1292011
1
Constructed Wetlands
Functions Design Criteria
1292011
2
1292011
3
Functions of Wetlands
bull Flood mitigationbull Flood mitigationbull Water filtrationpurification (treatment)bull Wildlife habitat biodiversitybull Biogeochemical cycles
R tibull Recreation
Reasons for wetland construction
Miti ti Mi i i l f l d dMitigation Mitigation means replacement of wetlands and their functions It is required in the Corps process if alternative siting and efforts to reduce impacts still result in wetland loss
Banking Banking refers to the creation of artificial wetlands storage of ldquocreditsrdquo for these wetlands and subsequent permission to destroy other wetlands with acreages less than the credits banked
Treatment Creation of wetland specifically for purpose of treating a specific waste (eg agricultural runoff storm runoff domestic wastewater mine drainage)
1292011
4
Advantages of Treatment Wetlands
1 Wetlands can be less expensive (both construction operation amp maintenance) than conventional treatment facilities
2 Wetlands can tolerate fluctuations in flow2 Wetlands can tolerate fluctuations in flow3 Wetlands facilitate water reuse and recycling4 Wetlands provide habitat5 Wetlands enhance landscape aesthetics and
functions
Limitationsdisadvantages of wetlands as treatment systems
bull Require large land areasbull Performance may be temporally variable
(temperature floods snowmelt)bull Biological components are susceptible toBiological components are susceptible to
shock loadings (toxics)bull Require minimum amount of water
1292011
5
Important characteristics of wetlands
bull Position in landscapebull Position in landscapebull Water sourcebull Vegetationbull Depth of water tablebull Temporal heterogeneity - variability in p g y y
water level (hydroperiod)bull Spatial heterogeneity - vegetation flow
paths soil or substrate quality
Position in landscape 1
1292011
6
Position in landscape 2
Site SelectionUPLAND
Lowland
bull No permits required for inputsbull Preferred for treatment wetlandsbull Easier to control hydrology
bull Permit required for inputsbull Can restore degraded wetlandsbull Can result in net environmental benefitbullCWA Sec 319 NPS control
Other considerationsOther considerations
bull Public perceptionsbull Role in watershed (water quality wildlife corridors hydrologic)bull Hydrology geomorphology endangered specieshabitat zoning health
1292011
7
Site Selection Criteriabull Historic wetland sitesbull Previously drained or degraded sites of certain wetland types (eg forested or riparian wetlands)bull Sites with reliable adequate and available water supply necessary to provide for proposed wetland functions and valuesbull Sites situated within the landscape such that self-sustaining hydrology can be ensuredbull Sites containing majority of drained or hydrologically modified hydric soilsbull Sites with predominately hydric or hydrologically modified soilsbull Sites in close proximity to designated priority areas such as state management areas public lands preservesbull Sites connected to existing wetland systems andor areas of wildlife significancebull Sites with sufficient distance from incompatible land uses andor urban or populated areas that may reduce long-term wetland functioningbull Sites that contain adequate associated upland areas to serve as a wetland bufferbull Sites in which construction will not adversely affect ecologically significant aquatic or upland areas cultural sites or habitat for threatened and endangered speciesorbull Sites that will enhance habitat and species diversity outdoor recreation and scientific and research valuesEnviron Law Inst (ELI) 2002 Banking and Fees
VegetationObjectivesbull Maximize species diversitybull Maximize genetic diversityMaximize genetic diversitybullOptimize wildlife habitat
StrategiesMi i i ldquo d rdquo i di i i ibull Minimize ldquoweedyrdquo nonindigenous or invasive species
bull Use local indigenous speciesbull Optimize physical heterogeneitybull Create temporal variations in flowbull Use multiple ldquocellsrdquobull Plan capacity for sediment accumulation
1292011
8
Reasons for constructing wetlandswetlands
1 Mitigation (replacement of destroyed wetlands)2 Banking2 NPS pollution control2 NPS pollution control3 Point source pollution treatment (sewage storm water runoff
acid mine drainage ldquoindustrialrdquo waste)4 Wildlife habitat5 Wetland restoration
Flow regimes in constructed wetlands
S f flSurface flow ndasheasier but require more areatemporally amp spatially variable
Subsurface flow saturated ndashlargely anaerobic
Subsurface flow unsaturated ndashhorizontal trickling filter both aerobic andanaerobic
1292011
9
Flow regimes cell layout
Surface feed unsaturated subsurface flow
1292011
10
Subsurface flow
Surface feedsurface flow
1292011
11
Performance Potential
Frequent pollutants1 Sediments - 1) settling basin design τmin gt settling
time 2) sediment accumulation ratedictates storage capacity (dredging willdictates storage capacity (dredging willrequire CWA sec 404 permit as well aseasy access) Short circuiting of flow isproblematic avoid scouring
2 Nitrogen ndash two removal mechanisms 1) burial of organic N2) d it ifi ti T fi t h i i i2) denitrification To use first mechanism maximizeplant growth and sediment accumulation (saturated soil)For denitrification anaerobic zones without shortcircuiting are important subsurface feed and flow aredesirable For feed lots initial nitrification may requireaerated flow
1292011
12
Further pollutantsPhosphorus ndash primary removal mechanisms are burial of organic
matter and sorption on oxic soils Maximize organicmatter preservation (anaerobic soils) sedimentaccumulation rate and areas with oxic sediments avoidshort circuiting ndash multiple cells desirable
Vectors amp pathogens1 Mosquitoes ndash minimize stagnant water
- utilize natural predators2 Bacteria ndash retention time adequate to kill bacteria
base on low temperature conditions- solids filtration (subsurface flow) and settling
Processes in wetlands
1292011
13
Empirical design criteria
1292011
14
Quasi-mechanistic design criteria
1 Hydrology Q ndash Q + PmiddotA - ETA = dVdt1 Hydrology Qin ndash Qout + P A - ET A = dVdt1 Darcyrsquos Law Q = KA(dhdx)
2 BOD or bacteria removal
( )175
2
3
1exp refT Tv
o
v
C A k A L w dC Q
mA specific area for bacterial growth
θ φminus⎛ ⎞= sdot minus sdot sdot sdot sdot sdot sdot sdot⎜ ⎟
⎝ ⎠⎛ ⎞
= sdot sdot sdot sdot sdot⎜ ⎟⎝ ⎠
3
dim
v p f f gm
L w d physical ensionsporosityφ
⎜ ⎟⎝ ⎠
= sdot=
Constructed Wetland or Pond
1292011
15
What functions are fulfilled
Wetland or lagoon or pond
1292011
16
References
1 U S EPA 6261-88022 Sept 1988 Design Manual1 US EPA 6261-88022 Sept 1988 Design Manual Constructed wetlands and aquatic plant systems for municipal wastewater treatment
2 Moshiri GA (ed) 1993 Constructed wetlands for water quality improvement CRC Press Boca Raton FL 632 pp
3 Hammer DA (ed) 1989 Constructed wetlands for wastewater treatment Municipal Industrial and Agricultural Lewis p g Publishers Chelsea MI 831 pp
4 Hammer DA 1997 Creating Freshwater Wetlands 2nd ed CRC Press Boca Raton FL 406 pp
1292011
2
1292011
3
Functions of Wetlands
