, with slow-moving water and large
surface areas, enhance settleable pollutant removal by
sedimentation.
(2) Seepage wetlands or shallow flow regimes are effective
for removal of pollutants such as phosphorus and metals
by adsorption to the soil.
(3) Seepage wetlands, meadows and thickly vegetated wetlands
are particularly useful for filtering colloidal
suspensions and where filtration is important.
(4) Rapid plant growth, generally associated with harvesting,
optimizes nutrient removal. For such applications, a
monoculture system, such as hyacinth ponds, can be very
.effective. Fbweyer, large amounts of vegetation must be
harvested. Stowell estimates 7kg of hyacinths may need
to be harvested.per m^ of wastewater treated [8-1].
(5) Nitrogen removal by denitri fication will occur in
anaerobic bottom sediments common to wetlands. Deep
areas, where sediments and organic detritus can
accumulate in ,an -anaerobic environment should be designed
into a wetland intended for nitrogen removal.
(6) BOD removals in wetlands'are accomplished by.
microorganisms. Optimum BOD removal will be achieved
where there is high surface area (soil, plant stems,
leaves and roots) for microbial growth, uniform
distribution of the BOD load, and adequate dissolved
oxygen. Open water surfaces in the wetland will increase
oxygen transfer to the water.
(7-)-- Because many .pl-ants are selective in.their accumulation
and biomagnification of various heavy metals, mixed
.-.stands of vegetation may provide the best overall heavy
metal removals, ;
(8) As demonstrated in the Brookhaven National laboratory
studies [8-5, 8-6], varied or mixed wetland systems
containing features of ponding for sedimentation, shallow
areas for adsorption by soil, and mixed vegetation, have
high potentials for treating typical primary level
municipal wastewaters with significant concentrations of
many pollutants. .
197
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Contingencies
Wetlands receiving either treated wastewater discharges or urban
stormwater may be subjected to transient high loadings of some
pollutants. This may be due to treatment plant failure, unusually high
soil erosion in the watershed, or a chemical spill in the watershed.
Contingency plans and special facilities should be prepared for natural
an.d constructed wetlands. The contingency may be simply an emergency
bypass, if the ultimate receiving water can accept the degraded
discharge. Where this is not possible, and the .wetland may be harmed by
overloading, storage of the influent might be appropriate.
For a new constructed wetland in the City of Fremont, California, ABAG
has included a protection measure as part of the preliminary marsh
design. A sediment trap will be included between the urban stormwater
conveyance channel and the marsh. This would intercept heavy loads of
sediment expected from new construction in the watershed. The discharge
from the sediment trap to the marsh will be by submerged conduits with
lift gates. In the event of an oil or gasoline spill in the watershed,
the trap should serve to capture the floating material.
It is beyond the scope of this report to develop contingency measures.
However, it is recommended that any wetland used for pollution control
be provided some measure of protection a.gainst accidental releases of
damaging substances., . ... .:
SECONDARY ENVIRONMENTAL IMPACTS
The primary impacts of polluted water discharge to wetlands have been
discussed and include:
o pollutant destruction; '
o pollutant accumulation in sediments and plants;
o possible changes in the balance of the plant community. '
Secondary impacts that may be associated with the use of wetlands for
pollution control include:
o disease vector organisms; .
o nuisance organisms; .
o odors; . : ..
o fog generation.
These secondary impacts are discussed below.
Disease Vector Organisms
Mosquitos are the di sease vector organisms associated with natural or
constructed wetlands. Marshes may produce several species of
mosquitoes. Some species cause nuisance problems, while others may
198
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transmit disease, constituting a public health hazard. Throughout the
U.S., various researchers and public health agencies have devoted
considerable effort to investigation of mosquito . control [8-36, 8-37,
8-38, 8-39, 8-40], The fol lowing marsh conditions have been found to
deter or limit access by natural predators and thus be conducive to the
uncontrolled production of mosquitoes:
o the presence of emergent, submergent and floating vegetation;
o flotage (debris) on the water surface;
o extensive shallow areas;
o irregular margins of the marsh;
o poor water quality;
o periodic water-level fluctuations.
The primary management tools that have been promoted for mosquito
control in marshes focus on natural predation (Gambusi a affinis ,
mosquito fish), channelization and water level manipulation [8-41,
8-42], Table 37 provides guidelines established by the ATameda County
(California) Mosquito Abatement District for marsti ,and mosquito
management [8-42], The guidelin.es are designed to enhance natural
predation by fish on mosquito populations, while at the same time
avoiding conflict with the objectives of marsh planners. ' .', "'"
Nuisance Organisms ^ V ^ ;;'
'Nuisance-organisms may be- hatural'-inhabfta'ri'ts of ''&' wetland "that 'are a
nuisance due to their proximity to urban areas. Such organisms include
various species of wildlife that could be considered desirable
indicators of a healthy, "natural" system. If necessary, this wildlife
can be trapped and relocated to other areas.
Some nuisance organisms can be detrimental .to the wetland treatment
system. Specifically, the burrowing of muskrats can weaken dikes and
levees. If these structures are essential features of the wetland, the
muskrats must be removed from the sensitive areas.
There is also a: risk that plant species introd,uced into wetland/systems
may become nuisances. Water hyacinth is a nuisance plant in many parts
of the southern United States,: where it clogs, waterways and water, supply
structure's. Where the gro'Wth o:f such a nuisance plant cannot be
tolerated, then the selected wetland treatment system should employ
other plant species native to the area.
Odors
Odprs from wetland treatment systems are associated with anaerobic
.decomposition on a.nd in the sediment* They can be controlled '.by
assuring an aerobic water layer over the sediment. Where a wetland is
heavily loaded with organic wastes., artificial aeration may be needed,
199
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TABLE 37. RECOMMENDATIONS TO PREVENT MOSQUITO PROBLEMS ASSOCIATED WITH FRESHWATER MARSHES3-
Harsh parameter Recommendation Rationale
Design of new marsh or
modification of existing
marsh -
Provide deep water areas (I
meter or deeper) . ' ;
Avoid extensive shallow areas
ro
o
o
Avoid Irregular margins;
Provide sufficient quality, and
quantity of water '
Establish water control structures
Establish proper drainage
Preside access for marsh management
equipment
For maintenance of fish during dry periods. The fish
populations will provide the primary natural predator
control for the mosquito populations.
Thick emergent vegetation will occur, in time, in shallow
marsh areas. The effectiveness of mosquito predation by
fish and other invertebrate predators could be severely
limited by the presence of vegetation. It can be
recommended that slopes of the margins and islands of a
marsh be designed to be steep enough to reduce the volume
of areas of the continuous emergent vegetation. Fish
predation would be more effective If emergent vegetation
areas were limited to relatively narrow margins and small
Islands. Marshes designed In this manner could have
large amounts of vegetation, but they would have maximum
Interface with deep water areas where fish predators would
abound.
Extreme irregularity of the vegetated margins along the edge
of the marsh and the Islands should be avoided. Narrow coves
created by Irregularity of the margins would create vegetative
areas with limited access for fish. Gentle curving margins
would be more compatible with natural mosquito control.
This Is necessary to:insure the long-term availability of an
adequate supply of fish to prey upon the mosquitoes. Poor.
water quality, may result In fish kills. Inadequate water ,
supply may also result in fish kills 1f the water quantity
Is not sufficient fo:maintain the fish through the dry period.
The ability to manage the water level should be maximized.
Mosquito populations can be managed through water level
management.- In the event of excessive mosquito production,
drawing down the water for a short period of time from the
vegetation area would enable mosquito predators to prey
upon the larvae In the deep water areas.
This insures that, In the event of a draw down, all areas
drain to the deep water pools leaving no shallow isolated
pools where predator fish cannot reach mosquito larvae.
Aquatic or terrain equipment may be necessary to accomplish
control of mosquitoes or vegetation, or to plant fish. Manage-
ment plans should be formulated in advance and access designed
for the kind of equipment required to properly manage the marsh.
(continued)
-------
TABLE 37. (continued)
Marsh parameter
Recommendation
Rationale
Marsh operation and long-
term management
Management of vegetation
Dredging of main channels and ponds
Management of fish populations
Periodic monitoring of mosquito
populations
Management of water levels.
Emergency Insecticide applications
Thinning or removal of vegetation allows for more open
water in vegetation stands and greater access for predator
fish. Nuisance plant species can also be selectively
removed.
Perform as necessary to remove silt deposition and maintain
deep water areas as desired.
Limit overcrowding of fish and depletion of fish food items.
Transfer fish to areas with low fish populations to ensure
adequate mosquito control.
Mosquito production should be monitored to determine If
Immediate control measures such as water drawdown, transfer
of fish populations or insecticide applications are necessary.
Water level may be drawn down to concentrate mosquitoes and
fish in deep water areas; or water levels may be raised to
allow fish to enter Into previously shallow inaccessible
areas for predatlon.
Insecticides should be applied as necessary to control excessive
mosquito larvae. (The frequency of Insecticide applications
will be a function of proper design and management of the
marsh. A properly designed marsh with effective management
should require no Insecticide applications).
a. Derived from reference 8-42.
-------
not only for odor control, but also to assure microbial degradation of
the waste. For lightly loaded wetlands, a passive aeration system would
consist of open^ stretches of water for oxygen exchange.
Fog Generation
Generation of fog can occur when the water temperature exceeds the air
temperatures and the moisture content of the air is near saturation.
Fog will be a .particular hazard at roads and highways. Little is known
about control of fog generation in wetland systems.
Beneficial Secondary Impacts
It is becoming increasingly clear that creation of artificial wetlands
holds substantial promise- as a means of attaining improved water quality
management in concert with other social and environmental objectives.
Interest and work in the field of wetlands development i.s. not new.
Promotion and guidance have come for many years-from fish and wildlife
preservationist organizations and. agencies. A thorough, text on the
subject was published in 1969 by the State of Wisconsin, Department of
Natural Resources [8-43], It covers practices related to such aspects
as impoundment construction, water level manipulation, wetland farming,
nesting island construction and vegetation control., the primary.
emphasis is on management of waterfowl habitats. Another useful
reference on the subject addresses artificial wetlands development in
conjunction with highway construction [8-2].
These references address many of the basic planning and design
considerations pertaining to artificial wetlands-pollution control
projects, insofar as maintenance of a functional wetland ecosystem is
concerned. Some of the key parameters and management guidelines are
listed in Table 38.,
The methodology for incorporating pollution control objectives into
wetland development projects is undefined at the.present time. As
pointed out .in this section, consideration may need-to be given to such
factors as:
o regional hydrology;
o ecosystem/hydrologic responses;
o .wetland requirements for waterfowl or.other environmental
objectives;
o hydrologic-pollutant removal relationships.
MAINTENANCE
Very little information is available about maintenance of wetland
systems used for pollution control. Maintenance of hyacinth pond
202
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TABLE 38 . WETLANDS DEVELOPMENT AND MANAGEMENT GUIDELINES
FOR WATERFOWL ENHANCEMENT3
Parameter
Criteria
Size
o Watershed to wetland ratios of 20:1 (rolling hills)
to 30:1 (feather terrain) are commonly recommended
by U.S. SCS. Local climatic factors and watershed
character may cause significant variation.
o Several small impoundments have greater positive
effect on waterfowl than one large marsh.
Sails
o Most desireable locations are poorly drained soils
with high water table or an underlying impermeable
layer.
o Additions of gravel or inorganic soil to existing
organic soils can improve stability for wetland
vegetation. .
Slope
Configuration
o <1 percent wetland slope recommended.
o Irregular shorelines offer substantially greater
support for, wildlife than small symmetrical im-
poundments.
Water depth o Not deeper than about 4 feet for fish sand wild! ife
needs.
.. .,.'..?,','-;. o Lower "quality soils (in. terras of productivity)
should be flooded at shallower depths, with poorest -
soil flooded <1 foot.
Composition o Mix of open water and emergent vegetation stands.
p 50-75 percent shallow enough _to achieve emergent plant
. growth (roughly 2 foot depth).
a. Derived from references (8-43) and (8-44).
203
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systems would be similar to that for waste stabilization ponds with the
following additional provisions:
o periodic harvesting and disposal of excess plant material;
o protection of hyacinths from cold weather; ;
o maintenance of structures to retain hyacinths in the pond.
Further information on hyacinth systems is available from Dinges [8-11]
and Middlebrooks [3-44].
Maintenance of marshes, seepage wetlands, swamps and bogs will be,
principally, repair of channels, berms and hydraulic control structures.
Harvesting of excess or dead vegetation obstructing waterways may be
necessary. Disposal of large volumes of plant material may pose a
problem. However, some plant material may be converted to animal feed,
compost or energy. The inclusion of resource recovery operations will
depend upon the economic viability of each project.
Stowell evaluated sediment accumulation in wetlands1* and concluded that
most bottom deposits will come from organic detritus of marsh vegetation
[B-35]. A sample calculation, based upon a wetland loading of 30
m3/(ha)(d) of wastewater containing 100-mg/l of suspended solids, shows
that the wetland would accumulate* at a capture efficiency of 100
percent, only 0.1 mm/y of bottom deposits due to influent solids. It
thus appears that sediment accumulation would not be a major problem
with most waters, ,and that channel dredging or cleaning may be an
infrequent operation.
COSTS
Few constructed wetlands 'have1 reported-construction, costs, and the basis
is not alwa'ys1 comparable. Costs are highly dependent upon .wetland type,
size, and location* Similarly, mavhtenance .costs are also project
specific. Tchobanoglous repo'rted-a comparison in capital and operating
costs between activated siudge wi th chlorination and primary
clarification, with constructed wetlands and chlorinatibn [8-45]. As
shown in Table 39, wetlands'costs are substantially lower.
TABLE 39: COMPARISON.OF WETLANDS AND ACTIVATED SLUDGE COSTSa
Activated sludge
Wetland
Cost element-;
June 1979
Capital cost, $ x
0 & M cost,($/y)x
10
10
6
3
0.1 ragd
' 0.71
35
0.5 mgd
1.23
78
1.0 mgd
1.6
117
0.1 mgd
0.37
21
0.5 mgd
0.55
48
1.0 mad
0.90
74
a. Source: reference 8-45.
204
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A wetlands receiving effluent from a secondary level wastewater
treatment system was recently constructed by the East Bay Regional Park
District in Hayward, California [8-31], Total grading cost in 1979 and
1980 was $550,000 for an 80-hectare wetland. Because the facility will
also serve as a regional recreational area, two bridges, gates, and a
parking area were added for $200,000. Finally, $100,000 was reserved
for transplanting vegetation to the marsh from other wetland areas.
205
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REFERENCES
8-1. Fetter, C.W., W.E. Sloey and F.L. Spangler. Use of a Natural
Marsh for Waste Water Polishing, Jour. Water Poll. Control Fed.
50(2):290; 1978. . .
8-2. Grant, R.R., Jr. and R. Patrick.' Tinicum Marsh as a Water
Purifier. Hearings of Committee on Merchant Marine Fisheries
November.5,. 1971, (92-71) pg. 173-191, 1971. .
8-3. Small, M.M. Marsh/Pond Sewage Treatment Plants. In: Freshwater
Wetlands and Sewage Effluent Disposal, D.L. Til ton, R.H. Kadlec
and C.J. Richardson (eds). University of Michigan, Ann Arbor,
Mi., 1976.
8-4. Small, M.M. Meadow/Marsh systems as Sewage Treatment Plants.
Brookhaven National Laboratory, Upton, N.Y., 1975.
8-5. Small, M.M. and C. Wurm. Data Report, Meadow/Marsh/Pond System.
Brookhaven National Laboratory, ;Upton, N.Y., 1977.
8-6. Small, M.M. Data Report, Marsh/Pond System. Brookhaven National
Laboratory, Upton, N. Y., 1976.
8-7. Boyt, F.L., S.E. Bayley and J. Zoltek, Jr. Removal of Nutrients
from Treated Municipal Wastewater by Wetland Vegetation. Jour.
Water Poll. Control Fed. 49(5):789, 1977.
8-8. Kadlec, R.H. and D.L. Tilton. Waste Water Treatment Via Wetland
Irrigation: Nutrient Dynamics. In: Environmental Quality
through Wetlands Utilization - Proceedings from a Symposium
Sponsored by the Coordinating Council on the Restoration of the
Kissimmee River Valley and Taylor Creek-Nubbin S'lough Basin,
Tallahassee, Fla.,.February 28-March.2j 1978. :
8-9. Tilton, D.L. and R.H. Kadlec. The Utilization of a Freshwater
Wetland for Nutrient Removal from Secondarily Treated Wastewater
Effluent. Jour. Environ. .Qual. 8(3):328, 1979..
8-10. Yonika, D..and D. Lowry. Feasibility Study of Wetland Disposal
of Wastewater Treatment Plant Effluent, Final Report.
Commonwealth of Massachusetts Water Resources Commission,
Research Project 78-104, 1979.
8-11. Dinges, W.R. Development of Hyacinth Wastewater Treatment System*
in Texas.. Paper presented at the Aquaculture Systems for
Wastewater Treatment Seminar, University of California, Davis,
Ca., September, 1979.
8-12. Wanielista, M.P. Stormwater Management, Quantity and Quality.
Ann Arbor Science Publishers, Inc.., Ann Arbor, Mi., 1978.
206 .
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8-13. East Central Florida Regional Planning Council. Orlando
Metropolitan Areawide Water Quality Management Plan 208, Vol. 3,
June, 1978.
8-14. Lynard, W.G., E.J. Finnemore, J.A. Loop and R.M. Finn. Urban
Stormwater Management and Technology: Case Histories.
EPA-600/8-80-035, August, 1980.
8-15. Sloey, W.E., F.L. Spangler and C.W. Fetter, Jr. Management of
Freshwater Wetlands for Nutrient Assimilation, In: Freshwater
Wetlands: Ecological Processes and Management "Potential, R.E.
Good, D.F. Whigham and R.L. Simpson (eds). Academic Press, New
York, N.Y., 1978.
8-16. Bay, R.R. Ground Water and Vegetation in Two Peat Bogs in
Northern Minnesota. Ecology 48:308, 1967. . ,. ,...,...
8-17. Vollenweider, R.A. Scientific Fundamentals o f Eutro phi cation of
Lakes and Flowing Waters, with Particular Reference to Nitrogen
and Phosphorus as Factors in Eutrophication. Tech.. Report OCED,
Paris, 1971.
8-18. Prakash, A. and M.A. Rashid. Influence of Humi-c"Substartces on
the Growth of .Marine Phyto plankton. Limnol. Oceanogr. 13.(4):598,
1968. :
8-19. Isirimah, N. 0. and D.R. Keeney. Contribution of Developed and
Natural Marshland Soils to Surface and Subsurface Water Quality.
Technical Completion Report Project Number OWRR A-049-WIS, Water
Resources Center, University of Wisconsin, Madison, Wis., 1973.
8-20. Turner, R.E., J.W. Day, Jr., M. Meo , P.M. Payonk, J.H. Stone,
T.B. Ford and W.G. Smith. Aspects of Land-Treated Water
Applications in Louisiana Wetlands. In: Freshwater Wetlands and
Sewage Effluent Disposal, D.L. T-11 ton, R.H. Kadlec and C.J.
Richardson (eds). University of Michigan, Ann Arbor, Mi., 1976.
8-21. Gosselink, J..G.., R.R. Miller, M. Hood and L.M. Bahr, Jr. (eds).
Louisiana Offshore Oil Port (LOOP): Environmental Baseline Study.
4 vols. LOOP, Inc., Harvey, La,.,1976.
8-22. Barada, N. and W.M. Partington, Jr. Report of Investigation of
the . Environmental Effects of Private Waterfront Canals.
Environmental . Information Center of the Florida Conservation,
Inc., Winter Park, Fla., 1972. . - ,
8-23. Stone, J.H., L.H. Bahr, Jr.. and J.W. Day, Jr. Effects of Canals
on Freshwater Marshes in Coastal Louisiana and Implications for
Management in Freshwater Wetlands. In: Freshwater ,Wetl ands and
Sewage Effluent Disposal, D.L. Til ton, R.H. Kadlec and C.J.
Richardson (eds). University of Michigan, Ann Arbor, Mi., 1976.
207
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8-24. Day, J.W., Jr., N.J. Craig and R.E. Turner. Cumulative Impact
Studies in Louisiana Coastal Zone: Land Loss. Louisiana State
Planning Office, Baton Rouge, La., 1976.
8-25. Blumer, K. The Use of Wetlands for Treating Wastes '-- Wisdom in
Diversity? In: Environmental Qual ity through Wetlands
Utilization. Proceedings from a Symposium Sponsored by the
Coordinating Council on the Restoration of the Kissimmee River
Valley and Taylor Creek-Nubbin Slough Basin, Tallahassee, Fla.,
February 29-March 2, 1978.
8-26. Kadlec, R.H. and D.L. Tilton. Monitoring Report on the Bellaire
Wastewater Treatment Facility. University of Michigan Wetlands
Ecosystem Group, University of Michigan, Ann Arbor, Mi., 1978.
8-27. Carlozzi , C.A. Enhancement of Ecologic and Aesthetic Values of
Water Associated with Interstate Highways. Publication to. 19,
Water Resources Research Center, University of Massachusetts,
Amherst, Mass., 1964. ;
8-28. Mitsch, W.J., H.T. Odum and K.C. Eivel. Ecological Engineering
through the Disposal of Wastewater .into Cypress Wetlands in
Florida. National Conference on Environmental Engineeri ng
Research, Development and Design. University of Washington,
Seattle, Wa., 1976.
8-29. Sutherland, J.C. and F.B. Bevis. Reuse of Municipal Wastewater
by Volunteer Freshwater Wetlands. Proceedings, Water Reuse
Symposium, Vol. 1, Washington, O.C., March, 1979.
8-30. Williams, T»C. and J.C. Sutherland. Engineering, 'Energy and
Effectiveness Features of Michigan Wetland Tertiary Wastewater
Treatment Systems. Paper presented at the Aquaculture Systems
for Wastewater Treatment Seminar, University of California,
Davis, Ca., September 1979.
8-31. Personal communication, Peter Koos. Ea-st Bay Regional Park
District, May 29, 1981.
8-32. Demgen, F.C. Wetlands Creation for Habitat and Treatment - At
Mt. View Sanitary District,; California, Paper presented at, the
Aquaculture Systems for Wastewater Treatment Seminar, University
of California, Davis, Ca., September, 1979.
8-33. Cederquist, N. Waste Water Reclamation and Reuse Pilot
Demonstration Program for the Suisun Marsh - Progress Report,
March 1977. U.S. Bureau of Reclamation, Sacramento, Ca., 1977.
8-34. Hartl and-Rowe, R.C.B. and P.B. Wright. Swamplands for Sewage
Effluents: Final Report. Environmental-Social Committee
Northern Pipelines, Report ND. 74-4. Information Canada Cat. to.
R72-13174, #QS-1553-000-E-A1, Canada, May, 1974.
208
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8-35. Stowell, R., R. Ludwig, J. Colt and 6. Tchobanoglous. Toward the
Rational Design of Aquatic Treatment Systems. Paper presented at
the ASCE Spring Convention, Portland, Ore., April 14-18, 1980.
8-36. Kuenzler, E.J. and H. L, Marshall. Effects of Nbsquito Control
Ditching on Estuarine Ecosystems. Water Resources Research
Institute of the University of North Carolina, Report No. 81,
1973.
8-37. Lasalle, R.N. and K.L. Knight. Effects of Salt Marsh
Impoundments on Mosquito Populations. Water Resources Research
Institute of the University of North Carolina, Report No. 92,
1974.
8-38. Lasalle, R.N. and K.L. Knight. The Effects of Ditching on the
Mo.squito Populations in Some Sections of Juncus Salt Marsh in
Carteret Co unty, -North Carol ina. ' Water Resources Research
Institute of the University of North Carolina, Report No. 82,
1973. . .
8-39. Seabrook, E.L. The Correlation of Mosquito Breeding to Hyacinth
Plants. Hyacinth Control Jour. 1:717, 1962.
8-40. Hanna, G.D. Gray Lodge Wildlife Area (California) - Exploratory
Studies of Mosquito Production and Control. In: Proceedings and
Papers of the Forty-Seventh Annual Conference of the California
Mosquito and Vector Control Assoc., Inc., 1979.
8-41. Hanna, G.D. Recommendations for Control of Aedine Mosquitos at
Gray Lodge Wildlife Area. University of California Graduate
Group in Ecology, Davis, Ca., (No date).
8-42. Alameda County Mosquito Abatement District. Standard
Recommendations to Prevent Mosquito Problems Associated with
Freshwater Marshes of Alameda County. (No date).
8-43. Lihde, A.F. Techniques for Wetland Management. Research Report
No. 45, Department of Natural Resources, University of Wisconsin,
Madison, Wis., 1969.
8-44. Middlebrooks, E.G. Aquatic Processes Assessment. Paper
presented at the Aquaculture Systems for Wastewater Treatment
Seminar, University of California, Davis, Ca., September 1979.
8-45. Tchobanoglous, G. Wetland Systems for Wastewater Treatment in
Cold Climates: An Engineering Assessment. Prepared for the U.S.
Army Cold Regions Research and Engineering Laboratory, Hanover,
N.H., 1979.
209
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SECTION 9
MOHITORING AND RESEARCH NEEDS
Extremely -encouraging results have been reported from the studies and
investigations reviewed in this report. Investigations of individual
plant species have demonstrated measurable capabilities to remove
pollutants from water. Similarly, physical and chemical processes known
to occur in wetlands have substantial pollutant removal value. In the
limited number of case studies on wetlands renovation of polluted
waters, several showed excellent results. Others produced mixed
results, often reflecting lack of management or improper loading of a
wetland, due to lack of understanding of wetlands processes, rather than
an inherent failure of the processes. Thus, if any single research
objective for further wetlands studies were to be high! ighted, it would
be to develop an understanding of the 1nter.pT.ay of all wetland
components in the removal, assimilation, or release of pollutants. Much
of th-e previous work on wetlands, or vegetative systems, is
characterized by a piecemeal approach with Tittle attention to system
dynamics. ,
Much additional work remains to be performed before limited objective
questions can be answered, much less, a full understanding achieved about
wetlands systems. Recommended areas for monitoring and research are
presented in this section.
WETLANDS INVENTORY
Over the years, a number of efforts have been made by various agencies
to identify wetlands. Appendix B contains a map and state-by-state
listing of state and local wetland surveys conducted between 1965 and
1975 [9-1]. This Information was compiled for the U.S. Fish and
Wildlife Servieei prior to embarking upon its current nationwide
inventory of wetlands [9-2]. This massive effort is intended to
identify wetlands arid establish a common classification system grouping
ecologically similar habitats. In relation .to water quality and
wastewater treatment -In wetlands, this inventory will be of great aid in
establ ishing uni formity in concepts and terminology, .and ultimately in
improving, understanding of wetland functions and capacity.
In addition to this forthcoming inventory (only portions of which are
currently available) there is a need to obtain more detailed
characterization of potential wetland treatment sites. Greatest
attention should be focused on the hydrologic regime to build a more
functional picture of particular wetlands [9-3],
210
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MONITORING
In addition to the locations identified in this report, numerous
situations exist where pollutants are being discharged to wetland
systems, tore extensive monitoring of these existing systems should be
undertaken for study durations of two to five years [9-4], Factors
requiring consideration include:
(1) Understanding the controlling geology;
(2) Modelling the hydrologic budget, particularly with regard
to surface-ground water relationships;
(3) Sediment profiles and analysis;
(4) Intensive water quality analysis, including spatial and
temporal differences;
(5) Cha.ra.cteri zi ng: the ..vegetative community and litte.r .
components.
In addition to.monitoring existing discharges, questions related to the
ability of wetlands to recover from pollutant application can be
explored through the selection of sites.where pollutant.discharges have
recently been terminated.
Long-term (10 years) monitoring of the most promising wetlands treatment
concepts should be carried out in a range of geographical settings to
observe equilibrium effects [9-4], In so doing, it will be incumbent
upon the investigators to very carefully document changes in the natural
system that could signal future problems.
RESEARCH ISSUES
A number of issues can be identified for future research. These issues,
or questions, .relate to.-both.a.ir.. understanding of the fundamental
processes involved and to development of management techniques.
Vegetative/Biological System
Most previous studies on vegetative practices for pollutant removal have
focused on upland systems, such as crop irrigation, on monocultures in a
controlled envi ro-nment, or upon single plant species. Mare studies are
now needed to address vegetation and other members of the ecological
system in the context of wetlands. Specific topics recommended for
research include:
(1) Definition of effects on higher level wetland biota as a
result of adding pollutants; '
211
-------
(2) Possibil ity of transfer of heavy metals into the food
chain by aquatic plants;
(3) Trace element uptake of various .pi ant species during
different parts of the growing season;
(4) Effect of plant type and biomass on degree of treatment;
(5) Nutrient uptake and release by plant litter.
Hydrolo gic .-System
The correlation between fluid movement and physical Or chemical
poll utant 'removal -processes has been extensively studied and is
reasonably well understood for controlled environments, such as the
primary settling tanks or chlorine contact chambe'r-s in wastewater
treatmentfacilities; In wetlands, where many factors will interrelate
to produce a unique situation for every site,-understanding and control
of the system's hyd'raul ics is, not "as well developed. The .following
research "topics wo-uld help "reduce this problem: :
(1) Development of quantitative information about the
'hydrodynamics of different -wetla'ad types, including
natural and polluted water flows; .
(2) Cl-assification of the relationship between water movement
in a marsh and physical or chemical pollutant removal
processes;
(3) -Effect of detention'time on treatment efficiency for
Different wetland types.
SystenuRerformance
The follo.wing research topics wo-uld extend previous narrowly focused
study results into the more'complex interrelationships among pollutant
processes in wetlands: : 'V
.(1) Determination of.'.icapactt'l-es arid functio-ria-T longevity of . ....
natural systems;
(2) Determination of interaction and relative importance of
wet 1 and -ch'aracteri sties in achi eving wastewater
renovation;
(3) Influence of other biological and microbiological factors
on wetland performance;
(4) Effect of bottom substrates on pollutant uptake by
vegetation and degree of treatment;
212
-------
(5) Effect of grass/wetland configuration on pollutant
removals.