bull Flood mitigationbull Flood mitigationbull Water filtrationpurification (treatment)bull Wildlife habitat biodiversitybull Biogeochemical cycles
R tibull Recreation
Reasons for wetland construction
Miti ti Mi i i l f l d dMitigation Mitigation means replacement of wetlands and their functions It is required in the Corps process if alternative siting and efforts to reduce impacts still result in wetland loss
Banking Banking refers to the creation of artificial wetlands storage of ldquocreditsrdquo for these wetlands and subsequent permission to destroy other wetlands with acreages less than the credits banked
Treatment Creation of wetland specifically for purpose of treating a specific waste (eg agricultural runoff storm runoff domestic wastewater mine drainage)
1292011
4
Advantages of Treatment Wetlands
1 Wetlands can be less expensive (both construction operation amp maintenance) than conventional treatment facilities
2 Wetlands can tolerate fluctuations in flow2 Wetlands can tolerate fluctuations in flow3 Wetlands facilitate water reuse and recycling4 Wetlands provide habitat5 Wetlands enhance landscape aesthetics and
functions
Limitationsdisadvantages of wetlands as treatment systems
bull Require large land areasbull Performance may be temporally variable
(temperature floods snowmelt)bull Biological components are susceptible toBiological components are susceptible to
shock loadings (toxics)bull Require minimum amount of water
1292011
5
Important characteristics of wetlands
bull Position in landscapebull Position in landscapebull Water sourcebull Vegetationbull Depth of water tablebull Temporal heterogeneity - variability in p g y y
water level (hydroperiod)bull Spatial heterogeneity - vegetation flow
paths soil or substrate quality
Position in landscape 1
1292011
6
Position in landscape 2
Site SelectionUPLAND
Lowland
bull No permits required for inputsbull Preferred for treatment wetlandsbull Easier to control hydrology
bull Permit required for inputsbull Can restore degraded wetlandsbull Can result in net environmental benefitbullCWA Sec 319 NPS control
Other considerationsOther considerations
bull Public perceptionsbull Role in watershed (water quality wildlife corridors hydrologic)bull Hydrology geomorphology endangered specieshabitat zoning health
1292011
7
Site Selection Criteriabull Historic wetland sitesbull Previously drained or degraded sites of certain wetland types (eg forested or riparian wetlands)bull Sites with reliable adequate and available water supply necessary to provide for proposed wetland functions and valuesbull Sites situated within the landscape such that self-sustaining hydrology can be ensuredbull Sites containing majority of drained or hydrologically modified hydric soilsbull Sites with predominately hydric or hydrologically modified soilsbull Sites in close proximity to designated priority areas such as state management areas public lands preservesbull Sites connected to existing wetland systems andor areas of wildlife significancebull Sites with sufficient distance from incompatible land uses andor urban or populated areas that may reduce long-term wetland functioningbull Sites that contain adequate associated upland areas to serve as a wetland bufferbull Sites in which construction will not adversely affect ecologically significant aquatic or upland areas cultural sites or habitat for threatened and endangered speciesorbull Sites that will enhance habitat and species diversity outdoor recreation and scientific and research valuesEnviron Law Inst (ELI) 2002 Banking and Fees
VegetationObjectivesbull Maximize species diversitybull Maximize genetic diversityMaximize genetic diversitybullOptimize wildlife habitat
StrategiesMi i i ldquo d rdquo i di i i ibull Minimize ldquoweedyrdquo nonindigenous or invasive species
bull Use local indigenous speciesbull Optimize physical heterogeneitybull Create temporal variations in flowbull Use multiple ldquocellsrdquobull Plan capacity for sediment accumulation
1292011
8
Reasons for constructing wetlandswetlands
1 Mitigation (replacement of destroyed wetlands)2 Banking2 NPS pollution control2 NPS pollution control3 Point source pollution treatment (sewage storm water runoff
acid mine drainage ldquoindustrialrdquo waste)4 Wildlife habitat5 Wetland restoration
Flow regimes in constructed wetlands
S f flSurface flow ndasheasier but require more areatemporally amp spatially variable
Subsurface flow saturated ndashlargely anaerobic
Subsurface flow unsaturated ndashhorizontal trickling filter both aerobic andanaerobic
1292011
9
Flow regimes cell layout
Surface feed unsaturated subsurface flow
1292011
10
Subsurface flow
Surface feedsurface flow
1292011
11
Performance Potential
Frequent pollutants1 Sediments - 1) settling basin design τmin gt settling
time 2) sediment accumulation ratedictates storage capacity (dredging willdictates storage capacity (dredging willrequire CWA sec 404 permit as well aseasy access) Short circuiting of flow isproblematic avoid scouring
2 Nitrogen ndash two removal mechanisms 1) burial of organic N2) d it ifi ti T fi t h i i i2) denitrification To use first mechanism maximizeplant growth and sediment accumulation (saturated soil)For denitrification anaerobic zones without shortcircuiting are important subsurface feed and flow aredesirable For feed lots initial nitrification may requireaerated flow
1292011
12
Further pollutantsPhosphorus ndash primary removal mechanisms are burial of organic
matter and sorption on oxic soils Maximize organicmatter preservation (anaerobic soils) sedimentaccumulation rate and areas with oxic sediments avoidshort circuiting ndash multiple cells desirable
Vectors amp pathogens1 Mosquitoes ndash minimize stagnant water
- utilize natural predators2 Bacteria ndash retention time adequate to kill bacteria
base on low temperature conditions- solids filtration (subsurface flow) and settling
Processes in wetlands
1292011
13
Empirical design criteria
1292011
14
Quasi-mechanistic design criteria
1 Hydrology Q ndash Q + PmiddotA - ETA = dVdt1 Hydrology Qin ndash Qout + P A - ET A = dVdt1 Darcyrsquos Law Q = KA(dhdx)
2 BOD or bacteria removal
( )175
2
3
1exp refT Tv
o
v
C A k A L w dC Q
mA specific area for bacterial growth
θ φminus⎛ ⎞= sdot minus sdot sdot sdot sdot sdot sdot sdot⎜ ⎟
⎝ ⎠⎛ ⎞
= sdot sdot sdot sdot sdot⎜ ⎟⎝ ⎠
3
dim
v p f f gm
L w d physical ensionsporosityφ
⎜ ⎟⎝ ⎠
= sdot=
Constructed Wetland or Pond
1292011
15
What functions are fulfilled
Wetland or lagoon or pond
1292011
16
References
1 U S EPA 6261-88022 Sept 1988 Design Manual1 US EPA 6261-88022 Sept 1988 Design Manual Constructed wetlands and aquatic plant systems for municipal wastewater treatment
2 Moshiri GA (ed) 1993 Constructed wetlands for water quality improvement CRC Press Boca Raton FL 632 pp
3 Hammer DA (ed) 1989 Constructed wetlands for wastewater treatment Municipal Industrial and Agricultural Lewis p g Publishers Chelsea MI 831 pp
4 Hammer DA 1997 Creating Freshwater Wetlands 2nd ed CRC Press Boca Raton FL 406 pp
1292011
3
Functions of Wetlands
bull Flood mitigationbull Flood mitigationbull Water filtrationpurification (treatment)bull Wildlife habitat biodiversitybull Biogeochemical cycles