Theory of Wetlands Treatment
Closely related to an understanding of wetlands as a complex treatment
system is the development of a theoretical basis for explaining system
behavior. Just as the Mo nod and Michaelis-Menten relationships for
organism growth and food usage formed an early basis for sanitary
engineering design and operating principles, similar theoretical
foundations need to be laid for wetlands utilization. The following
topics would help achieve this goal:
(1) Definition of removal kinetics in terms of wetland type,
vegetation, detritus, climate and management practices;
(2) Development of an ability.to measure and forecast
appropriate loading factors and capacities of wetlands.
Wetlands Management . :v: : '' '.','
Heretofore, wetlands use for po-t.l.utant removal ha.s been, primarily,
haphazard or incidental with little control extended over factors that
could significantly alter--pollutant, remova-1 efficiencies',or wetland
response. In some areas, such as management of wetlands vegetation, far
less is known as compared to manipulation o-f hydraulics, for which: some
experience can be borrowed from conventional wastewater treatment
technology. The following research topics would serve to produce the
information necessary for the development of wetlands management
procedures:
(1) Development of methods to manage .vegetation in wetlands;
(2) Effects of vegetation management, such as harvesting, on
nutrient and pollutant uptake; -
(3): Development of seasonal flow manipulation techniques for
maximum pollutant removal;
(4) Understanding of the effect of water level control on
changes in biological pollutant removal and water
quality;
(5) Determination of costs and benefits of wetlands treatment
of stormwaters and treated municipal wastewaters;
(6) Options or procedures for the reclamation or renovation
of wetlands damaged by previous excessive pollutant
loadings.
213
-------
REFERENCES
9-1. U.S. Fish and Wildlife Service. Existing State and Local Wetlands
Surveys (1965-1975),. Prepared by Martel Laboratories, Inc.;
1976*
9-2. Cowardin, L.M., V. Carter, F.C. Golet and E.T. LaRoe.
Classification of Wetlands'and Deepwater Habitats of the United
States. Prepared for U.S. Fish and Wildlife Service, Publication
FWS/OBS-79/31, December, 1979.
9-3. Gosselink, J.G. and R.E. Turner. The Role of Hydrology in
Freshwater Wetland Ecosystems. In: Freshwater Wet!ands:
Ecological Processes and Management Potential, R.E. Good, D.F.
Whigham and R.L. Simpson (eds). Academic Press, New York, N.Y.,
1978. . . -,...
9-4. Yonika, 0. and D. Lowry. Feasibil ity Study of Wetland Disposal
of ' Waste.wa.ter Treatment Plant .Effluent., Fi ha 1 :'Re po rt.
Commonwealth of Massachusetts Water Resources Commission,
Research Project 78-104, 1979.
214
-------
APPENDIX A
VEGETATION TYPES
The wetland and upland ecosystems are dominated by various
characteristic species of vegetation as discussed in Section 2 of this
report. These vegetation types are adapted to various environmental and
climatic conditions, and population characteristics can vary by
geographic distribution. Thus, the same or similar plant species can
exhibit narrow tolerances in one area and yet in another climate, such
as coastal or desert, the population may withstand more extreme
conditions.
Wetland vegetation types can be divided into three categories:
(1) Emergent - rooted in sed.iments and growing through the
water column above water level (Table A-l and Figure
A-l); . : . ./
(2) Floating - aquatic roots with plant parts partly
submerged or fully exposed on the water.surface (Table ..
A-2 and Figure A-2);
(3) Submerged - rooted in sediments or aquatic, with all
plant parts growing within the water column (Table A-3
and Figure A-3).
In emergent and floating vegetation types, where photo synthetic activity
occurs mainly above the water surface, uptake of nutrients, minerals and
trace contaminants occurs primarily through the root system. In
submerged vegetation, which often has weak root systems, photosynthesis
occurs underwater and uptake of compounds can occur directly through
stem and leaf tissue as well as through the roots.
A-l
215
-------
TABLE A-I. EMERGENT VEGETATION TYPES, CHARACTERISTICS AND ENVIRONMENTAL TOLERANCES
ro j>
av ro
Vegetation.
type
Cattails
(Typha sppO
Reeds
(Phragmltes
sppTJ
Rushes
(Juncus spp.)
(over 200
SPP-)
Sedges
(Cajrex spp.)
Sedges -
nutsedges
( Cyperus spp,)
Aboveground
height
0.7-2.7 m
spreading
mats and^
thick
stands
3-4 m-
open
stands
0.02-1.5 m
dense
clumps :
0.1-1 m
in clumps
8-50 on
Belpwground
characteristics
Woody rhizomes
comprise 45-601
of plant btomass;.
lives 1H-2. yrs.
growth up to
100 cm/yr.
Dense, rhizomes
Mve 3-6 yrs. -
viable to 9 yrs.
in dry soils;
leafy stolons up
to 9 m long.
Creeping
rhizomes
Creeping- .'.'
rhizomes.
Creeping *
rhizomes,
reproduction
from tubers
and bulbs
Plant occurrences or tolerances
Soili pH- (water)
Mud and slit- 4.7.10.0
with- 25 on wide range
detritaV +
humtc layers;
organic con-
tent up to
331..
Clay, sand Wide range
or silt under 2.0-8.5
swampy condi-
tions; organic
content 6-
541
Organic soils No data
(no data on
content)
i1
Muck or clay 4.9-7.4
With up to
10 cm detrital
layer; up to
45% organic
content
flefer to 7.1 optimum.
Carex range of 3-
8
Salinity
0.15 ppt
(up to 25
ppt, some
spp.)
0-10 ppt
optimum;
up to 40
ppt some
spp.
0-14 ppt
(up to 35
ppt some
spp.)
0-.4 ppt
(freshwater
only).
0-..4 ppt
(freshwater
only)
Water depth
0.2-1 m.
60-80 cm
optimum;
ranges from
-.3m to
4m
At 'or just
below soil
surface.
-.05 to
.95 m
At or Just
above ground
surface (-.05
to .3m)
Air temp*-
9-31°C
seed germ.
at 18-24 C
11-32°C
Seed germ.
at 10-30°C.
16-26°C.
15-21°C
(range of
14-32°C)
32°C opti-
mum (range
of 16-
45°C)
Comments and references
T. domingensts. (coastal * Inland
growth inhibited at 26 ppt. salinity.
California population stunted. at
12 ppt; T. augustifolia ranges from
0.2-25.5 ppt, optimum growth. at
22.5 ppt); T. latlfolia
does not occur in coastal bays -
probably less salt tolerant than
T. auqustifolia. (.IA.B 7; A o
12, 16. 17, 46. 50).
P. communis of widest distribution
and most study; pioneer in early
plant succession, but competes
poorly; tolerates little water
movement; roots can metabolize
anaeroblcally, so reeds can
grow in highly reduced muds. (A-l,
7. 8. 9. 10. 11. 36. 37. 47, 48.
49)
Can withstand wave action; found
In fresh, brackish & salt marshes;
J. balticus tolerates salinities
of 16-24 ppt; limitations for
coastal spp: J. marittmus 14 ppt;
J. balticus and J. gerardii 16-17
ppt; J. marltlmus requires <7 ppt
for germination. (A-18, 19, 20.
21 . 50)
Carex reproduces almost entirely
by vegetative propagation. Unlike
other emergent* , Carex buds fora
and shoots emerge year-round.
Carex competes poorly with other
species U-7, 13. 15, 29, 33, 38.
46. 52. 53)
Nutsedge roots enhance denitri-
fying bacteria activity - decreas-
ing nitrogen availability to
other plants; thrives in tem-
perate climates (A-24, 25. 31)
* During growing season.
(continued)
-------
TABLE A-l. (continued)
CO
Vegetation Aboveground Belowground
type height t characteristics
Sedges - 0.3-3 m Thick, creeping
bulrushes rhizomes
(Scirpus
spp.)
Canarygrasses 30 cm. Creeping
(Phalaris flower rhizomes
spp.) spikes
0.6-2 m
Cordgrasses Short Scaly
(Spartina forms: 0.3- rhizomes
spp. ) 0.4 m, tall
forms: 1.2-
2 ra
Pickleweed 0.2-0.6 ra Thick spreading
(Salicornia dense, roots 2-5 mn
sppf) erect thick
clumps
Plant occurrences or tolerances
Soil pH (water) Salinity Mater depth
Refer to 4-9 4-20 ppt Minimum
Carex optimum, 5-10 en,
0-32 ppt maxiouB
range depth var-
iable with
species
Silt loam 6.1-7.5 No data. At or just
(no data on but gen- below soil
content) erally surface
freshwater
only
Sandy 4.7-7.8 9-34 ppt -.15 to
substrate 7 m
-
Mud, clay 3.9-8.0 .4-34 ppt -.U to
with low (tolerates .3 m
organic up to
content 80- ppt)
Air temp*
17-28°C,
varies with
geograph-
ical loca-
tion.
15-25°C
(up, to
30°C some
SPP.)
Seed germ.
at 18-
35°C.
12-29°C
Seed germ.
ato18'
35°C.
11-32°C
Comments and references
Water level 1s critical for
Scirpus success: S. olneyi
-.75 cm to 6 m; S. acutus
and S. heterochaetus up to
2 m; S. validus i\ ra; Scirpus spp.
at Suisun Marsh, Calif. 0.75-
25 cm. All Scirpus require
freshwater for germination;
S. acutus tolerates salinities
to 32 ppt; S. validus »
S. heterochaetus restricted to
lower salinities; S. olneyi
Inhibited by >20 ppt; S. robustus
thrives below 22 ppt. (A-2,3,
8,9,12,39,50,54)
Generally an upland grass that
tolerates high moisture, high
water tables and occasional
innundatlon. P. arundinacea
(reed canarygrass) is most
commonly found and subject to
Study. (A-4. 14.27 ,28, 30, 32.
35,51)
S. alterniflora tolerates salin-
ities to 32 ppt; S. foliosa
and S. pagens only to 18 ppt;
roost Spartina require low
salinity ( 4-8 ppt) for germina-
tion. Spartina grows best in
freshwater, but cannot compete
with cattails and rushes; common
in salt marshes. (A-5.22,23,26,
34.40.41,42,43,44)
Found in brackish and saltwater
marshes; requires saline con-
ditions for growth; can with-
stand seasonal drying and alkaline
conditions. (A-55)
* During growing season
-------
Figure A-l. Emergent Aquatic Vegetation3
ro ;>
CO *>
1/8
life-size
1/16
life-size'
Broadleaf Cattail
(Typha latifolia)
1/4
life-size . two times.
life-size
seed
Common Reed
(Phragmites communis)
life-size
seed
1/16
ffe-size
Baltic Rush
(Juncus bolticus)
(continued)
-------
Figure A-l. (continued)
ro 3=
^ I
-------
Figure A-l. (concluded)
rvi >
ro i
O cr>
1/6,
life-size
t;/o times
life-size
seed
*
2/3 **
1 ife-size seeds
Lake Sedge
(Carex rtparia)
seeds
two times
life-size
Softstem Bulrush
( Scirpus vqlidus )
: i/6
ife-size
two time
Jife-si
Alkali
Bulrush
1/6
life-
( Scirpus robustus )
1/6 || Slough Sedge
life-sizj (earex trichocarpa)
Redroot Cyperus
( Cyperus erythrorhizos)
a. Source: derived from reference A-l19
-------
TABLE A-2. FLOATING VEGETATION TYPES, CHARACTERISTICS AND ENVIRONMENTAL TOLERANCES
ro
ro
Vegetation
type :
Water hyacinth
(Eichhornla
crassipesT~
Duckweed
(Lemna spp. ,
Splrodela spp. ,
wyiff
-------
ro i
re CO
Figure A-2. Floating Aquatic Vegetation3
life-size
Water Hyacinth
( Eichhornia crassipes )
Duckweed
life-size
( Lemna spp.)
life-size
( Spirodela spp:)
;O
two times .
life-size
Watermeals
(Wolffia spp.)
two times
life-size .
Water Velvets
(Azolla spp.)
a. Source: derived from reference A-119.
-------
TABLE A-3. SUBMERGED VEGETATION TYPES, CHARACTERISTICS AND ENVIRONMENTAL TOLERANCES
ro 3>
ro i
OJ lO
Vegetation type
Pondweed
IPotamogeton spp.)
90-100 species
- . : ' '. -
Clodea
(£lodea canadensls,
E. occidental 1$.
E. densa)
Coon tail
(Ceratophyllun
demersum, ~
C. ecMnatum)
Uatermitfoil
(Myriophylluni
spp.) . ^
Morphology
Plants with thread-like
to ribbon-like leaves
scattered singly on
flexible underwater stems;
. well -developed root system
comprises up to 49% of
plant mass.
Branched stems 5-15 cm;
covered thickly with .5-
1.5 cm long leaves;
found in groups of 2-6 de-
pending on spp.; well-
developed root system.
Many-branched bare stalk
1-2 m long;. brittle,
forked leaves with small
thorns; found in clusters
of 5-12 from central
nodes.
Slender stems and few
branches; divided leaves
grouped in whorls.
Plant occurrences
pH Water temp.
6.3 to 10 10to35°C
45° lethal
23-26°C
req. for
6.5-10 10to25°C
2to18°C
optimum for
P uptake
4.0 to 8.7 10to20°C
optimum optimum 18°
7.1 to 8.0 min. 5.5°
(for one
species). .
5 to 10 0.2to30°C
1 optimum 15
to25°C
or tolerances
Vlater depth
1 to 7 m
max. 10 m
P. pectinatus
opt. =30-46 cm
1 to 7 m
max. 12 m
No data,
probably
Similar to
El odea
1 to 3 m
max. 5 ro
min. 50-80 cm
Salinity
0 to 15 ppt
max. 19 ppt
0.2 - 3.6 ppt .
IE. canadensls)
9.Z - 14.4 ppt
(E. nuttallll)
,0 to 3.8 ppt
0 to 15 ppt .
optimum 0.83-
3.33 ppt
Corments and references
Reproduces by seeds, winter buds,
rhizomes or tubers; tubers are a
major waterfowl food; cosmopolitan
90-100 species; P. pectinatus most
brackish water and pollutant toler-
ant; P. crispus, P. pusillus, P.
perfoliatus and P. natans also
tolerate brackish water and pol-
luted habitats. (A-83 81,89,91,92,
93.94.99.100.102,105,106.109,110.
112,114,115,117)
Reproduces by fragmentation; over-
winters as winter buds; best
adapted for calcareous Inland
lakes, ponds, slow-moving streams
and slightly brackish coastal waters;
good water oxygenator; marl deposits
are common. (A-82, 83, 85,89, 94, 100. 106,
108,113,116)
Reproduces by winter buds and
fragmentation; requires still or very
slow moving water; aquatic birds
eat fruits; upright growth in spring;
broad floating habit in summer/fall.
(A-83. 90, 98, 100, 106, 107, 11 1,1 16)
Reproduces by fragmentation and/or
formation of winter buds; cosmopolitan
45 species. (A-83,86,87,88.89;92,93,
94.95.96,97.100.101,103.104,111.118)
-------
Figure A-3. Submerged Aquatic Vegetation'
1/3
1/3 | life-size
life-size
1/31,
life-site
two times
life-size
Sago Pondweed
( Potamogeton pectinatus)
1/2 life-size
two times
life-size
Curly Pondweed
( Polamogeton crispus )
two times
life-size
1/3
life-size
Floaling Pondweed
( Potamogeton natans) ,
-------
Figure A-3. (conclusion)
2/3 life-size
Common Elodea
( Elodea canadensis)
2/3
'life-size
seed
i CoontaM
(Ceratophyllum demersum)
3/4 life-si
Parrotfeathe
(Myriophyllm
brasiliense)
( Myriophyllm
a. Source: derived from reference A-119.
-------
REFERENCES
A- 1. Nikolajevskij, V.G. Research into the Biology of the Common Reed
(Phragmites cpmmunis Trin.) in the U.S.S.R. Folia. Geobot.
Phytotax., 6:221-230, 1971.
Ai 2. Sipple, W.S. A Review of the Biology, Ecology, and Management of
Scirpus olneyi. Vol. II: A Synthesis of Selected References.
Water Resources Administration, Department of Water Resources,
Annapolis, Md., 84pp.., 1979.
A- 3. Sipple, W.S. A Review of the Biology, Ecology, and Management of
Scirpus olneyi. Vol. I: An Annotated Bibliography.of Selected
References. Water Resources Administration, Department of Water
Resources, Annapolis, Md., 96 pp., 1978.
A- 4. Gross, C.F.. and G.A.- Jung. Magnesium, Ca/, and X Concentration in
Temperate-Origin Forage Species as Affected by Temperatureand ,Mg
Fertilization. Agron., Jour., 70(3):.397-403, 1978.
A- 5. Seneca, E.D. Germination Response to Temperature and Salinity of
Four Dune Grasses from the Outer Banks of North Carolina.
Ecology, 50:45-53, 1969.
A- 6. McNaughton, S.J. Ecotype Function in the Typha Community-Type.
Ecol. Monogr., 36:298-325, 1966.
A- 7. Sp.e.nce, D.H.N. Factors. Controlling the Distribution of
Freshwater Macrophytes with Particular Reference to the Lochs of
Scotland.- Jour. Ecql., 55:147-170, 1967. ..,.
A- 8. Dykyjova, D. and.. B. Ulehlova., Structure and Chemistry of the
Fishpond Bottom. In: Pond littoral Ecosystems: Structure and
: Functioning, D.~~Bykyjova and J. Kvet (eds), (pg. 141-152)
Springer-Verlag, New York, N.Y.,, 1978.
A- 9.; Philip, C.C. and R.G. Brown., Ecologica.1 Studies of
Trans.i.tion-Zone Vascular PTants in South River, Maryland. Ches.
Sci., 6(2):73^-81, 1965.
A-10. Gorham, E.. and W.H. Pearsal.l. Production Ecology. Ill: Shoot
Production in Phragmites in Relation to Hab.itat. Oikos
7(11):206-214, 1956.
A-ll. Haslam, S.M. The Performance of Phragmites communis Trin. In
Relat.io.n to Water-Supply. Amer. Bot., 34:867-877, 1970.
A-12. Lathwell, D.J., D.R. Bouldin and E.A. Goyette. Growth and
Chemical Composition of Aquatic Plants in Twenty Artificial
Wildlife Marshes. N.Y. Fish Game Jour., 20:108-128, 1973.
A-12
226
-------
A-13. Van Der Valk, A.G. and C.B. Davis. Changes in the Composition,
Structure, and Production of Plant Communities along a Perturbed
Wetland Coenocline. Vegetatio, 32(2):87-96, 1976.
A-14. Gomrn, F.B. Growth and Development of Meadow Plants as Affected
by Environmental Variables. Agron. Jour., 70(6):1061-1065, 1978.
A-15. Corns, W..6. Influence of Time and Frequency of Harvests on
Productivity and Chemical Composition of Fertilized and
Unfertilized Awned Sedge. Can. Jour. Plant Sci., 54:493-498,
1974.
A-16. Shekov, A.G. Effect of Salinization on Hydro ma crophytes of Kuban
Limans. Sov. Jour. Ecol., 5(5):450-454, 1974.
A-17. U.S. Department of Agriculture. Management and Uses of Cattail
, (Typha dojningensis) in California. Soil Conservation Service,
tf.:S. -Department of Agriculture, Berkeley, Ca., 2ppk, 1972.
'A-18. Cavatfert, A.J. and A.H.C. Huang. Evaluation of Proline
Accumulation in the Adaption of Diverse Species of .Marsh
'Ha-1-o.p.h-ytes to. .the- Sal Ine Environment. Amer. Jour. "Bot. ,
66(3}:307-312, 1979.
A-19. Cavalieri, A.J. and A.H.C. Huang. Proline Accumulation in Salt
Marsh Halophytes Exposed to Increasing Salinity. Plant Physio! ,
61(4):6, 1978 (Abstract only).
*
A-20. Clarke, L.D. and N.J. Hannon. The Mangrove Swamp and Salt Marsh
Communities of the Sydney District. III. Plant Growth in
. Relation to Salinity and Waterlogging. Jour. Ecol.,
58(2):351-369, 1970.
A-21. Rozema, J. and B. Blom. Effects of Salinity and Inundation on
the Growtil of Agrostis stolonifera and Juncus gerardi i . Jour.
Ecol., 65:213-222,. 1977^ "~ ~~ .
A^22. Brbome, S.W., W.W. Wopd.no use and E.D. Seneca. ; The Relationship
A . '.. ,of Miinera-1. .Nutrients to Growth of Spa rt i na a 1 1 e r n i f 1 o ra in North
Carolina: I. Nutrient Status of Plants and Soils in Natural
Stands. .Soil Sci. .Amer., Proc., 39(2):?95-307, 1975.
A-23. Moorinj, M.T. , A.W. Cooper and E.D. Seneca. Seed Germination
Response: .and fvidence for Height Ecoph.enes in Spa rt i_na
a 1 term' flora from North Carolina. Amer. Jour. Bot., 58(l):48-55,
" ' - '"'
Al/rAli, F.A., SVR;A. Shamsi and S.M. Hussain. Sprouting and
Growth of Purple Nutsedge, Cyperus rotundas, in Relation to pH
.and Aeration. Phys.iol. Plant., 4.4 (4): 373-376, 1978.
A-13
227
-------
A-25. Palmer, R.D. the Effect of Temperature, pH and Nutrition upon
the Germination and Growth of Nutsedge (Cyperus rotundus L.).
Proc. Southern Weed. Conf., 14:479, 196U
A-26. Linthurst, R.A. The Effect of Aeration on the Growth of Spartina
alterni flora Loisel. Amer. Jour. Bat., 66(6 ): 685-691, "
A-27. Dean, J.R. and K.'W. Clark. Nitrogen Fertilization of Reed
Canarygrass and Its Effects on Production and Mineral Element
Content.. Can. Jour. Plant Sci., 52:325-331, 1972.
A-28. Niehaus, M.N. Effect of N Fertilizer on Yield, Crude Protein
Co-ntent , and in vitro Dry-Matter Disappearance on Phal a ri s
arundinaceae L. Agron. Jour., 63 (2): 793-794, 1971.
A-29. Baker, J.M. Seasonal Effects of Oil Pollution on Salt Marsh
Vegetation. Oikos, 22:106-110, 1.971.
A-30. Allrnson, D.W. Influence of Simazine on Yield and Quality
Components of Reed Canarygrass. Agron. Jo.ur.i 64:530-535, 1972.
A-31. Volz, M.G. Infestations of Yellow Nutsedge in Cropped Soil:
Ef f ects on! So i 1 Nitrogen Availability to the Crop and on
Associated N Transforming Bacterial Populations. Agro-Ecosys . ,
3:313-323, 1977.
A-32. Bole, J.B. and R.G. Bell. Land Application of Municipal Sewage
Waste Water: Yield and Chemical Composition of Forage Crops.
Jour. Environ. Qua!., 7(2):222-226, 1978.
A-33. Jones, R.^ Comparative studies of Plant growth, and Distribution in
Relation, to Waterlogging. VIII: The Uptake of Phosphorus by Dune
,: and Slack Dune Plants. Jour. Ecol., 63 (I): 109 -116, 1975.
A-34. McGdvern, T.C;, L.J. Laber and B.C. Gram. Characteristics of the
Salts Secreted by $pat:tina aHerni flora Loisel and Their Relation
to Estuafine Production; Estuar. Coastal Mar. Sci., 9:351-356,
...... 1979... : ;-.;.;v: . -' .' : -; ..' ' '.. '
A-35. Sidle, R.C., J.E. Hook and L.T. Kardos. Heavy Metals Appl ication
and Plant Uptake in a Land Disposal System for Wa'stewater. Jour.
Environ. Qua!., 5(1):97-102, 1976.
A-36. Haslam, S.M. Community Regulation in Phragmites communis Trin.
II. Mixed Stands. Jour. Ecol., 59(l):75-88, 1971.
A-37. Mochnacka-Lawacz, H. Description of 'the Common Reed (Phragmites
communis Trin.) against Habitat Conditions., and Its Ro.le in the
Overgrowing of Lakes. Ekol.ogia Polska, 23(4):545-371, 1975.
A-14
.228
-------
A-38 Bernard, J.H. Production Ecology of Wetland Sedges: The Genus
Cafex. Polskie Archiwum Hydrobiologii,, 20(1):207-214, 1973.
A-39. Smith, S.G. Ecology of the Scirpus lacustris Complex in North
America. Polskie Archiwum Flydrobiol., 20(1):215-216, 1973.
A-40. Pamatmat, M.M. and H.R. Skjoldal. Metabolic Activity, Adenosine
Phosphates and Energy Charge of Below Ground Biomass of Juncus
roemerianus Scheele and Spartina alterniflora Loisel. Estuar.
Coastal Mar. Sci., 9:79-90, 1979.
A-41. Provost, M.W. Salt Marsh Management in Florida. In: Tall Timbers
Conference on Ecological Animal Control by Habrtat Management,
Proceedings Number 5. (pg. 5-17) Tall Timbers Research: Station,
Tallahassee, Fla., 1974.
A-42. Ranwell, D.S. Spartina Salt Marshes in Southern England. Ill:
Rates.of Establishment., Succession and Nutrient Supply at
Bridgwater Bay, Somerset,'-Jour. Ecol., 52(4):95-l;05, 1964.
A-43. Shea, M.L., R.5. Warren and W.A. Nieri:ng« Biochemical and
Transplant Studies of the Growth Form of Spartina a 1 term'flora on
Connecticut Salt .Marshes. Ecology, 56:461 ,-.466, 1973,: .
A-44. Valliela,, I.., J.M.. Teal and W.G. Deu.ser... The Nature.of Growth
Forms in the Salt Marsh Grass Spartina alterniflora. Amer.
Natur., 112(985):461-470, 1978.
A-45. Leek, M.A. and K.J. Graveline. The Seed Bank of a Freshwater
Tidal Marsh. Amer. Jour. Bat., 66(9):1006-1015, 1979.
A-46. Van der Valk, A.6. and C.B. Davis. A Reconstruction of the
Recent Vegetational History of a Prairie Marsh, Eagle Lake, Iowa,
from Its Seed Bank. Aquat. Bot., 6:29-51, 1979.
A-47. Haslam, S.M. The Development and Emergence of Buds in Phragmites
commum's Trin. Ann. Bot., 33:289-301, 196,9.
A-48.. Haslam, S.M. The Development-of Shoots in Phragmites communis
Trin. Ann, Bot., 33:695-709, 1969. " "~~. : .
A-49. Haslam, S. Some Aspects of .the Life History and Autecology of
Plrra gmi tes co mmun i s Tr i n . A Review. Polskie Archiwum
Hydrobiologii, 20(1):79-100, 1973.
A-50. Mall, R.E. Soi l-Water-Salt Relationships of Waterfowl Food
Plants in the Suisun Marsh of California. Wildlife Bulletin No.
1, Cali fornia Department of Fish and Game, Sacramento, Ca,, 59
pp., 1969. .
A-15
229
-------
A -51. Byers, R.A. and K.E. Zeiders. '. Effect of .Spray Irrigation with
Municipal Sewage Effluent on the Cereal Leaf Beetle and the Fruit
Fly Investing Reed Carnarygrass . Jour. Environ. Qual.,
5(2): 205-206, 1976. :. ...... ' ; '. .
A-52. Auclair, A.N.D. , A. Bouchard and J. Pajaczkowski . Productivity
Relations in a Carex-Dominated Ecosystem. Oecology (Berl.),
26(1):9-31, 19767" .
A-53. Parvu, C. and E. Ene. Contributions to the Investigation of
Macrophytic and Phytopl anctonic Primary Productivity from
Peat-Sphagnicol Marsh Manta (Romania) in 1976. Archiv. Hydrobiol .
Suppl., 52 (2-3): 229-240, 1978,
A-54. Small, E. and J.D. Gaynor. Comparative Concentration of 12
Elements in Substrates and Leaves of Scirpus and Other Aquatic
Plants. Can. Field Nat.* 89(1): 41 -46,. 1975. , (
A-55. Association of Bay Area Governments. .-. Treatment .of Stormwater
Runoff by a Marsh/Flood Basin - Interim Report. . Berk^T'ey', C:a . ,
August, 1979.. . .. : .. ; ; :: ,
A-56. Penfound, W.Ti and T.T. Earle. The Biology of Water Hyacinths.
Ecol. Monographs, 18 (4) .-447-472, 1948. ".'...
A-57. Hillman, W.S. The Lemnaceae, or Duckweeds: A Review of the
Descriptive and Experimental Literature. Bot. Rev., 27:221-287,
1961.
A-58. Ashton, P.J. and R.D. Walmsley* The Aquatic Fern Azbll a and its
. Anabaena Symbiont. Endeavour, 35(124):39-43, 1976, : . - ,:
A-59. Moorse, A.W. AzoTla: Biology and Agronomic Significance. Bot.
Rev., 35:17-34, 1969, ,
A-60. Batanouny, K.H. and A.M. El -Finky . The .Water.. Hyaci nth
( E i c hhq r ni a C ra s s 1-pes;) in the Nile Systems, Egypt. Aqtia't. 8dt.,
1:243-252, ~
A-61. Hamouda, M.A. The Water Outlay by E-ichlmrni.a cra-sslipes an:d
Observations on the Plant C h em i c a 1 .Co n t r o T ." P'h y t o n ,
13(1 -2): 97-106.,. 1968. . : . .'. -,,.;'; :;::r;.- . .;;; ;
A-62. Knipl-ing, E.B., S.H. West and W.T. Haller. Growth
Characteristics, Yield Potential, and Nutritive Content of Water
Hyacinths. Soil Crop Sci. Soc. Fla. Proc., 30:51-63, 1970.
A-63. Singh, J.S. and K.P. Singh. Contributions to the Ecology of Ten
Noxious Weeds. Ind. Bot. Soc. Jour., 46:440-451, 1967.
A-16
230
-------
A-64. Ueki , K., M. Ito and Y. Oki. Water Hyacinth and Its Habitats in
Japan. Proc. 5th Asian-Pac. Weed Sci. Soc. Conf., pp. 425-428,
1975.
A-65. Dale, H.M. and T. Gillespie. The Influence of Floating Vascular
Plants on the Diurnal Fluctuations of Temperature near the Water
Surface in Early Spring. Hydrobiologia, 49(3):245-256, 1976.
A-66. Godziemba-Czyz, J. Characteristic(s) of Vegetative and Resting
Forms in Wolffia arrhiza (L.) Wimm. II. Anatomy, Physical and
Physiological Properties. Acta Societatis Botanicorum Poloniae,
39(3):421-443, 1970.