R tibull Recreation
Reasons for wetland construction
Miti ti Mi i i l f l d dMitigation Mitigation means replacement of wetlands and their functions It is required in the Corps process if alternative siting and efforts to reduce impacts still result in wetland loss
Banking Banking refers to the creation of artificial wetlands storage of ldquocreditsrdquo for these wetlands and subsequent permission to destroy other wetlands with acreages less than the credits banked
Treatment Creation of wetland specifically for purpose of treating a specific waste (eg agricultural runoff storm runoff domestic wastewater mine drainage)
1292011
4
Advantages of Treatment Wetlands
1 Wetlands can be less expensive (both construction operation amp maintenance) than conventional treatment facilities
2 Wetlands can tolerate fluctuations in flow2 Wetlands can tolerate fluctuations in flow3 Wetlands facilitate water reuse and recycling4 Wetlands provide habitat5 Wetlands enhance landscape aesthetics and
functions
Limitationsdisadvantages of wetlands as treatment systems
bull Require large land areasbull Performance may be temporally variable
(temperature floods snowmelt)bull Biological components are susceptible toBiological components are susceptible to
shock loadings (toxics)bull Require minimum amount of water
1292011
5
Important characteristics of wetlands
bull Position in landscapebull Position in landscapebull Water sourcebull Vegetationbull Depth of water tablebull Temporal heterogeneity - variability in p g y y
water level (hydroperiod)bull Spatial heterogeneity - vegetation flow
paths soil or substrate quality
Position in landscape 1
1292011
6
Position in landscape 2
Site SelectionUPLAND
Lowland
bull No permits required for inputsbull Preferred for treatment wetlandsbull Easier to control hydrology
bull Permit required for inputsbull Can restore degraded wetlandsbull Can result in net environmental benefitbullCWA Sec 319 NPS control
Other considerationsOther considerations
bull Public perceptionsbull Role in watershed (water quality wildlife corridors hydrologic)bull Hydrology geomorphology endangered specieshabitat zoning health
1292011
7
Site Selection Criteriabull Historic wetland sitesbull Previously drained or degraded sites of certain wetland types (eg forested or riparian wetlands)bull Sites with reliable adequate and available water supply necessary to provide for proposed wetland functions and valuesbull Sites situated within the landscape such that self-sustaining hydrology can be ensuredbull Sites containing majority of drained or hydrologically modified hydric soilsbull Sites with predominately hydric or hydrologically modified soilsbull Sites in close proximity to designated priority areas such as state management areas public lands preservesbull Sites connected to existing wetland systems andor areas of wildlife significancebull Sites with sufficient distance from incompatible land uses andor urban or populated areas that may reduce long-term wetland functioningbull Sites that contain adequate associated upland areas to serve as a wetland bufferbull Sites in which construction will not adversely affect ecologically significant aquatic or upland areas cultural sites or habitat for threatened and endangered speciesorbull Sites that will enhance habitat and species diversity outdoor recreation and scientific and research valuesEnviron Law Inst (ELI) 2002 Banking and Fees
VegetationObjectivesbull Maximize species diversitybull Maximize genetic diversityMaximize genetic diversitybullOptimize wildlife habitat
StrategiesMi i i ldquo d rdquo i di i i ibull Minimize ldquoweedyrdquo nonindigenous or invasive species
bull Use local indigenous speciesbull Optimize physical heterogeneitybull Create temporal variations in flowbull Use multiple ldquocellsrdquobull Plan capacity for sediment accumulation
1292011
8
Reasons for constructing wetlandswetlands
1 Mitigation (replacement of destroyed wetlands)2 Banking2 NPS pollution control2 NPS pollution control3 Point source pollution treatment (sewage storm water runoff
acid mine drainage ldquoindustrialrdquo waste)4 Wildlife habitat5 Wetland restoration
Flow regimes in constructed wetlands
S f flSurface flow ndasheasier but require more areatemporally amp spatially variable
Subsurface flow saturated ndashlargely anaerobic
Subsurface flow unsaturated ndashhorizontal trickling filter both aerobic andanaerobic
1292011
9
Flow regimes cell layout
Surface feed unsaturated subsurface flow
1292011
10
Subsurface flow
Surface feedsurface flow
1292011
11
Performance Potential
Frequent pollutants1 Sediments - 1) settling basin design τmin gt settling
time 2) sediment accumulation ratedictates storage capacity (dredging willdictates storage capacity (dredging willrequire CWA sec 404 permit as well aseasy access) Short circuiting of flow isproblematic avoid scouring
2 Nitrogen ndash two removal mechanisms 1) burial of organic N2) d it ifi ti T fi t h i i i2) denitrification To use first mechanism maximizeplant growth and sediment accumulation (saturated soil)For denitrification anaerobic zones without shortcircuiting are important subsurface feed and flow aredesirable For feed lots initial nitrification may requireaerated flow
1292011
12
Further pollutantsPhosphorus ndash primary removal mechanisms are burial of organic
matter and sorption on oxic soils Maximize organicmatter preservation (anaerobic soils) sedimentaccumulation rate and areas with oxic sediments avoidshort circuiting ndash multiple cells desirable
Vectors amp pathogens1 Mosquitoes ndash minimize stagnant water
- utilize natural predators2 Bacteria ndash retention time adequate to kill bacteria
base on low temperature conditions- solids filtration (subsurface flow) and settling
Processes in wetlands
1292011
13
Empirical design criteria
1292011
14
Quasi-mechanistic design criteria
1 Hydrology Q ndash Q + PmiddotA - ETA = dVdt1 Hydrology Qin ndash Qout + P A - ET A = dVdt1 Darcyrsquos Law Q = KA(dhdx)
2 BOD or bacteria removal
( )175
2
3
1exp refT Tv
o
v
C A k A L w dC Q
mA specific area for bacterial growth
θ φminus⎛ ⎞= sdot minus sdot sdot sdot sdot sdot sdot sdot⎜ ⎟
⎝ ⎠⎛ ⎞
= sdot sdot sdot sdot sdot⎜ ⎟⎝ ⎠
3
dim
v p f f gm
L w d physical ensionsporosityφ
⎜ ⎟⎝ ⎠
= sdot=
Constructed Wetland or Pond
1292011
15
What functions are fulfilled
Wetland or lagoon or pond
1292011
16
References
1 U S EPA 6261-88022 Sept 1988 Design Manual1 US EPA 6261-88022 Sept 1988 Design Manual Constructed wetlands and aquatic plant systems for municipal wastewater treatment
2 Moshiri GA (ed) 1993 Constructed wetlands for water quality improvement CRC Press Boca Raton FL 632 pp
3 Hammer DA (ed) 1989 Constructed wetlands for wastewater treatment Municipal Industrial and Agricultural Lewis p g Publishers Chelsea MI 831 pp
4 Hammer DA 1997 Creating Freshwater Wetlands 2nd ed CRC Press Boca Raton FL 406 pp
1292011
4
Advantages of Treatment Wetlands
1 Wetlands can be less expensive (both construction operation amp maintenance) than conventional treatment facilities
2 Wetlands can tolerate fluctuations in flow2 Wetlands can tolerate fluctuations in flow3 Wetlands facilitate water reuse and recycling4 Wetlands provide habitat5 Wetlands enhance landscape aesthetics and