A-67. Hicks, P.A. Interaction of Factors in the Growth of Lemna, V:
Some Preliminary Observations upon the Interaction of Temperature
.and Light on the Growth of Lemna. Ann. Bot., 48:515^525, 1934.
A-68. Hodgson, G.L. Effects of Temperature on the Growth and
Development of Lemna minor, under Conditions of Natural Daylight.
. Ann. Bot., 34:355^33l7"TW;0.. . ;
A-69. Porath, D. and Y. Ben-Shaul. Growth, Greening,.and Phytochrome
in Etiolated Spirodela (Lemnaceae). .Plant Physio!., .51:464-477,
. - 1973. -. . - - " -.> -...: ' -- ' . "
A-70. Porath, D. and Y. Ben-Shaul. Structural and Physiological
Changes during "Heat Bleaching" in Spirodela ol igorhiza. Israel
Jour. Bot., 20:157-168, 1971.
A-71. Stanley, R.A. and C.E. Madewell. Thermal Tolerance of Lemna
minor L. Circular Z-73, Tennessee Valley Authority, Mu.sc.le
Shoals, Ala., 16 pp., 1976.
A-72. Wilkinson, R.E. Effects of Light Intensity and Temperature on
the Growth of Waterstargrass, Coontail, and Duckweed. Weeds,
11(4):287-290, 1963. . ' .
A-73. Haller, W.T., D.L. Sutton and W.C. Barlqwe, Effects of Salinity
on Growth of Several Aquatic Macrophytes. Ecology, 55:891-894,
1974.
A-74. Strauss, R. The Effects of Different Alkali Salts on Growth and
Mineral Nutrition of Lemna minor L. Int. Revue Ges. Hydrobiol.,
61(5):673-676, 1976, TPrenctiTEnglish Abstract).
A-75. Stanley, R.A. and C.E. Madewell. Chemica.1 Tolerance of Lemna
minor L. Circular 2-72, Tennessee Valley Authority,
Muscle Shoals, Ala., Nov. 1976.
A-17
231
-------
A-76. Minshall, W.H. and G.W. Scarth. Effect of Growth in Acid Media
on the Morphology, Hydrogen-ion Concentration, Viscosity, and
Permeability of Water Hyacinth and Frogbit Root. Cells. Can.
Jour.-Got., 30:188-208, 1952.
A-77. Ultsch, G.R. The Effects of Water Hyacinths (Eichhornia
crassipes) on the Microenvironment of Aquatic Communities.
Archiv fur Hydrobiologie, 72(4):461-473, 1973.
A-78. Holmquist, C. Northerly Localities for Three Aquatic Plants,
Lemna trisulca L., Ceratophyllum demersum L., and Myriophyl 1 urn
spi.catum L. Bbt. Notiser., 124:335-342, 1971.
A-79. Lahdolt, E. Physiologische und okologische Untersuchungen an
Lemnaceen. Berichte der Schwei zeri sch^en Bptanischen
Gesellschaft, 67:271-410, 1957 (German/English summary)
A-80. Bock, J.H. Productivity of the Water Hyacinth Eichhornia
crassipes (Mart.) Solms. Ecology, 50(3):460-464, 1969.
A-81. Hiilman, W.S. and D.D. Culley, Jr. The Uses of Duckweed. Amer.
Sci., 66(4):442-451, 1978.
A-82. Sculthorpe, C.D. The Biology of Aquatic Vascular Plants. Edward
Arnold (Publishers) Ltd., London, 610pp., 1967.
A-83. Stodola, J. Encyclopedia of Water Plants. Crown Publishers, New
York, N.Y., 368 pp., 1967.
A-84. Anderson, R.E. Temperature and Rooted Aquatic Plants.
Chesapeake Sci.., 10(384):157-164, 1969,
A-85.' Haag, R.W. ; The Ecological Significance of Dormancy in Some
Rooted Aquatic Plants. Jour. Ecol., 67:727-738, 1979.
A-86. Menzie, C.A. Growth of the Aquatic Plant Myr.iophynum spicatum
in a Littoral Area of the Hudson Riv.er Estuary. A^uat. Bot.,
6:365-375, 1979. . : .
-------
A-90. Chapman, V.J., J.M.A. Brown, C.F. Hill and J.L. Carr. Biology of
Excessive Weed Growth in the Hydro-Electric Lakes of the Waikato
River, New Zealand. Hydrobiologia, 44(4):349-363, 1974.
A-91. Ozimek, T., A. Prejs and K. Prejs. Biomass and Distribution of
Underground Parts of Potamogeton perfoliatus L. and P. Lucens L.
in Mikolajskie. Aquat. Bot., 2:309-316, 1976.
A-92. Verhoeven, J.T.A. and W. vanVierssen. Distribution and Structure
of Communities Dominated by Ruppia, Zostera and Potamogeton
Species in the Inland Waters of ' De Bo 1', Texel, The Netherlands.
Estuar. Coastal Mar. Sci., 6:417-428, 1978.
A-93. Verhoeven, J.T.A. and W. vanVierssen. Structure of Macrophyte
Dominated Communities in Two Brackish Lagoons on the Island of
Corsica, France. Aquat. Bot., 5:77-86, 1978.
A-94. .Philip, C..C. and R.6. Brown. Ecological Studies of
Tratisi tio n-Zone Vascul ar Plants in South River, Maryland.
Chesapeake Sci., 6(2):73-81, 1965. .
A-95. Anderson, R.R., R.G. Brown and R.D. Rappleye. The M.ineral
Content of MyriaphyTlum spicatum,L. in Relation.to Its Aquatic
Environment.... Ecology, 47:844-.846, 1966. .
A-96. Davis, G.J., M.N. Jones, C.Z. Lunney and G.M. Clark. Inhibition
of Sodium Chloride Toxicity in Seedings of Myriqphyllum spicatum
L. with Calcium. Plant Cell Physiol., 15:577-581, 1974.
A-97 Haller, W.T., D.L.. Sutton and W.C. Barlowe. Effects of Salinity
on Growth of Several Aquatic Macrophytes. Ecology, 55:891-894,
1974. .
A-98. Stanley, R.A. Toxjcity of Heavy Metals and Salts to Eurasian
Watermilfoil (Myriophyllum spicatum L.). Arch. Environ. Contam.
Toxic., 2(4):331-341, 1974.
A-99. Denny, P. and D.C. Weeks. Effects of Light and Bicarbonate on
Membrane Potential in Potamogeton schweinfurthi i (Benn). Ann.
Bot., 34:483-496, 1970. ~~
A-100. Crowder, A.A.., J.'M. Bristow and M.R. King. Aquatic Macrophytes
of Some Lakes i.n Southeastern Ontario. Naturalists Can.,
104:457-464, 1977. .
.A-101. Hutchinson, G.E.. The Chemical Ecology of Three Species of
"m (An<
1-970.'
Myrioph.yJ_lum (Angiospermae, Haloragaceae). Limnol. Oceanog.,
15 r
A-19
233"
-------
A-102. litav, M. and Y. lehrer. The Effects of Ammonium-in Water on
Potamogeton lucens. Aquat.- Bot., 5:127-138, 1978.
A'-103. Kistritz, R.U, Recycling of Nutrients in an Enclosed Aquatic
Community of Decomposing Macrophytes ('Myriophyl 1 urn spicatum).
Ottos., 30:561-569, 1978.
A-104. Adams, M.S., P. Guilizzoni and S. Adams. Relationship of
Dissolved Inorganic Carbon to Macrophyte Photosynthesis in Some
Italian Lakes. Limnol. Oceanogr., 23(5):912-919, 1978.
A-105. Cole-, B.S. and D.W. Toetz. Utilization of Sed:imentary Ammonia by
Potamogeton nodqsus and Scirpus. Verh. Internat. Verein Limnol.,
19:2765-2772, 1975.
A-106. McNabb, C.D., Jr. The Potential of Submersed Vascular,,Plants for
Reclamation ovf Waste-water in Temperate Zone Ponds.; I n:
... Bio.Ta.g.ica-1 Control of Water PdTliition.,.. J* Tourbier and R.W.
Pierson., Jrv (eds) ,.. (pg. 123-132) Un-ivefsfty of P-en-nsyl van i a
Press, Philadelphia, Pa., 1976.,
A-10.7. Abdelmalfk, W.E..Y., R.M.K. El -Shinawy,. W..M. Ishak and K.A.
Mahmo-ud. Uptake of Radionuclides by Some Aquatic Macrophytes of
Ismailia Canal, Egypt. Hydrobtologia, 42(1):3-12, 1973.
A-108. Mudroch, A. and J.A. Capobianco. Effects-of Mine Effluent on
Uptake of Co, Ni , Cu , As, Zn , Cd , Cr and Pb by Aquatic
Macrophytes. Hydrobiologia, 64(3):223-231,. 19.79.
A-109. Anderson,. M.G. Distribution and Production of Sago Pondweed
(Potamogeton pectinatus L.) on a North-ern Prair.ie .Marsh.
Ecology-,. 59-(.l): 154-160, 1978.
A--110. GrT-ffiths,, 0; The Structure'of an Acid- Maori and Pond Community.
Jo-ur. Animal: Ecol., 42:263-283, 1973. ... . .. .
A1-!!!. -Holmquist, C., Northerly Local ities. for Three Aquatic Plants Lemna
trisuVca L. > Ceratophyllum demersum L. and MyriophyiVum .spieatum
L. .Bot. Notvser., 124:335-342, 1971.
A-11.2. Spence, O..H.N., T.R. Mtlburnj M. Ndawula-senytmba and E. Roberts.
Fruit Biology, and Germination of Two Tropical Pot a mo geton
Species. New- Phytol,., 70:197-212, 1971. '
A-113. Crowder, A.A., J.M. Bristow and M.R. King. Distribution,
Seasonality, and Biomass of Aquatic Macrophytes in Lake Opinicon,
(Eastern Ontario). Naturaliste Can., 104:441-456, 1977.
A-114. Kollman, A.L. and M.K. Wali. Intraseasonal Variations in
Environmental and Productivity Relations of Potamogeton
pectinatus Communities. Arch. Hydrobiol., Suppl., 50(4):439-472,
"
A-20
234
-------
A-115. Goulder, R. Interactions between the Rates of Production of a
Freshwater Macrophyte and Phytopl ankton in a Pond. Oikos,
20:300-309, 1969.
A-116. Hannan, H.H. and T.C. Dorris. Succession of a Macrophyte
Community in a Constant Temperature River. Limnol. Oceanog.,
15(1) = 442-453, 1970.
A-117. Ho, Y.B. Inorganic Mineral Nutrient Studies on Potamogeton
pectinatus L. and Entermorpha prolifera in Forfar Loch, Scotland.
Hydrobiologia, 62(1):7-15, 197?;
A-118. Anderson, R.R., B.G. Russell and R.D. Rappleye. Mineral
Composition of Eurasian Watermill foil , Myriophyl 1 urn spicatum L.
Chesapeake Sci., 6(1):68-72, 1965.
A-119. HotchMss, N. Common Marsh, Underwater and Floating-Leaved Plants
of the United States and Canada. 2 vols. 1967, 1970. Reprint (2
vols. in 1).. Dover Publications,. .New York, N. Y., 223 pp., 1972.
Ar21
235
-------
ro co
to r
cn
Figure B~1,
GEWRM.IZE6 INDCX OF tXI^TINQ A^O
ONGOING WtfLANfa INVENIORY DAT*
EXISTING STAIB AND LOCAL WETLANDS SURVEYS
UNITED STATES DEPARTMENT OF THE INTERIOR
Fi.sh and Wildlife Service
Office of DhiloKical Servicct
n
X
00
-------
ALABAMA
Vittor, B.A. and J.P. Stout. 1975. Delineation of ecological
critical areas in the Alabama coastal zone (75-002). Dauphin
Island Sea Lab. 32 pp.
ALASKA
Joint Federal-State Land Use Planning Commission for Alaska. 1975.
Resources of Alaska, a regional summary. Anchorage. 619 pp.
ARIZONA
Brown, D.E. and C..H. Lowe. 1974. A digitized computer compatible
classification for natura;! and potential vegetation in the
southwest with particular reference to Arizona. .Arizona.Academy of
Science. : Tucson. Vol. 9,'suppl. :N3.:2. ' '"'
Turner', D^M.:. and .Cii/Cbl-Tifig/^-dr. 1.975V;^:'lM'ldTife management' unit
37-B pilot planning study (job 1, FW-ll-R-.8); .Arizona Game and
Fish Commission. PhO'enix.. 1-28 pp. .- '<, .
ARKANSAS
Arkansas Department of State Planning. 1974. Arkansas natural
areas plan. Little Rock. 248 pp.
CALIFORNIA
California Coastal Zone Conservation Commission. 1975. California
coastal plan. Sacramento. . 443 pp.
State of California, Department of Fish and Game. 1975. The
natural resources of Lake Earl and the Smith.River Delta.
Sacramento. 114 pp. . .
1975. The natural resources of Bodega Harbor.
Sacramento. 183 pp.
' 1974, The natural resources of Los Penasquitos
Lagoon, and reco"[im6nclatiofls for use-and development. Sacramento.
75 pp. -
_^ . 1973. The natural resources of San. Diego Bay;
their status and future. Sacramento. 105 pp*
' 1974. The natural resources of Nbrro Bay; their
status and future. Sacramento. 103 pp.
B-2
237
-------
1970. The natural resources of Bolinas Lagoon; their
status and "future. Sacramento. 107 pp.
1974. The natural resources of th.e .Eel .River Delta.
'Sacramento. 108 pp. . .: . . ;
__^ .. . 1973. The natural resource's of ,'Hu-mb.oldt Bay.
Sacramento. 160 pp.
COLORADO ... ..'...-
Hooper, R.M. 1968. Wetlands of Colorado. Tech. .Publ, No. 22.
Colorado Game, Fish and Parks Department. Fort Collins. 88 pp.
CONNECTICUT '{. :
USDI, Fish and .Wildlife Service. 1965. Supplemental report o.n the
coastal wetlands inventory of Connecticut. Boston, llpp.
DELAWARE - ','' .
Delaware State Planning Office. 1970. Delaware natural resources
inventory. Dover. Partial copy.
Delaware State Planning Office, State Department of Environmental
Control, and USDA. 1969. Environmental study of Rehobtith, Indian
River and Assawoman Bays. Dover. Partial copy.
Klemas, V., 'F.C. Daiber, D.S. Baptl-ett, O..W. 'Chrichton -and A.O.
Fornes. 1973. Coastal vegetation of Delaware, the mapping of
Delaware's "coastal marshes. Untversity of Delaware, J?o 11 ege of
Marine Studies.; Dover, 29 pp. v ;; :,,:;".: - '; "
KTemas, V. and D. Bartlett. 1975. Delaware-wetVands inventory
final report. -University o'f Delaware, ColTege of Marine 'Studies.
Dover* Partial copy.
USOI, Fish and Wildlife Service. 1965. Suppl-emen'tal report on the
coastal wetl-a'nds inventory of Delaware. Boston, MA. 13 pp.
Walton, T.E., III. and R. Patrick-, eds. .1973. Delaware River
estua'rine marsh survey. 'The Acadamy''of .Natural Sci-ences.
Philadelphia, PA. 172 pp.
FLORIDA
State of Florida, Coastal Coordinating Council. 1972. Florida
coastal zone management atlas. Tallahassee. Partial copy.
'B-3
238
-------
GEORGIA
Georgia Department of Natural Resources. 1975. User's information
for coastal resources maps. Office of Planning and Research.
Atlanta. 39 pp.
HAWAII
Gagne, W. Unpubl. Synopsis of terrestrial ecosystems. State of
Hawaii. Honolulu. Xerox.
IDAHO
No survey . .... ;
ILLINOIS
No survey
INDIANA '
State of Indiana, Department of Natural Resources. 1964. Wetlands
of northern Indiana. Division of Fish and Game. Indianapolis. 14
pp. . ...-.,-
IOWA
No survey
KANSAS
No survey
KENTUCKY . . .
No survey , . ' ..-.
LOUISIANA '"' -' . ""
Chabreck, .R.-.H., T. Joenen and A.W. Palmisano. 1968.. Vegetative
type map of the Louisiana coastal marshes. Louisiana Wildlife and
Fisheries Commission. New Orleans.
___^_^ . 1972. Vegetation, water and soil characteristics
of the Louisiana Coastal Region. Louisiana Agricultural Experiment
Station Bulletin. 664. 72pp.
Perrett, W.S. et al. 1971. Cooperative Gulf of Mexico estuarine
inventory and study, Louisiana phase I, area description.
Louisiana Wildlife and Fisheries Commission. New Orleans.spp.
9-11.
B-4
239
-------
USD;I, 1975. A progress report, fish, wildlife, and related
resources Atchafalaya River Basin, Louisiana.. U.S. Government
Printing Office. Washington, DC. 154 pp. .
MAINE
Maine Department of Inland Fisheries and Game. 1972; Manual for
Maine wetlands inventory. Augusta. 37pp.
Maine State Planning Office. 1974. Standard classification system
for land cover in Maine. Augusta. 26 pp.
. 1975. Standard classification system for land
use coding in Maine. Augusta. 47 pp.
USDI, Fish and Wildlife Service. 1965. Supplemental report on the
coastal wetlands inventory of Maine. Boston, MA. 11 pp.
U.S. Army Crops of Engineers. 1972. Water resources development
plan, Charles River watershed. Waltham, MA. 113 pp.
MARYLAND
Lippson, J., ed. 1973. The Chesapeake Bay atlas; an atlas of
natural resources. University of Maryland.. 55 pp.
Metzger, R.G. 1973. Wetlands in Maryland. Maryland Department of
State Planning. Annapolis.
Rodgers, J., S. Syz and F. Golden. 1975. Maryland uplands natural.
areas study -Vp-V. I. Maryland Department of Natural Resources,
Coastal Zone Management Program. Annapolis. 83 pp.
MASSACHUSETTS ,.,-.....' ', ;^, ^,f.:..-, . -:
;,:, . Universityo.f Massachusetts, Cooperative Extension Service. 1973.
Land-use and vegetative cover mapping, classifications manual for
_...', .use- with Massachusetts map down-maps. .Publ. 97:' Amherst.- 1-8 pp-.
. . USDI, .Fish and Wildlife Service. 1965. Supplemental report on. the
coastal wetlands inventory of Massachusetts. Bo:ston, MA. .13 pp.
M-ICHIGAN
Tanner, H.A., Director. 1976. Michigan land cover/use
classification system. Michigan Land Use Classification and
Referencing Committee. Office of Land Use..- Department of Natural
Resources. Lansing. 60 pp.
MINNESOTA
No survey
6-5
240
-------
MISSISSIPPI
Eleuterius, L.N. 1968. The marshes of Mississippi. In:
Cooperative Gulf of Mexico estuarine inventory and study (1973).
Gulf Coast Research Laboratory. Ocean Spring, MS. pp. 147-190.
MISSOURI
Elder, W.H. and D. Muser. 1974. A natural area survey of the
Kaysinger Basin. Final Report to Missouri State Inter-Agency
Council for Outdoor Recreation. Partial copy.
MONTANA
No survey
NEBRASKA . . ' ,
Nebraska Game and Park Commission. 1972. Survey of habitat -work
plan K-71. Lincoln. 78 pp.
Missouri River "Basin Commission. 1975. Platte River
Basin-Nebraska. Fish and Wi1dlife Technical Paper. U.S.
Government Printing 'Office. Washington, DC. 120 pp.
NEVADA . .. -
Osugi, C.T, 1973. Report of wildlife management study. Stillwater
Wildlife Management Area. Fallon, 'NV. 45 pp.
;. Ibid. 1974. 49 pp.
NEW HAMPSHIRE
Breeding, C. H.J., F. Richardson and S. Pilgrim. 1974. Soil
survey of New Hampshire tidal marshes, RR. to. 40. New Hampshire
Agricultural Experiment Station, in Cooperation with USDA, SCS.
Durham. 94 pp. .and map supplement.
Carter, J.F. 1968. .Wetlands report. New Hampshire Water Resources
Board. Concord. Mimeo.
Inland Wetland Study Commission. 1971. The inland wetlands of New
Hampshire. Concord. 28 pp.
State of New Hampshire. 1966. New Hampshire long range planning
study. Concord. Partial copy.
B-6
241
-------
Tidal Wetland Study Commission. 1971. Report to the New Hampshire
legislature. Concord. 18 pp. . . . .
USDI, Fish and Wildlife Service. 1965. Supplemental report on the
coastal wetlands inventory of New. Hampshire. Boston, MA. 11 pp.
NEW JERSEY
USDI, Fish and Wildlife Service. 1965. Supplemental report on the
coastal wetlands inventory of New Jersey. Boston, MA. 13 pp.
NEW MEXICO
State of New Mexico. 1972. Reservoirs and lakes under forty
surface acres in New Mexico. State Engineering Office. Sante Fe.
12 pp.
... 1972. Reservoirs and lakes in New Mexico with
forty or mo-re surface acres. State Engineering Office. Santa -Fe.
12 pp. .
NEW YORK
No survey
NORTH CAROLINA .
Wilson,. K.A.. 1962. North Carolina, wetlands, their distribution and
management. North Carolina Wildl-ife Resources Commission. Raleigh.
169 pp.
NORTH DAKOTA j/w^: '.. '" V. ''.. "..:;. '".'/ ':'
No survey '' - . ,; '.......'..-. ',....' ''''- ..=. . ..<-;"
OHIO = '''- '": -; '. .: ' , / ......',. ,:-
State of Ohio. 1974. Ohio wetlands i.nv.e.nto.ry. Final report.
Division of WiWVife. Project No. W-104.-R-16. Columbus. 51 pp.
OKLAHOMA . . .
USDA, Soil Conservation Service. 1974. Oklahoma soil conservation
service land use definition system. Stillwa-ter.
B-7
242
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OREGON
Oregon Coastal Conservation and Development Commission. 1974.
Visual resource analysis of the Oregon coastal zone, experimental
qualities of Oregon coastal environments. Walker, Havens and
Erickson. Eugene. 135 pp.
State of Oregon, Division of State Lands. 1973. Oregon estuaries.
Salem. 50 pp.
State of Oregon, Executive Department and Natural Resources
Agencies. 1973. An inventory and evaluation of areas of
environmental concern in Oregon. Battelle Laboratory. Richland,
,WA. 104 pp.
State of Oregon, Land Conservation and Development Commission.
1975. Statewide planning goals and guidelines. Salem. 8 pp.
U.S. Army Corps of Engineers. 1975. Final environmental, .impact
statement,'Columbia and Lower Wi 11 amette River maintenance and
completion of the 40-foot navigation channel downstream of
Vancouver, Washington: and Po-rtland, Oregon. Portland. 166 pp. and
appendices. ...
____ 1975. Draft environmental impact statement,
Corps of Engineers activities in the Chetco, Coquille and Rogue
River Estuaries and Port Orford, Oregon. Portland. Various pp.
__. 1975. Volume II, technical appendices A-Z, to
draft environmental impact statement, Corps of Engineers activities
in the Chetco, Coquille, and Rogue River Estuaries and Port Orford,
Oregon. Portland. Various pp.
-. . ,1975. Draft environmental impact statement
operation and maintenance ofthe channels and breakwaters in
Yaquina Bay and River, Oregon, fbrt1,an
-------
OREGON
1975. Resource analysis of Oregon's coastal
uplands. Eugene. 204 pp.
:.. '". ,. . 1973. Coastal wetlands of Oregon. Florence. 159
'PP. '. . . '' ; . .:"' ' ,"'
... . and US DA, Soil Go nservation Service. 1975. Beaches
and dunes of the Oregon coast. Portland. 161 pp.
.. 1975. Draft environmental impact statement, the
Suislaw Estuary and Umpqua Estuary, including the Smith River.
Portland. Various pp.
. 1975. Draft supplement, environmental impact
statement, Coos Bay, Oregon deep draft navigation environmental
impact statement. Portland; Various pp.
.,' ,./... :.., . .-.'. 1975. Draft Supplement environmental impact
statement> background information to the Coos Bay deep draft
navigation project. Vol. II. /Portland, various pp.
. . ..,'... . 1975. Preliminary draft: Wetlands review of
Siletz Bay, Oregon. Seattle, WA. 81 pp.
.... 1974. Draft environmental impact .statement,
operation and maintenance of jetties and dredging projects in
Tillamook Estuary, Oregon. Portland. .......
PENNSYLVANIA
No survey . ',-
;RHODE ISLAND --; . ,' ; ;..;'.;.; ., .'./,,.. ,
Kupa, J. J. :and W.R* Whitman. 1972. Land cover types o.f Rhode
Island. Agricultural Experiment Station, Bulletin No. 409.
Kingston. "30pp.
Rhode-Isla-nd Department of Administration. T975. Annual report of
the'.'Rhode Island statewide: planning program for fiscal year
1974-1975 and proj'ect completion report. Providence. 115 pp.
State of Rhode Island. 1971. Coastal resources management council
plan, policies and regulations. Coastal Resource Management
Council. Providence. 76 pp.
B-9
244
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University of Rhode Island, Cooperative Extension Service. 1974.
Remote sensing of land use and vegetative cover in Rhode Island.
Bulletin No. 200. Kingston. 93 pp.
USDI, Fish and Wildlife Service, 1965. Supplemental report on the
coastal wetlands inventory of Rhode Island. Boston, MA. 10 pp.
SOUTH CAROLINA
Duncan, R.E. 1975.
productivity study.
Columbia. 28 pp.
SOUTH DAKOTA
Wando River aerial imagery and marsh
South Carolina Water Resources Commission.
Anderson, ,M.E. 1960. Project o.utl.ine for pilot .study "for wetlands
inventory. South Dakota Department of Game, Fish and Parks.
Pierre. Mimeo. ., . ......
Frederickson, L.F. 1970. Wetlands inventory-rKingsbury County,
South Dakota. South Dakota Department of Game, Fish and Parks, P-R
proj. ND.W-75-R-12. Pierre. 30pp.
.TENNESSEE .
Barston, C.J. 1970. Fish and Wildlife resources, Obion-Forked Deer
River Basin, Tennessee. Tennessee Game and Fish Commission.
Nashville. 36 pp.
USDA, Soil Conservation Service, Economic Research Service and
Forest Service. 1975. Second interim report, Obion-Forked Deer
River Basin Survey. Nashville, TN. 84' pp. 6 maps.
. 1973. Interim report, Obion-i-Forked Deer River
Basin survey. Nashville, TN. 34 pp.
TEXAS
Fisher., W.L., J.H. McGowen, L.F. Brown, Jr. and C.G. Groat. 1972.
Environmenta1 geo1ogic atlas of the Texas coastal
zone-Galveston-Houston area. Bureau of Economic Geology,
University of Texas. Austin. 94 pp. 9 maps.
UTAH
Jensen, F.C. 1974. Evaluation of existing wetland habitat in Utah,
State of Utah, Division of Wildlife Resources, Proj. No.
W117-L-D-R. Salt Lake City. 219 pp.
VERMONT
No survey
B-10
245
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VIRGINIA
Hobbs, C.H., II., G.L. Anderson, R.J. Brys,e and J.M. Ziegler. 1975.
Shoreline situation report, City of Hampton^ Virginia. Virginia
Institute of Marine Science. Gloucester Point. 37 pp. Map
supplement. .....
Johnson, R.F., L.J. Baer, J.C. Barlow, W.M. Grouse, F.R. Frisbie
and W.J. Comery. 1974. Mapping survey of the marine wetlands of
the Rudee and Lynhaven areas of Virginia Beach, Virginia.
Institute of Oceanography, Old Dominion University. Norfolk. 20
pp. Map supplement.
Marine Resources Commission. 1974. Wetland guidelines pursuant to
section 62.1-13.4 Code of Virginia. Newport News. 47pp.
Settle, F.-H. 1969. Survey-and analysis of changes effected by man
on tidal wetlands of Virginia, 1955-1969. Master's Thesis.
Virginia Polytechnic Institute. Blacksburg.
Silberhorn, G.M. 19.74. York County and Town of Poquoson tidal
marsh inventory. Special Report No. 53. In: .Applied Science and
Ocean Engineering. Virginia Institute of Marine Science.
Gloucester Point. 67 pp.
Silberhorn, G.M., G.M. Davis and T.A. Barnard, Jr. 1974. Coastal
wetlands of Vi rginia, interim report no. 3. In: Applied Marine
Science and Ocean Engineering.. No. 46. Virginia Institute of
Marine Science. Gloucester Point. 52 pp.
WASHINGTON
Northeast Environmenta;! Consultants. 1975.; The ti-dai'marshes of
Jefferson-County, Washington. Bainbrtdge Island; 94pp.
State of Washington, Department of Ecology. 1975.. Baseline study
program North Puget Soundvoil pollution' and the signi fvcant
biological resources of Puget Sound, annotated bibliography.
Olympia. 199 pp. '.= ' ' ' ';
. . 4" 1975. Baseline study program Nortti Puget- Sound,
an interim report to the 44th legislature, State of Washington.
Olympia. 35 ppi and attachments.
State of Washington, Department of Ecology, Department of Fisheries
and Department of Game. 1974. Study plan, Grays Harbor dredging
effects study: A report submitted to the U.S. .Army Corps of
Engineers, Seattle District. Olympia. 77 pp. and appendix.
B-ll
246
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Taber, R.D. and J.C. Garcia.
Wetlands and their value as
Washington. Seattle. 46 pp.
1975. Survey of Skagit County
wildlife habitat. University of
U.S. Army Corps of
impact statement ,
project-Washington.
Engineers. 1975. Revised draft environmental
Willapa River and harbor navigation
Seattle. 99 pp. and appendices.
B-12
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APPENDIX C
ANNOTATED BIBLIOGRAPHY
WETLAND PROCESSES AND CHARACTERISTICS
C- 1. Bartlett, M.S., L.C. Brown, N.B. Hanes and N.H. Nickerson.
Denitrification in Freshwater Wetland Soil. Jour. Environ. Qua!
5(4): 460-464, 1979.
This laboratory study demonstrated biological denitrification in
freshwater wetland soil and attempted to accurately measure
denitrification rates. At least 90 percent of supplemental
nitrates were reduced to gaseous nitrous oxide and nitrogen gas,
with little or no transfers of nitrate to ammonia or organic
nitrogen fractions. . , .
C- 2. Brinson., M.M.'Decomposition and Nutrient Exchange of Litter in an
Alluvial Swamp Forest. Ecology 58: 601-609, 1977.