functions
Limitationsdisadvantages of wetlands as treatment systems
bull Require large land areasbull Performance may be temporally variable
(temperature floods snowmelt)bull Biological components are susceptible toBiological components are susceptible to
shock loadings (toxics)bull Require minimum amount of water
1292011
5
Important characteristics of wetlands
bull Position in landscapebull Position in landscapebull Water sourcebull Vegetationbull Depth of water tablebull Temporal heterogeneity - variability in p g y y
water level (hydroperiod)bull Spatial heterogeneity - vegetation flow
paths soil or substrate quality
Position in landscape 1
1292011
6
Position in landscape 2
Site SelectionUPLAND
Lowland
bull No permits required for inputsbull Preferred for treatment wetlandsbull Easier to control hydrology
bull Permit required for inputsbull Can restore degraded wetlandsbull Can result in net environmental benefitbullCWA Sec 319 NPS control
Other considerationsOther considerations
bull Public perceptionsbull Role in watershed (water quality wildlife corridors hydrologic)bull Hydrology geomorphology endangered specieshabitat zoning health
1292011
7
Site Selection Criteriabull Historic wetland sitesbull Previously drained or degraded sites of certain wetland types (eg forested or riparian wetlands)bull Sites with reliable adequate and available water supply necessary to provide for proposed wetland functions and valuesbull Sites situated within the landscape such that self-sustaining hydrology can be ensuredbull Sites containing majority of drained or hydrologically modified hydric soilsbull Sites with predominately hydric or hydrologically modified soilsbull Sites in close proximity to designated priority areas such as state management areas public lands preservesbull Sites connected to existing wetland systems andor areas of wildlife significancebull Sites with sufficient distance from incompatible land uses andor urban or populated areas that may reduce long-term wetland functioningbull Sites that contain adequate associated upland areas to serve as a wetland bufferbull Sites in which construction will not adversely affect ecologically significant aquatic or upland areas cultural sites or habitat for threatened and endangered speciesorbull Sites that will enhance habitat and species diversity outdoor recreation and scientific and research valuesEnviron Law Inst (ELI) 2002 Banking and Fees
VegetationObjectivesbull Maximize species diversitybull Maximize genetic diversityMaximize genetic diversitybullOptimize wildlife habitat
StrategiesMi i i ldquo d rdquo i di i i ibull Minimize ldquoweedyrdquo nonindigenous or invasive species
bull Use local indigenous speciesbull Optimize physical heterogeneitybull Create temporal variations in flowbull Use multiple ldquocellsrdquobull Plan capacity for sediment accumulation
1292011
8
Reasons for constructing wetlandswetlands
1 Mitigation (replacement of destroyed wetlands)2 Banking2 NPS pollution control2 NPS pollution control3 Point source pollution treatment (sewage storm water runoff
acid mine drainage ldquoindustrialrdquo waste)4 Wildlife habitat5 Wetland restoration
Flow regimes in constructed wetlands
S f flSurface flow ndasheasier but require more areatemporally amp spatially variable
Subsurface flow saturated ndashlargely anaerobic
Subsurface flow unsaturated ndashhorizontal trickling filter both aerobic andanaerobic
1292011
9
Flow regimes cell layout
Surface feed unsaturated subsurface flow
1292011
10
Subsurface flow
Surface feedsurface flow
1292011
11
Performance Potential
Frequent pollutants1 Sediments - 1) settling basin design τmin gt settling
time 2) sediment accumulation ratedictates storage capacity (dredging willdictates storage capacity (dredging willrequire CWA sec 404 permit as well aseasy access) Short circuiting of flow isproblematic avoid scouring
2 Nitrogen ndash two removal mechanisms 1) burial of organic N2) d it ifi ti T fi t h i i i2) denitrification To use first mechanism maximizeplant growth and sediment accumulation (saturated soil)For denitrification anaerobic zones without shortcircuiting are important subsurface feed and flow aredesirable For feed lots initial nitrification may requireaerated flow
1292011
12
Further pollutantsPhosphorus ndash primary removal mechanisms are burial of organic
matter and sorption on oxic soils Maximize organicmatter preservation (anaerobic soils) sedimentaccumulation rate and areas with oxic sediments avoidshort circuiting ndash multiple cells desirable
Vectors amp pathogens1 Mosquitoes ndash minimize stagnant water
- utilize natural predators2 Bacteria ndash retention time adequate to kill bacteria
base on low temperature conditions- solids filtration (subsurface flow) and settling
Processes in wetlands
1292011
13
Empirical design criteria
1292011
14
Quasi-mechanistic design criteria
1 Hydrology Q ndash Q + PmiddotA - ETA = dVdt1 Hydrology Qin ndash Qout + P A - ET A = dVdt1 Darcyrsquos Law Q = KA(dhdx)
2 BOD or bacteria removal
( )175
2
3
1exp refT Tv
o
v
C A k A L w dC Q
mA specific area for bacterial growth
θ φminus⎛ ⎞= sdot minus sdot sdot sdot sdot sdot sdot sdot⎜ ⎟
⎝ ⎠⎛ ⎞
= sdot sdot sdot sdot sdot⎜ ⎟⎝ ⎠
3
dim
v p f f gm
L w d physical ensionsporosityφ
⎜ ⎟⎝ ⎠
= sdot=
Constructed Wetland or Pond
1292011
15
What functions are fulfilled
Wetland or lagoon or pond
1292011
16
References
1 U S EPA 6261-88022 Sept 1988 Design Manual1 US EPA 6261-88022 Sept 1988 Design Manual Constructed wetlands and aquatic plant systems for municipal wastewater treatment
2 Moshiri GA (ed) 1993 Constructed wetlands for water quality improvement CRC Press Boca Raton FL 632 pp
3 Hammer DA (ed) 1989 Constructed wetlands for wastewater treatment Municipal Industrial and Agricultural Lewis p g Publishers Chelsea MI 831 pp
4 Hammer DA 1997 Creating Freshwater Wetlands 2nd ed CRC Press Boca Raton FL 406 pp
1292011
5
Important characteristics of wetlands
bull Position in landscapebull Position in landscapebull Water sourcebull Vegetationbull Depth of water tablebull Temporal heterogeneity - variability in p g y y
water level (hydroperiod)bull Spatial heterogeneity - vegetation flow
paths soil or substrate quality
Position in landscape 1
1292011
6
Position in landscape 2
Site SelectionUPLAND
Lowland
bull No permits required for inputsbull Preferred for treatment wetlandsbull Easier to control hydrology
bull Permit required for inputsbull Can restore degraded wetlandsbull Can result in net environmental benefitbullCWA Sec 319 NPS control
Other considerationsOther considerations
bull Public perceptionsbull Role in watershed (water quality wildlife corridors hydrologic)bull Hydrology geomorphology endangered specieshabitat zoning health
1292011
7
Site Selection Criteriabull Historic wetland sitesbull Previously drained or degraded sites of certain wetland types (eg forested or riparian wetlands)bull Sites with reliable adequate and available water supply necessary to provide for proposed wetland functions and valuesbull Sites situated within the landscape such that self-sustaining hydrology can be ensuredbull Sites containing majority of drained or hydrologically modified hydric soilsbull Sites with predominately hydric or hydrologically modified soilsbull Sites in close proximity to designated priority areas such as state management areas public lands preservesbull Sites connected to existing wetland systems andor areas of wildlife significancebull Sites with sufficient distance from incompatible land uses andor urban or populated areas that may reduce long-term wetland functioningbull Sites that contain adequate associated upland areas to serve as a wetland bufferbull Sites in which construction will not adversely affect ecologically significant aquatic or upland areas cultural sites or habitat for threatened and endangered speciesorbull Sites that will enhance habitat and species diversity outdoor recreation and scientific and research valuesEnviron Law Inst (ELI) 2002 Banking and Fees
VegetationObjectivesbull Maximize species diversitybull Maximize genetic diversityMaximize genetic diversitybullOptimize wildlife habitat
StrategiesMi i i ldquo d rdquo i di i i ibull Minimize ldquoweedyrdquo nonindigenous or invasive species
bull Use local indigenous speciesbull Optimize physical heterogeneitybull Create temporal variations in flowbull Use multiple ldquocellsrdquobull Plan capacity for sediment accumulation
1292011
8
Reasons for constructing wetlandswetlands
1 Mitigation (replacement of destroyed wetlands)2 Banking2 NPS pollution control2 NPS pollution control3 Point source pollution treatment (sewage storm water runoff
acid mine drainage ldquoindustrialrdquo waste)4 Wildlife habitat5 Wetland restoration
Flow regimes in constructed wetlands
S f flSurface flow ndasheasier but require more areatemporally amp spatially variable
Subsurface flow saturated ndashlargely anaerobic
Subsurface flow unsaturated ndashhorizontal trickling filter both aerobic andanaerobic
1292011
9
Flow regimes cell layout
Surface feed unsaturated subsurface flow
1292011
10
Subsurface flow
Surface feedsurface flow
1292011
11
Performance Potential
Frequent pollutants1 Sediments - 1) settling basin design τmin gt settling
time 2) sediment accumulation ratedictates storage capacity (dredging willdictates storage capacity (dredging willrequire CWA sec 404 permit as well aseasy access) Short circuiting of flow isproblematic avoid scouring
2 Nitrogen ndash two removal mechanisms 1) burial of organic N2) d it ifi ti T fi t h i i i2) denitrification To use first mechanism maximizeplant growth and sediment accumulation (saturated soil)For denitrification anaerobic zones without shortcircuiting are important subsurface feed and flow aredesirable For feed lots initial nitrification may requireaerated flow
1292011
12
Further pollutantsPhosphorus ndash primary removal mechanisms are burial of organic
matter and sorption on oxic soils Maximize organicmatter preservation (anaerobic soils) sedimentaccumulation rate and areas with oxic sediments avoidshort circuiting ndash multiple cells desirable
Vectors amp pathogens1 Mosquitoes ndash minimize stagnant water
- utilize natural predators2 Bacteria ndash retention time adequate to kill bacteria
base on low temperature conditions- solids filtration (subsurface flow) and settling
Processes in wetlands
1292011
13
Empirical design criteria
1292011
14
Quasi-mechanistic design criteria
1 Hydrology Q ndash Q + PmiddotA - ETA = dVdt1 Hydrology Qin ndash Qout + P A - ET A = dVdt1 Darcyrsquos Law Q = KA(dhdx)
2 BOD or bacteria removal
( )175
2
3
1exp refT Tv
o
v
C A k A L w dC Q
mA specific area for bacterial growth
θ φminus⎛ ⎞= sdot minus sdot sdot sdot sdot sdot sdot sdot⎜ ⎟
⎝ ⎠⎛ ⎞
= sdot sdot sdot sdot sdot⎜ ⎟⎝ ⎠
3
dim
v p f f gm
L w d physical ensionsporosityφ
⎜ ⎟⎝ ⎠
= sdot=
Constructed Wetland or Pond
1292011
15
What functions are fulfilled
Wetland or lagoon or pond
1292011
16
References
1 U S EPA 6261-88022 Sept 1988 Design Manual1 US EPA 6261-88022 Sept 1988 Design Manual Constructed wetlands and aquatic plant systems for municipal wastewater treatment
2 Moshiri GA (ed) 1993 Constructed wetlands for water quality improvement CRC Press Boca Raton FL 632 pp
3 Hammer DA (ed) 1989 Constructed wetlands for wastewater treatment Municipal Industrial and Agricultural Lewis p g Publishers Chelsea MI 831 pp
4 Hammer DA 1997 Creating Freshwater Wetlands 2nd ed CRC Press Boca Raton FL 406 pp
1292011
6
Position in landscape 2
Site SelectionUPLAND
Lowland
bull No permits required for inputsbull Preferred for treatment wetlandsbull Easier to control hydrology
bull Permit required for inputsbull Can restore degraded wetlandsbull Can result in net environmental benefitbullCWA Sec 319 NPS control
Other considerationsOther considerations
bull Public perceptionsbull Role in watershed (water quality wildlife corridors hydrologic)bull Hydrology geomorphology endangered specieshabitat zoning health
1292011
7
Site Selection Criteriabull Historic wetland sitesbull Previously drained or degraded sites of certain wetland types (eg forested or riparian wetlands)bull Sites with reliable adequate and available water supply necessary to provide for proposed wetland functions and valuesbull Sites situated within the landscape such that self-sustaining hydrology can be ensuredbull Sites containing majority of drained or hydrologically modified hydric soilsbull Sites with predominately hydric or hydrologically modified soilsbull Sites in close proximity to designated priority areas such as state management areas public lands preservesbull Sites connected to existing wetland systems andor areas of wildlife significancebull Sites with sufficient distance from incompatible land uses andor urban or populated areas that may reduce long-term wetland functioningbull Sites that contain adequate associated upland areas to serve as a wetland bufferbull Sites in which construction will not adversely affect ecologically significant aquatic or upland areas cultural sites or habitat for threatened and endangered speciesorbull Sites that will enhance habitat and species diversity outdoor recreation and scientific and research valuesEnviron Law Inst (ELI) 2002 Banking and Fees
VegetationObjectivesbull Maximize species diversitybull Maximize genetic diversityMaximize genetic diversitybullOptimize wildlife habitat
StrategiesMi i i ldquo d rdquo i di i i ibull Minimize ldquoweedyrdquo nonindigenous or invasive species
bull Use local indigenous speciesbull Optimize physical heterogeneitybull Create temporal variations in flowbull Use multiple ldquocellsrdquobull Plan capacity for sediment accumulation
1292011
8
Reasons for constructing wetlandswetlands
1 Mitigation (replacement of destroyed wetlands)2 Banking2 NPS pollution control2 NPS pollution control3 Point source pollution treatment (sewage storm water runoff
acid mine drainage ldquoindustrialrdquo waste)4 Wildlife habitat5 Wetland restoration
Flow regimes in constructed wetlands
S f flSurface flow ndasheasier but require more areatemporally amp spatially variable
Subsurface flow saturated ndashlargely anaerobic
Subsurface flow unsaturated ndashhorizontal trickling filter both aerobic andanaerobic
1292011
9
Flow regimes cell layout