Weight loss from cellulose sheets was measured monthly at three
sites of a North Carolina swamp forest to determine whether
nutrient demand by heterotrophs that decompose forest litter is
quantitatively important for the internal recycling and
accumulation of nutrients. Rates of loss were significantly
different seasonally, and between sites. Both temperature and
moisture appeared to be important in controlling decomposition
rates. Nutrients appeared to be tightly conserved and recycled,
even in swamps subject to flooding during tree dormancy.
C- 3. Engler, R.M., W.H. Patrick, Jr. Nitrate -Removal from Floodwater
Overlying Flooded Soils and Sediments. Jour. Environ. Qual.
3(4)409-413, 1974.
The floodwater nitrate removal rate of intermittently flooded
freshwater swamp soils and continuously flooded saline marsh
soils of southern Louisiana was quantitatively characterized in a
laboratory study. Of the two areas studied, the marsh area was
the more effective sink for nitrate contaminated waters-,-with an
average initial removal rate of 9.15 ppm N/day. The swamp soil
had a removal rate of 4.38 ppm N/day. Studies on samples of
floodwater separated from the soil showed the active sites of
microbial nitrate reduction to be the soil-water interface and
within the soil, but not in the floodwater. Additions of organic
matter to a mineral soil flooded for rice culture decreased the
thickness of the aerobic-anaerobic zone at the soil-water
interface and increased the rate of nitrate reduction.
C-l
248
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C- 4. Hall, F.R., R.J. Rutherford and G.L. Byers. The Influence of a
New England Wetland on Water Quantity and Quality. University of
New Hampshire, Durham, N.H., 1972.
Hydrologic, meteorologic and chemical data were collected from a
pond/wetland in southeastern New Hampshire to determine its
influence on water quantity and quality. Little evidence of
systematic or predictable trends was found, since the date showed
considerable scatter with time and geographical location.
However, the water chemistry showed some evidence of seasonal
trends, with total dissolved solids tending to increase from
spring into early fall.
C- 5. Isirmiab, N.O. and D.R. Keeney. Contribution of Developed and
Natural Marshland Soils to Surface and Subsurface Water Quality.
University.-of Wisconsin, Madison, Wis., 1973.
Preliminary qualitative estimates of the role of natural and
developed marshland soils as nitrogen or phosphorus source or
sinks were obtained by a,Limited ground and. surface water survey
of a marsh adjacent to Lake Wingra, near Madison, Wisconsin, and
by laborato ry 'investigations of nitrogen and phosphorus
transformations in soil samples from this marsh and from an acid
bog in northern Wisconsin. The results indicated that this marsh
does not act as a significant nutrient sink, and that though
removal of the marsh by draining or filling might result in more
nitrogen and phosphorus entering the lake, the presence of the
marsh does not appear to lower lake productivity.
C- 6. Lee, G.F., E. Bently and R. Amundson. Effects of Marshes on
Water Quality-. University of Wisconsin, Madison, Wis., 1969.
The effects of marshes on water quality and the leaching of
aquatic plant nutrients from drained marshes were studied at four
marsh areas located hear Madison, Wisconsin. Marshes were shown
to;have both- beneficial and detrimental effects on water quality.
the drainage of a marsh for agriculture-urban purposes was found
to cause a significant release of aquatic-plant nutrients, which
accelerated the eutrophication of receiving waters.
C- 7. Nicholls, K.H. and H.R. MacCrimmon. Nutrients in Subsurface and
Runoff Waters of the Holland Marsh, Ontario. Jour. Environ.
Qua!. 3(l):31-35, 1974.
The relative surface runoff contributions of nutrients and total
electrolytes from cultivated and uncultivated plots of muck soil
within the Holland Marsh were studied. Changes in water
chemistry and the extent of leaching of nitrogen and phosphorus
during the growing season were also recorded. The duration and
amount of rainfall, which determined the extent of runoff or
C-2
249
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percolation into the soil, were shown to be important in
determining nitrate and to a lesser :extent, soluble reactive
phosphorus concentrations in water under the'-cultivated-plot, but
not beneath the uncultivated plot.
C- 8. Shih, S.F., A.C. Federico, J»F. Milleson and. M* Rosen. Sampling
Programs for Evaluating Upland Marsh to Improve Water Quality.
Trans. ASAE, pp. 828-833, 1979.
Performance of upland marsh to improve water quality was
evaluated using an indirect sampling program which included water
chemistry, marsh vegetation, nutrient uptake, soil profile
nutrient content, and flow velocity measurement at the Chandler
Slough Basin of the Kissimmee River, Florida. The first flush of
the wet season, which washes out some of the decaying organic
matter, was found to be an important factor affecting nutrient
retention in the marsh. The marsh can act as a phosphorus sink
if the first flush effect can be controlled by either a retention
pond, which reduces the peak flushing flows,or, by harvesting the
marsh vegetation. Soil sampling showed that the highest
nitrogen, phosphorus, and calcium concentration were in the
surface layer of soil. . .
C- 9. Verry, E.S. Streamflow Chemistry and Nutrient Yields from
Upland-Peat!and Watersheds in Minnesota. Ecology 56:1149-1157;
1975. , ... , : .."; --- .
Twenty-two water quality parameters were determined over a period
of five years for the streamflow from five watersheds with
oligotrophic peatlands and one with a minerotrophic peatland.
Concentrations of organically derived nutrients were highest in
the streamflow from watersheds containing oligotrophic peatlands,
while concentrations of nutrients derived from solution of
aquifer minerals were higher in streamflow from the watershed
containing a- minerotrophic peatland. However, flow-weighted
concentrations of organically derived nutrients were similar for
both-watersheds. ...
WETLANDS UTILIZATION FOR WASTEWATER AND ,-STORMWATER TREATMENT
C-10. Blumer, K. The Use of Wetlands for Treating- Wastes --» Wisdom in
Diversity? _I_n_: Environmental Quality Through Wetlands
Utilization. Proceedings from a Symposium Sponsored by the
Coordinating Council on the Restoration of the Kissimmee River
Valley and Taylor Creek-Nubbin Slough Basin, February 28-March 2,
1978. Tallahassee, Fla ., 1978.
A management policy is needed for the Kissimmee Watershed,
Florida to alleviate water quality problems caused by high
seasonal nutrient flushes. Research at the Brookhaven National
C-3
250
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Laboratory indicates that the utilization of a marsh ecosystem to
treat municipal effluent is not as efficient as is a meadow
ecosystem in combination with the marsh. Their comparative
Studies of a meadow/marsh/pond system and a marsh/pond system
have shown greater improvements in water quality in the more
diverse, meadows/marsh/pond artificial wetland system. It is
recommended that this principle be applied to an artificial
wetland system for treatment of agricultural runoff in the
Kissimmee Watershed.
C-ll. Boyt, F.L., S.E. Bayley and J. Zoltek, Jr. Removal of Nutrients
from Treated Municipal Wastewater by Wetland Vegetation. Jour.
Water Poll. Control Fed. 49(5):789-799, 1977.
The ability of a mixed hardwood swamp to remove nutrients from
treated municipal wastewater was studied. A nutrient budget for
phosphorus was developed for analysi s o f the system. A
comparison was made between the costs of adding tertiary
treatment capabilities to the municipal wastewater.,facilities and
the cost of using natural wetland vegetation for treatment.
C-12. Cederqui st , H. Wastewater Reclamation and Reuse Pilot
Demonstration Pro-gram fo.r the Suisun Marsh. U.S. Department of
the Interior, Bureau of Reclamation, Sacramento , Gal ifornia ,
1977. .. .;-... . : ; '
The compatibility of treatment and reuse of municipal and
industrial wastewater, and marsh management was evaluated in
there phases: high-rate irrigation of pasture to test the use of
a living filter to remove nitrogen and phosphorus from
wastewater; the use of symbiotic algae ponds for nitrogen removal
and for storage of water for flooding the grass marsh ponds; and
the cultivation of alkali bulrush and watergrass for waterfowl
food. ' . .
.C-13. .Demgen.,. F.C. and J.W. Mute, Wetlands .Creation Using Secondary
Treated Wastewater; Proceedings from a Water Reuse Symposium,
Vol. I, March 25-3.0, 1979. Washington O.C., 1979. .
The use of treated municipal wastewater to create a wetlands
- environment for the benefit of wildlife and migratory waterfowl
is described, together with a reuse method that combined
wastewater and wildlife management for optimum results.
C-14. Dinges, R. Upgrading Stabilization Pond Effluent by Water
Hyacinth Culture. Texas Department of Health, Austin, Tx., 1978.
An experimental culture of water hyacinth was used to treat
stabilization pond effluent. As a result of the efficient
removal of suspended solids and dissolved impurities, water
C-4
251
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qua!ity improvements were substantial. Effluent from the system
was low in .nitrogen, low in fecal coliforrirbacteria and showed
large; reductions in BOD, total suspended .so 1 ids and COD.
Minerals accumulated in plant material from basin waters were
chloride., potassium, phosphorus, arsenic, chromium, mercury,
iron', lead, nickel, zinc, copper, magnesium and manganese.
C-15. Dinges, R. Water Hyacinth Culture for Wastewater Treatment.
Texas Department of Health Resources, Austin, Tx., 1976.
The capability of water hyacinth to improve the quality of sewage
effluent wasvdemonstrated. Literature pertaining to the uptake
of nutrients and other minerals by water-hyacinth was surveyed.
Projects utilizing water hyacinth to treat sewage effluents were
reviewed. j
C-16. Dinges, W.R. Who Says Treatment Plants Have to be Ugly. Water
and Wastes Engr., April, 1976.
The results.of a pilot project at the Williamson.Creek Wastewater
Treatment Plant in Austin, Texas, showed that water hyacinth
appears to.have the ability to accumulate heavy metals and trace
organics.. Similar projects indicating the efficiency of water
qua!ity improvement by water hyacinth, located in Bay St. Louis,
Mississippi; Orange Grove, Mississippi; Washington, D.C; and in
various locations of Florida, Louisiana and Colorado, were also
reviewed.
C-17. Fetter, C.W., Jr., W.E. Sloey and F.L. Spangler. Use of a Natural
Marsh for Wastewater Polishing. Jour. Water Poll. Control Fed.
50 (2): 290-307:, 1978 V...1 ;.
A stream, flowing through Brill ion Marsh, Wisconsin, was sampled
for water-quality at three stations: one located near the point
.of discharge of sewage: effluent, one upstream of the Discharge
for "marsh background" values, and one downstream, of the
di scharge.-po.i nt 'for the determination of water., qua! ity
improvement. The results indicated significa-nt improvements in
water quality parameters.
C-18. Grant, R.R. and' R. Patrick. Tinicum Marsh ,as a.Water Purifier.
Acad. Nat. Sci., Hearings of a Co mm.''on Merchant' Marine
Fisheries, pp. .173-191,. November 5, 1971,
The Tinicum Marsh, located near Philadelphia, Pa., receives
sewage effluent from three municipal treatment plants. A survey
of the flora and? fauna of the area indicated'that the environment
has been substantially degraded by the introduction of large
quantities of organic wastes. Results of preliminary
investigations, however, demonstrated that the marsh, even in its
C-5
252
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altered condition, can contribute to substantial reductions in
BOD, phosphates, nitrates and ammonia and increase the oxygen
content of the water.
C-19. Hartland-Rowe, R.C.B. and P.B. Wright. Swamplands for Sewage
Effluents, Final Report. Information Canada, Task Force on
Northern Oil Development, Report No. 74-4, 1974.
The effects on the local natural swampland ecosystem of released
municipal sewage effluent from the town of Hay River, N.W.T. ,
were examined. Water chemistry, bacteria levels, community
structure and diversity, nutrient levels in soil and root
materials, standing crop and primary production were studied.
C-20. Hickok, E.A., M.C. Hannaman and N.C Wenck. Urban Runoff
Treatment Methods, Volume I.- Nonstructural .Wetland Treatment.
EPA-600/2-77-217, Cincinnati, Ohio, December 1977.
A study of the water quality of the Lake Minnetonka Watershed
" demonstrated the effectiveness of treatment,of urban runoff-by
natural wetlands. The wetland retained 77 percent of all
phosphorus and 94 percent of total suspended sol ids entering the
site as a result of various -.physical , biologi.c.a.1 and chemical
mechanisms. . '"."" ' ,: ; " ;" ., ''..'.'':'
C-21. Hickok, E.A., E.J. Johnson, N.C. Wenck and M.A. Zagar... Urban
Runoff Treatment Methods, Volume II - High-Rate Pressure
Filtration. EPA Grant No. S-802535, Cincinnati, Ohio, December
1977. '
Stormwater runoff, a no n point"'source of water pollution,
substantially contributes to the degradation in quality of the
surface waters. High-rate filtration, using three pressure
filters, was evaluated as a means of improving the quality of
Stormwater runoff. In addition, a pilot test was conducted using
organic soil filters. .''...
C-22. Houghton Lake Sewer Authority. Concept, Research, Approval: An
Effluent Irrigation Project. Consult. Engr. 48(5):77, 1977.
A test program for a marshland irrigation system for the disposal
of treatment plant effluents was developed. Financial and
environmental considerations were evaluated.
C-23. Kadlec., R>N. :and D.L. Tilton. -Waste-water Treatment .via Wetland
Irrigation: Nutrient Dynamics. In: Environmental Quality through
Wetlands Utilization, Proceedings from a Symposium Sponsored by
the Coordinating Council on the Restoration of the Kissimmee
River Valley and Taylor Creek-Nubbin Slough Basin, February
28-March 2,.1978. Tallahassee, Fla., 1978.
.C-6
253
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Phosphorus and nitrogen were shown to be removed from secondary
effluent discharged into the Bellaire .wetland treatment system.
Average removals of 80 percent to 90 percent' fo r both were
indicated. Monthly variabil ity of -removal, were attributable to
'. patterns of hydrological condition, plant growth and temperature.
Decreases in the percentage, removal may be caused by low
temperatures, low residence times or small effective surface
areas.
C-24. Kadlec, R.H., D.L. Tilton and J.A. Kadlec. Nutrient Removal from
Secondary Wastewater in a Central Michigan Peatland (Houghton
Lake, Michigan). University of Michigan, 1977.
Wetland tertiary treatment of sewage effluent is planned for a
peatland at Houghton Lake, Michigan. The background ecology,
water chemistry and hydrology of the wetland have been
established. Test plots indicated the ability of the wetland to
remove nutrients from the sewage. Continued research and
monitoring is anticipated fol lowing the .establ is.hfnent of the
full-scale operation.
C-25. Morris, F.A. * M.K, Morris, T.S. Michaud and L.R. Wi 11 i ams.
Meadowland Natural Treatment Processes in the Lake Tahoe Basin :
A Field Investigation. U.S. EPA, Environmental Monitoring
Systems Laboratory, Las Vegas, Nev., 1980.
The effectiveness of natural meadowlands and wetlands in trapping
nutrients and sediments from surface runoff was investigated. In
systems where the water remained channelized, phosphorus,
nitrogen, suspended solids and organic carbon concentrations
usually remained unchanged or increased. In systems, where the
water spread out as sheet flow, total phosphorus; nitrogen ,
turbidity, TOC, and residue were reduced. The nutrient removal
effectiveness of the wetlands approached that of conventional
tertiary treatment. ': ' ;; ; ".'..,
C-26. Mudroch, A. and L.A. Capobianco. Effects of Treated Effluent on
a Natural Marsh. Jour. Water Poll. Control Fed. 51 (9):2243-2257,
1979. .,., . ;
. The effect of a constant supply of effluent from a municipal
wastewater treatment facility on the plant communities in a
natural marsh area, and the availability and cycling of nutrients
and heavy metals in the marsh were studied. Increased quantities
of heavy metals were found in sediment samples, but nutrient
levels were consistent with those of unpolluted marsh sediments.