Surface feed unsaturated subsurface flow
1292011
10
Subsurface flow
Surface feedsurface flow
1292011
11
Performance Potential
Frequent pollutants1 Sediments - 1) settling basin design τmin gt settling
time 2) sediment accumulation ratedictates storage capacity (dredging willdictates storage capacity (dredging willrequire CWA sec 404 permit as well aseasy access) Short circuiting of flow isproblematic avoid scouring
2 Nitrogen ndash two removal mechanisms 1) burial of organic N2) d it ifi ti T fi t h i i i2) denitrification To use first mechanism maximizeplant growth and sediment accumulation (saturated soil)For denitrification anaerobic zones without shortcircuiting are important subsurface feed and flow aredesirable For feed lots initial nitrification may requireaerated flow
1292011
12
Further pollutantsPhosphorus ndash primary removal mechanisms are burial of organic
matter and sorption on oxic soils Maximize organicmatter preservation (anaerobic soils) sedimentaccumulation rate and areas with oxic sediments avoidshort circuiting ndash multiple cells desirable
Vectors amp pathogens1 Mosquitoes ndash minimize stagnant water
- utilize natural predators2 Bacteria ndash retention time adequate to kill bacteria
base on low temperature conditions- solids filtration (subsurface flow) and settling
Processes in wetlands
1292011
13
Empirical design criteria
1292011
14
Quasi-mechanistic design criteria
1 Hydrology Q ndash Q + PmiddotA - ETA = dVdt1 Hydrology Qin ndash Qout + P A - ET A = dVdt1 Darcyrsquos Law Q = KA(dhdx)
2 BOD or bacteria removal
( )175
2
3
1exp refT Tv
o
v
C A k A L w dC Q
mA specific area for bacterial growth
θ φminus⎛ ⎞= sdot minus sdot sdot sdot sdot sdot sdot sdot⎜ ⎟
⎝ ⎠⎛ ⎞
= sdot sdot sdot sdot sdot⎜ ⎟⎝ ⎠
3
dim
v p f f gm
L w d physical ensionsporosityφ
⎜ ⎟⎝ ⎠
= sdot=
Constructed Wetland or Pond
1292011
15
What functions are fulfilled
Wetland or lagoon or pond
1292011
16
References
1 U S EPA 6261-88022 Sept 1988 Design Manual1 US EPA 6261-88022 Sept 1988 Design Manual Constructed wetlands and aquatic plant systems for municipal wastewater treatment
2 Moshiri GA (ed) 1993 Constructed wetlands for water quality improvement CRC Press Boca Raton FL 632 pp
3 Hammer DA (ed) 1989 Constructed wetlands for wastewater treatment Municipal Industrial and Agricultural Lewis p g Publishers Chelsea MI 831 pp
4 Hammer DA 1997 Creating Freshwater Wetlands 2nd ed CRC Press Boca Raton FL 406 pp
1292011
7
Site Selection Criteriabull Historic wetland sitesbull Previously drained or degraded sites of certain wetland types (eg forested or riparian wetlands)bull Sites with reliable adequate and available water supply necessary to provide for proposed wetland functions and valuesbull Sites situated within the landscape such that self-sustaining hydrology can be ensuredbull Sites containing majority of drained or hydrologically modified hydric soilsbull Sites with predominately hydric or hydrologically modified soilsbull Sites in close proximity to designated priority areas such as state management areas public lands preservesbull Sites connected to existing wetland systems andor areas of wildlife significancebull Sites with sufficient distance from incompatible land uses andor urban or populated areas that may reduce long-term wetland functioningbull Sites that contain adequate associated upland areas to serve as a wetland bufferbull Sites in which construction will not adversely affect ecologically significant aquatic or upland areas cultural sites or habitat for threatened and endangered speciesorbull Sites that will enhance habitat and species diversity outdoor recreation and scientific and research valuesEnviron Law Inst (ELI) 2002 Banking and Fees
VegetationObjectivesbull Maximize species diversitybull Maximize genetic diversityMaximize genetic diversitybullOptimize wildlife habitat
StrategiesMi i i ldquo d rdquo i di i i ibull Minimize ldquoweedyrdquo nonindigenous or invasive species
bull Use local indigenous speciesbull Optimize physical heterogeneitybull Create temporal variations in flowbull Use multiple ldquocellsrdquobull Plan capacity for sediment accumulation
1292011
8
Reasons for constructing wetlandswetlands
1 Mitigation (replacement of destroyed wetlands)2 Banking2 NPS pollution control2 NPS pollution control3 Point source pollution treatment (sewage storm water runoff
acid mine drainage ldquoindustrialrdquo waste)4 Wildlife habitat5 Wetland restoration
Flow regimes in constructed wetlands
S f flSurface flow ndasheasier but require more areatemporally amp spatially variable
Subsurface flow saturated ndashlargely anaerobic
Subsurface flow unsaturated ndashhorizontal trickling filter both aerobic andanaerobic
1292011
9
Flow regimes cell layout
Surface feed unsaturated subsurface flow
1292011
10
Subsurface flow
Surface feedsurface flow
1292011
11
Performance Potential
Frequent pollutants1 Sediments - 1) settling basin design τmin gt settling
time 2) sediment accumulation ratedictates storage capacity (dredging willdictates storage capacity (dredging willrequire CWA sec 404 permit as well aseasy access) Short circuiting of flow isproblematic avoid scouring
2 Nitrogen ndash two removal mechanisms 1) burial of organic N2) d it ifi ti T fi t h i i i2) denitrification To use first mechanism maximizeplant growth and sediment accumulation (saturated soil)For denitrification anaerobic zones without shortcircuiting are important subsurface feed and flow aredesirable For feed lots initial nitrification may requireaerated flow
1292011
12
Further pollutantsPhosphorus ndash primary removal mechanisms are burial of organic
matter and sorption on oxic soils Maximize organicmatter preservation (anaerobic soils) sedimentaccumulation rate and areas with oxic sediments avoidshort circuiting ndash multiple cells desirable
Vectors amp pathogens1 Mosquitoes ndash minimize stagnant water
- utilize natural predators2 Bacteria ndash retention time adequate to kill bacteria
base on low temperature conditions- solids filtration (subsurface flow) and settling
Processes in wetlands
1292011
13
Empirical design criteria
1292011
14
Quasi-mechanistic design criteria
1 Hydrology Q ndash Q + PmiddotA - ETA = dVdt1 Hydrology Qin ndash Qout + P A - ET A = dVdt1 Darcyrsquos Law Q = KA(dhdx)
2 BOD or bacteria removal
( )175
2
3
1exp refT Tv
o
v
C A k A L w dC Q
mA specific area for bacterial growth
θ φminus⎛ ⎞= sdot minus sdot sdot sdot sdot sdot sdot sdot⎜ ⎟
⎝ ⎠⎛ ⎞
= sdot sdot sdot sdot sdot⎜ ⎟⎝ ⎠
3
dim
v p f f gm
L w d physical ensionsporosityφ
⎜ ⎟⎝ ⎠
= sdot=
Constructed Wetland or Pond
1292011
15
What functions are fulfilled
Wetland or lagoon or pond
1292011
16
References
1 U S EPA 6261-88022 Sept 1988 Design Manual1 US EPA 6261-88022 Sept 1988 Design Manual Constructed wetlands and aquatic plant systems for municipal wastewater treatment
2 Moshiri GA (ed) 1993 Constructed wetlands for water quality improvement CRC Press Boca Raton FL 632 pp
3 Hammer DA (ed) 1989 Constructed wetlands for wastewater treatment Municipal Industrial and Agricultural Lewis p g Publishers Chelsea MI 831 pp
4 Hammer DA 1997 Creating Freshwater Wetlands 2nd ed CRC Press Boca Raton FL 406 pp
1292011
8
Reasons for constructing wetlandswetlands
1 Mitigation (replacement of destroyed wetlands)2 Banking2 NPS pollution control2 NPS pollution control3 Point source pollution treatment (sewage storm water runoff
acid mine drainage ldquoindustrialrdquo waste)4 Wildlife habitat5 Wetland restoration
Flow regimes in constructed wetlands
S f flSurface flow ndasheasier but require more areatemporally amp spatially variable
Subsurface flow saturated ndashlargely anaerobic
Subsurface flow unsaturated ndashhorizontal trickling filter both aerobic andanaerobic
1292011
9
Flow regimes cell layout
Surface feed unsaturated subsurface flow
1292011
10
Subsurface flow
Surface feedsurface flow
1292011
11
Performance Potential
Frequent pollutants1 Sediments - 1) settling basin design τmin gt settling
time 2) sediment accumulation ratedictates storage capacity (dredging willdictates storage capacity (dredging willrequire CWA sec 404 permit as well aseasy access) Short circuiting of flow isproblematic avoid scouring
2 Nitrogen ndash two removal mechanisms 1) burial of organic N2) d it ifi ti T fi t h i i i2) denitrification To use first mechanism maximizeplant growth and sediment accumulation (saturated soil)For denitrification anaerobic zones without shortcircuiting are important subsurface feed and flow aredesirable For feed lots initial nitrification may requireaerated flow
1292011
12
Further pollutantsPhosphorus ndash primary removal mechanisms are burial of organic
matter and sorption on oxic soils Maximize organicmatter preservation (anaerobic soils) sedimentaccumulation rate and areas with oxic sediments avoidshort circuiting ndash multiple cells desirable
Vectors amp pathogens1 Mosquitoes ndash minimize stagnant water
- utilize natural predators2 Bacteria ndash retention time adequate to kill bacteria
base on low temperature conditions- solids filtration (subsurface flow) and settling
Processes in wetlands
1292011
13
Empirical design criteria
1292011
14
Quasi-mechanistic design criteria
1 Hydrology Q ndash Q + PmiddotA - ETA = dVdt1 Hydrology Qin ndash Qout + P A - ET A = dVdt1 Darcyrsquos Law Q = KA(dhdx)
2 BOD or bacteria removal
( )175
2
3
1exp refT Tv
o
v
C A k A L w dC Q
mA specific area for bacterial growth
θ φminus⎛ ⎞= sdot minus sdot sdot sdot sdot sdot sdot sdot⎜ ⎟
⎝ ⎠⎛ ⎞
= sdot sdot sdot sdot sdot⎜ ⎟⎝ ⎠
3
dim
v p f f gm
L w d physical ensionsporosityφ
⎜ ⎟⎝ ⎠
= sdot=
Constructed Wetland or Pond
1292011
15
What functions are fulfilled
Wetland or lagoon or pond
1292011
16
References
1 U S EPA 6261-88022 Sept 1988 Design Manual1 US EPA 6261-88022 Sept 1988 Design Manual Constructed wetlands and aquatic plant systems for municipal wastewater treatment
2 Moshiri GA (ed) 1993 Constructed wetlands for water quality improvement CRC Press Boca Raton FL 632 pp
3 Hammer DA (ed) 1989 Constructed wetlands for wastewater treatment Municipal Industrial and Agricultural Lewis p g Publishers Chelsea MI 831 pp
4 Hammer DA 1997 Creating Freshwater Wetlands 2nd ed CRC Press Boca Raton FL 406 pp
1292011
9
Flow regimes cell layout
Surface feed unsaturated subsurface flow
1292011
10
Subsurface flow
Surface feedsurface flow
1292011
11
Performance Potential
Frequent pollutants1 Sediments - 1) settling basin design τmin gt settling
time 2) sediment accumulation ratedictates storage capacity (dredging willdictates storage capacity (dredging willrequire CWA sec 404 permit as well aseasy access) Short circuiting of flow isproblematic avoid scouring
2 Nitrogen ndash two removal mechanisms 1) burial of organic N2) d it ifi ti T fi t h i i i2) denitrification To use first mechanism maximizeplant growth and sediment accumulation (saturated soil)For denitrification anaerobic zones without shortcircuiting are important subsurface feed and flow aredesirable For feed lots initial nitrification may requireaerated flow
1292011
12
Further pollutantsPhosphorus ndash primary removal mechanisms are burial of organic
matter and sorption on oxic soils Maximize organicmatter preservation (anaerobic soils) sedimentaccumulation rate and areas with oxic sediments avoidshort circuiting ndash multiple cells desirable
Vectors amp pathogens1 Mosquitoes ndash minimize stagnant water
- utilize natural predators2 Bacteria ndash retention time adequate to kill bacteria
base on low temperature conditions- solids filtration (subsurface flow) and settling
Processes in wetlands
1292011
13
Empirical design criteria
1292011
14
Quasi-mechanistic design criteria
1 Hydrology Q ndash Q + PmiddotA - ETA = dVdt1 Hydrology Qin ndash Qout + P A - ET A = dVdt1 Darcyrsquos Law Q = KA(dhdx)
2 BOD or bacteria removal
( )175
2
3
1exp refT Tv
o
v
C A k A L w dC Q
mA specific area for bacterial growth
θ φminus⎛ ⎞= sdot minus sdot sdot sdot sdot sdot sdot sdot⎜ ⎟
⎝ ⎠⎛ ⎞
= sdot sdot sdot sdot sdot⎜ ⎟⎝ ⎠
3
dim
v p f f gm
L w d physical ensionsporosityφ
⎜ ⎟⎝ ⎠
= sdot=
Constructed Wetland or Pond
1292011
15
What functions are fulfilled
Wetland or lagoon or pond
1292011
16
References
1 U S EPA 6261-88022 Sept 1988 Design Manual1 US EPA 6261-88022 Sept 1988 Design Manual Constructed wetlands and aquatic plant systems for municipal wastewater treatment
2 Moshiri GA (ed) 1993 Constructed wetlands for water quality improvement CRC Press Boca Raton FL 632 pp
3 Hammer DA (ed) 1989 Constructed wetlands for wastewater treatment Municipal Industrial and Agricultural Lewis p g Publishers Chelsea MI 831 pp
4 Hammer DA 1997 Creating Freshwater Wetlands 2nd ed CRC Press Boca Raton FL 406 pp
1292011
10
Subsurface flow
Surface feedsurface flow
1292011
11
Performance Potential
Frequent pollutants1 Sediments - 1) settling basin design τmin gt settling
time 2) sediment accumulation ratedictates storage capacity (dredging willdictates storage capacity (dredging willrequire CWA sec 404 permit as well aseasy access) Short circuiting of flow isproblematic avoid scouring
2 Nitrogen ndash two removal mechanisms 1) burial of organic N2) d it ifi ti T fi t h i i i2) denitrification To use first mechanism maximizeplant growth and sediment accumulation (saturated soil)For denitrification anaerobic zones without shortcircuiting are important subsurface feed and flow aredesirable For feed lots initial nitrification may requireaerated flow
1292011
12
Further pollutantsPhosphorus ndash primary removal mechanisms are burial of organic
matter and sorption on oxic soils Maximize organicmatter preservation (anaerobic soils) sedimentaccumulation rate and areas with oxic sediments avoidshort circuiting ndash multiple cells desirable
Vectors amp pathogens1 Mosquitoes ndash minimize stagnant water
- utilize natural predators2 Bacteria ndash retention time adequate to kill bacteria
base on low temperature conditions- solids filtration (subsurface flow) and settling
Processes in wetlands
1292011
13
Empirical design criteria
1292011
14
Quasi-mechanistic design criteria
1 Hydrology Q ndash Q + PmiddotA - ETA = dVdt1 Hydrology Qin ndash Qout + P A - ET A = dVdt1 Darcyrsquos Law Q = KA(dhdx)
2 BOD or bacteria removal
( )175
2
3
1exp refT Tv
o
v
C A k A L w dC Q
mA specific area for bacterial growth
θ φminus⎛ ⎞= sdot minus sdot sdot sdot sdot sdot sdot sdot⎜ ⎟
⎝ ⎠⎛ ⎞
= sdot sdot sdot sdot sdot⎜ ⎟⎝ ⎠