Plant s.pecies growing in the marsh showed varying levels of
increase in concentrations of heavy metals and nutrients. '
C-7
254
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C-27. Ornes, W.H. and K.K. Steward. Effect of Phosphorus and Potassium
on Phytoplankton Populations in Field Enclosures. Agricultural
Research Service, Fort Lauderdale, Fla., 1973.
Experimental and controlled field enclosures in a marsh
environment were treated with weekly applications of phosphorus
and potassium. Results indicated a significantly disrupted
environment.
C-28. Pirrung, D.E. Feasibility of Utilization of a Wetland for
Nutrient Removal from Secondary Municipal Wastewater Treatment
Plant Effluent. Proceedings of the 2nd Annual American Water
Resources Conference - Wisconsin Chapter, 1977.
The City of Waupan, Wisconsin, was required to upgrade and expand
wastewater treatment facilities as a result of strict effluent
Limits imposed by the Wisconsin Department of Natural Resources.
Among the various alternatives considered was the treatment of
secondary effluent by an adjacent wetland. The natural treatment
.method was shown to be cost-effective for certain levels of
. . ''..'. treatment. . . . .
C-29. Roche*. W..M. Wastewater Reclamation and Reuse in the Suisun Marsh,.
California. National Conference on Environmental Engineering
Research., Development and Design. University of. Washington ,
Seattle, Wa., 1976.
The Suisun Marsh program was reviewed and application of the
results were discussed.
C-30. Small, M.M. Meadow/Marsh Systems as Sewage Treatment Plants.
Bropkhaven National Laboratory, Upton, N.Y. 1975.
Two natural, closed systems for sewage treatment, a
- meadow/mars.h/pond and a marsh/pond system, were compared. Land
requirements, and cost comparisons were made. .... :-.-.
C-31. University of Michigan, School of Natural Resources and the
College of Engineering. Freshwater Wetlands and Sewage Effluent
Disposal. Proceedings of a Symposium, May 10>11, 1976,
University of Michigan, Ann Arbor;, Mi., 1976.
The findings of research from projects pertaining to the
utilization of freshwater wetlands for the treatment of secondary
effluent at study sites located in Michigan, Wisconsin, New
Jersey, Louisiana, Florida, New York and Minnesota were
collected. The studies emphasized the hydrology and nutrient
balances of the wetlands.
C-32. Small, M.M. Data Report, Marsh/Pond System. Brookhaven National
Laboratory, Upton, N.Y., 1976.
C-8
255
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The design and operation of a marsh/pond sewage treatment system
were described. Observations and data collected from the system
during the year were also provided, but no conclusions were
drawn.....-.-'"' .
C-33. Small, M.M. Marsh/Pond Sewage Treatment Plants. Brookhaven
National Laboratory, Upton, N.Y., 1976.
A natural wastewater purification system was investigated for
cost effectiveness and its capacity for treatment. The size of
the marsh required to treat the wastewater for various population
sizes was considered.
C-34. Small, M.M. Natural Sewage Recycling Systems. Brookhaven
National Laboratory Upton, N.Y., 1977.
Previous experiments, indicated that effective treatment of
wastewater can be accomplished through the use of a marsh as a
filtering system. Further studies indicated that a limited
amount of pre-treatment and increased retention times of the
was.tewater within the marsh can increase the effectiveness of
treatment.
C-35. Small, M.M. and C. Wurm. Data Report, Meadow/Marsh System.
Brookhaven National Laboratory, Upton, N.Y., 1977.
Thirteen months of operating data for a natural wastewater
treatment system were summarized.
C-36. Small, M.M. Freshwater from Sewage on Long Island. Brookhaven
National Laboratory, Upton, N.Y. ,1967. : .
A wastewater purification system utilizing natural systems was
found to be an effective method of treatment. Wastewater was
applied to a meadow, where it percolated through the soil into
the groundwatef entering a downstream marsh and, flowed finally,
into a fish-stocked pond.. .'."'"
C-37. Small, M^.M.. Artificial Wetlands as Nonpoint Source Wastewater
Treatment Systems. In: Environmental Quality Through Wetlands
Utilization, Proceedings from a Symposium Sponsored by the
Coordinating Council on the Restoration of the Kissimmee River
Valley and Taylor Creek-Nubbin Slough Basin, February 28-March 2,
1978. Tallahassee, Fla., 1978.
The use of a meadow/marsh/pond natural system for the treatment
of agricultural runoff from individual farms was assessed. The
primary concern was the ability of these small systems to remove
nitrogen and phosphorus to the extent necessary to make them
cost-effective and energy-conservative eutrophication abatement
devices for the Kissimmee agricultural region in Central Florida.
Design parameters were defined for meadow/marsh/pond systems that
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would be capable of meeting the nitrogen and phosphorus effluent
requirements for discharge.
C-38. Spangle'r, F» L., C.W. Fetter, Jr. and W.E. Sloey. Phosphorus
Accumulation-Discharge Cycles in Marshes. Water Res. Bull.
13(6):1191-1201, 1977.
Changes in the quality of polluted waters flowing through
artificial and natural marshes .were monitored. Although
phosphorus was removed by the sediments and plant parts, it was
discharged following the growing season. Recommended methods to
prevent the seasonal discharge of phosphorus into surface waters
included using the discharge water for irrigation on land,
lagooning the water to recycle later, or using conventional
treatment methods.
C-39. Steward, K.K. and W.H. Ornes. Assessing the Capabil ity of the
Everglades Marsh Environment for Renovating Wastewater.
Agricultural Research Service, Fort\Uuderdale, Fla.., 1973.
Simulated effluents were applied to Everglades sawgrass to
determine the feasibility of recycling wastewater through the
marshes. The study indicated that insufficient nutrients were
assimilated to justify the use of the marsh system to renovate
wastewater... ' .
C-40. Sutherland, J.C. and F.B. Bevis. Reuse of Municipal Wastewater
by Volunteer Fresh-Water Wetlands. Proceedings from a Water
Reuse Symposium, \fo-1. 1, March 25-30, 1979. Washington D.C.,
1979. . .
:. The munic ipal.. wastewater treatment system; at Ve'rtno nt v i11e ,
Michigan consists of two facultative stabilization ponds,
followed by four diked, surface-irrigation fields. The
Vermontvilie' system was studied to identify and evaluate any
features that vould make sim.ilar systems feasible alternatives
for economical wastewater treatment for small communities.
C-41. Tilton, D.L. and R»H. Kadlec. The Utilization of a Fresh-Water
Wetland for Nutrient Removal from Secondarily Treated Waste Water
Effluent. Jour. Environ. Qual. 8(3):328-334, 1979.
Secondarily treated wastewater was applied to a wetland in the
northern lower peninsula of Michigan to test the feasibility of
utilizing a freshwater wetland for tertiary wastewater treatment.
Surface water quality, plant productivity, and nutrient status of
plants and -soils were measured.
C-42. Tourbier,;J. and R.W. Pierson, Jr. (eds). Biological Control of
Water Pollution. University of Pennsylvania Press, Philadelphia,
Pa., 1976. . .__': :
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This collection of short articles on the fea-sibil ity of using
higher green plants to purify water was compiled for the
International Conference on Biological Water Quality Improvement
Alternatives. Biological systems were shown to be potentially
effective alternatives or additions to conventional water
treatment systems.
C-43. Valielai I.., J.M. Teal and W. Sass. Nutrient Retention in Salt
Marsh Plots Experimentally Fertilized with Sewage Sludge.
Estuar.. Coast. Marine Sci. 1:261-269, 1973. - ...
Salt marsh experimental plots fertilized with commercially
available sewage sludge were shown to retain substantial amounts
of applied nutrients. The mechanisms by which this occurred,
however, could not be clearly defined.
C-44. Loltek, J. and S.E. Bayley. Remo.yal of Nutrjents. from Treated
Municipal Wastewater by Freshwater" Marshes'. Un i vers:fty of
.Florida, Gainesville, Fla;, 1978. '../:'" :\ '"-' :
The ability of a central Florida freshwater marsh to assimilate
phosphorus and nitrogen from municipal effluent wa:S evaluated.
During the initial year of operation, the marsh plots acted as
efficient tertiary treatment facilities for the removal of
phosphorus and nitrogen.
UPLAND TREATMENT OF WASTEWATER AND STORMWATER
C-45. Aulenbach, D.B. Long Term Recharge of Trickling Filter Effluent
into Sand. U.S. Environmental Pro tec t i o n ;Ag en cy ,
EPA-600/2-79-068, 1979. . :
The Lake George Village, New York, Sewage Treatment Plant, which
applies domestic wastewater that has been subjected to trickling
filter purification and secondary sedimentation to a natural
delta sand deposit by the rapid infiltration method, was studied.
C-46. Deiiham-Blafr and Affiliates, Inc. and Engineering.Enterprises,
Inc. Long-Term Effects of Land Application 0:f Domestic
Wastewater. U.S. Environmental Protection Agency,
EPA-600/2-79-145, 1979 <'
The long-term effects of applying treated domestic wastewater to
an infiltration site at Milton,. Wisconsin, were studied. Water
and soil samples from the site were compared with similar samples
from an upstream control area. Differences between sites in mean
concentrations of 48 parameters were found to be statistically
significant for the effluent applied to the test site as compared
to the ground water at the control site. Soil samples from areas
surrounding the infiltration lagoon indicated that accumulation
of phosphorus, nitrogen and zinc were localized within 150 m of
the infiltration lagoon.
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C-47. Hinesly, L.D., R.E. Thomas and R..G. Stevens. Environmental
Changes from Long-Term Land Applications of Municipal Effluents.
Technical Report for the U.S. Environmental Protection Agency,
1978.
Soil and plant samples collected from sewage effluent disposal
sites during March 1975 at Bakersfield, California, and during
June 1976 at Lubbock, Texas, were analyzed. At both sites,
approximately 16 mgd of effluent is applied daily throughout the
year on land used for the production of raw and forage crops.
Except for changes in phosphorus concentrations, soil chemical
properties were not markedly affected by sewage effluent
irrigations.. Long-term irrigations with sewage effluent caused
very little change in the chemical composition of plants grown on
the disposal sites. ;, '"
C-48. Hook, L.E and L.T. Kardos. Nitrate Leaching during Long-Term
Spray Irrigation for Treatment of Secondary Sewage Effluent on
Woodland Sites. Jour. Environ.. Qual. 7(l):30-34, 1978,,
Nitrate and total nitrogen were measured at two .treated
wastewater discharge sites at the Pennsylvania State .University
Wastewater Renovation Project. The hardwood forest site, which
was irrigated year-round with secondary-municipal .effl uent at a
rate of 5 cm/week, was ineffective in keeping nitrate
concentrations below 10 mg/1. The old field site planted with
white spruce was irrigated from April to November each year with
5 cm/week of effluent, and the nitrate concentration at the 120
cm depth rarely exceeded 10 mg/1.
C-49. J. Jenkins, T.F. and C.J. Martel. Pilot Scale Study of Overland
Flow Land Treatment in Cold Climates. Prog. Wat. Tech.
Il(4-5):207-219,s1979. ....... . ..
The treatment effectiveness of overland flow over a 12-month
period of continuous, .use in a cold temperature climate was
investigated at the'Cold" Regions Research and Engineering
Laboratory, Primary and secondary wastewater were applied to
-.,... separate sections of an overland flow site planted with orchard
.grass and tall fescue. Removal efficiency of suspended solids
remained high throughout the winter, while removal of BOD
declined to unacceptable levels at soil temperatures below 4°C.
Nitrogen removal declined rapidly below 1.4°C, a:nd phosphorus
removal by overland flow, found to be about 80 percent during the
summer months, declined .to zero during the winter months.
C-50. Kemp, M.S., D.I. Filip and O.B. George. Overland Flow and Slow
Rate Systems to Upgrade Wastewater Lagoon Effluent. Prog:. Wat.
Tech. ll(4-5):227-256, 1979. . .
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The minimal BOD and suspended solids removal tha.t were/attained
in this study indicated that overland flow may not be suitable as
a tertiary treatment of effluent at this site. Because of low
soil permeability, the slow rate system was found to be an
excellent tertiary treatment method only if the ground water is
protected and no subsurface water collection and discharge is
required.
C-51. Tee, C.R. and R.E. Peters. Overland Flow Treatment of a
Municipal Lagoon Effluent for Reduction of Nitrogen, Phosphorus,
Heavy Metals and Goliforms. U.S. Corps of Engineer Waterways
Equipment Station, Vicksburg, Miss., 1979.
Overland flow treatment of municipal facultative lagoon effluent
was studied at Utica, Mississippi. Amount of wastewater applied,
length of application period, slo.pe of treatment .area, crop
management, and .reduction in BOD, suspended sol ids-j nitrogen,
phosphorus, heavy metals and col i forms were evaluated. Overland
flow treatment of municipal wastewater was found to produce..grass
yields on marginal agricultural soils' that approached yields
obtained on better agricultural soil.s using normal: irrigation
water. It was also shown to be a viable method for reduction of
nitrogen, phosphorus and heavy metals in municipal wastewater.
C-52. Quin, B.F. Surface Irrigation with Sewage Effluent in New
Zealand: A Case Study. Prog. Wat. Tech. 11(4-5):103-126, 1979.
Twenty years of irrigation of pasture wit-h treated sewage
effluent was shown to have had a decidedly beneficial effect on
the nutrient status of the soil, and on pasture production, which
was 50 percent higher than that of nonirrigated-1 and. The
fertile soil is no longer capable of removing nutrient from the
effluent, however, and nutrients are being lost in the drainage.
C-53. Reynolds, J«H,, M.O. Brown, W.F. Campbell, W. Miller and L>.R.
Anderson. The Long Term Effects.of Land application of
Wastewater. Prog.-Wat. Tech. 11 (4-5):283-300-, 1979.
A site which;had received treated municipal effluent for 20 years
and a site which had been irrigated with normal irrigation water
were compared over a two-year period. Analysis of water quality,
soil characteristics and-plant characteristics .were made to
determine the long-term effects of land applications of
wastewater.
C-54. Scott, T.M. and P.M. Fulton. Removal -of Pollutants in the
Overland Flow (Grass Filtration) System. Prog. Wat. Tech.
11(4-5)301-313, 1979.
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An overland flow land treatment system that has been in operation
at Melbourne, Australia, since the early 1930's was shown to
offer good treatment for BOD, suspended solids, and heavy metals.
Nitrogen and/or phosphorus .removal are critical, however, were
shown to be limited.
C-55. U.S. Environmental Protection Agency. Process Design Manual for
Land Treatment of Municipal Wastewater. EPA 625/1-77-008, 1977.
A rational procedure for the design of land treatment systems was
presented. Slow rate, rapid infiltration and overland flow
processes for the treatment of municipal wastewater were given
emphasis. The basic unit operations and unit processes were
discussed in detail, and the design concepts and criteria were
presented. .
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