3
dim
v p f f gm
L w d physical ensionsporosityφ
⎜ ⎟⎝ ⎠
= sdot=
Constructed Wetland or Pond
1292011
15
What functions are fulfilled
Wetland or lagoon or pond
1292011
16
References
1 U S EPA 6261-88022 Sept 1988 Design Manual1 US EPA 6261-88022 Sept 1988 Design Manual Constructed wetlands and aquatic plant systems for municipal wastewater treatment
2 Moshiri GA (ed) 1993 Constructed wetlands for water quality improvement CRC Press Boca Raton FL 632 pp
3 Hammer DA (ed) 1989 Constructed wetlands for wastewater treatment Municipal Industrial and Agricultural Lewis p g Publishers Chelsea MI 831 pp
4 Hammer DA 1997 Creating Freshwater Wetlands 2nd ed CRC Press Boca Raton FL 406 pp
1292011
11
Performance Potential
Frequent pollutants1 Sediments - 1) settling basin design τmin gt settling
time 2) sediment accumulation ratedictates storage capacity (dredging willdictates storage capacity (dredging willrequire CWA sec 404 permit as well aseasy access) Short circuiting of flow isproblematic avoid scouring
2 Nitrogen ndash two removal mechanisms 1) burial of organic N2) d it ifi ti T fi t h i i i2) denitrification To use first mechanism maximizeplant growth and sediment accumulation (saturated soil)For denitrification anaerobic zones without shortcircuiting are important subsurface feed and flow aredesirable For feed lots initial nitrification may requireaerated flow
1292011
12
Further pollutantsPhosphorus ndash primary removal mechanisms are burial of organic
matter and sorption on oxic soils Maximize organicmatter preservation (anaerobic soils) sedimentaccumulation rate and areas with oxic sediments avoidshort circuiting ndash multiple cells desirable
Vectors amp pathogens1 Mosquitoes ndash minimize stagnant water
- utilize natural predators2 Bacteria ndash retention time adequate to kill bacteria
base on low temperature conditions- solids filtration (subsurface flow) and settling
Processes in wetlands
1292011
13
Empirical design criteria
1292011
14
Quasi-mechanistic design criteria
1 Hydrology Q ndash Q + PmiddotA - ETA = dVdt1 Hydrology Qin ndash Qout + P A - ET A = dVdt1 Darcyrsquos Law Q = KA(dhdx)
2 BOD or bacteria removal
( )175
2
3
1exp refT Tv
o
v
C A k A L w dC Q
mA specific area for bacterial growth
θ φminus⎛ ⎞= sdot minus sdot sdot sdot sdot sdot sdot sdot⎜ ⎟
⎝ ⎠⎛ ⎞
= sdot sdot sdot sdot sdot⎜ ⎟⎝ ⎠
3
dim
v p f f gm
L w d physical ensionsporosityφ
⎜ ⎟⎝ ⎠
= sdot=
Constructed Wetland or Pond
1292011
15
What functions are fulfilled
Wetland or lagoon or pond
1292011
16
References
1 U S EPA 6261-88022 Sept 1988 Design Manual1 US EPA 6261-88022 Sept 1988 Design Manual Constructed wetlands and aquatic plant systems for municipal wastewater treatment
2 Moshiri GA (ed) 1993 Constructed wetlands for water quality improvement CRC Press Boca Raton FL 632 pp
3 Hammer DA (ed) 1989 Constructed wetlands for wastewater treatment Municipal Industrial and Agricultural Lewis p g Publishers Chelsea MI 831 pp
4 Hammer DA 1997 Creating Freshwater Wetlands 2nd ed CRC Press Boca Raton FL 406 pp
1292011
12
Further pollutantsPhosphorus ndash primary removal mechanisms are burial of organic
matter and sorption on oxic soils Maximize organicmatter preservation (anaerobic soils) sedimentaccumulation rate and areas with oxic sediments avoidshort circuiting ndash multiple cells desirable
Vectors amp pathogens1 Mosquitoes ndash minimize stagnant water
- utilize natural predators2 Bacteria ndash retention time adequate to kill bacteria
base on low temperature conditions- solids filtration (subsurface flow) and settling
Processes in wetlands
1292011
13
Empirical design criteria
1292011
14
Quasi-mechanistic design criteria
1 Hydrology Q ndash Q + PmiddotA - ETA = dVdt1 Hydrology Qin ndash Qout + P A - ET A = dVdt1 Darcyrsquos Law Q = KA(dhdx)
2 BOD or bacteria removal
( )175
2
3
1exp refT Tv
o
v
C A k A L w dC Q
mA specific area for bacterial growth
θ φminus⎛ ⎞= sdot minus sdot sdot sdot sdot sdot sdot sdot⎜ ⎟
⎝ ⎠⎛ ⎞
= sdot sdot sdot sdot sdot⎜ ⎟⎝ ⎠
3
dim
v p f f gm
L w d physical ensionsporosityφ
⎜ ⎟⎝ ⎠
= sdot=
Constructed Wetland or Pond
1292011
15
What functions are fulfilled
Wetland or lagoon or pond
1292011
16
References
1 U S EPA 6261-88022 Sept 1988 Design Manual1 US EPA 6261-88022 Sept 1988 Design Manual Constructed wetlands and aquatic plant systems for municipal wastewater treatment
2 Moshiri GA (ed) 1993 Constructed wetlands for water quality improvement CRC Press Boca Raton FL 632 pp
3 Hammer DA (ed) 1989 Constructed wetlands for wastewater treatment Municipal Industrial and Agricultural Lewis p g Publishers Chelsea MI 831 pp
4 Hammer DA 1997 Creating Freshwater Wetlands 2nd ed CRC Press Boca Raton FL 406 pp
1292011
13
Empirical design criteria
1292011
14
Quasi-mechanistic design criteria
1 Hydrology Q ndash Q + PmiddotA - ETA = dVdt1 Hydrology Qin ndash Qout + P A - ET A = dVdt1 Darcyrsquos Law Q = KA(dhdx)
2 BOD or bacteria removal
( )175
2
3
1exp refT Tv
o
v
C A k A L w dC Q
mA specific area for bacterial growth
θ φminus⎛ ⎞= sdot minus sdot sdot sdot sdot sdot sdot sdot⎜ ⎟
⎝ ⎠⎛ ⎞
= sdot sdot sdot sdot sdot⎜ ⎟⎝ ⎠
3
dim
v p f f gm
L w d physical ensionsporosityφ
⎜ ⎟⎝ ⎠
= sdot=
Constructed Wetland or Pond
1292011
15
What functions are fulfilled
Wetland or lagoon or pond
1292011
16
References
1 U S EPA 6261-88022 Sept 1988 Design Manual1 US EPA 6261-88022 Sept 1988 Design Manual Constructed wetlands and aquatic plant systems for municipal wastewater treatment
2 Moshiri GA (ed) 1993 Constructed wetlands for water quality improvement CRC Press Boca Raton FL 632 pp
3 Hammer DA (ed) 1989 Constructed wetlands for wastewater treatment Municipal Industrial and Agricultural Lewis p g Publishers Chelsea MI 831 pp
4 Hammer DA 1997 Creating Freshwater Wetlands 2nd ed CRC Press Boca Raton FL 406 pp
1292011
14
Quasi-mechanistic design criteria
1 Hydrology Q ndash Q + PmiddotA - ETA = dVdt1 Hydrology Qin ndash Qout + P A - ET A = dVdt1 Darcyrsquos Law Q = KA(dhdx)
2 BOD or bacteria removal
( )175
2
3
1exp refT Tv
o
v
C A k A L w dC Q
mA specific area for bacterial growth
θ φminus⎛ ⎞= sdot minus sdot sdot sdot sdot sdot sdot sdot⎜ ⎟
⎝ ⎠⎛ ⎞
= sdot sdot sdot sdot sdot⎜ ⎟⎝ ⎠
3
dim
v p f f gm
L w d physical ensionsporosityφ
⎜ ⎟⎝ ⎠
= sdot=
Constructed Wetland or Pond
1292011
15
What functions are fulfilled
Wetland or lagoon or pond
1292011
16
References
1 U S EPA 6261-88022 Sept 1988 Design Manual1 US EPA 6261-88022 Sept 1988 Design Manual Constructed wetlands and aquatic plant systems for municipal wastewater treatment
2 Moshiri GA (ed) 1993 Constructed wetlands for water quality improvement CRC Press Boca Raton FL 632 pp
3 Hammer DA (ed) 1989 Constructed wetlands for wastewater treatment Municipal Industrial and Agricultural Lewis p g Publishers Chelsea MI 831 pp
4 Hammer DA 1997 Creating Freshwater Wetlands 2nd ed CRC Press Boca Raton FL 406 pp
1292011
15
What functions are fulfilled
Wetland or lagoon or pond
1292011
16
References
1 U S EPA 6261-88022 Sept 1988 Design Manual1 US EPA 6261-88022 Sept 1988 Design Manual Constructed wetlands and aquatic plant systems for municipal wastewater treatment
2 Moshiri GA (ed) 1993 Constructed wetlands for water quality improvement CRC Press Boca Raton FL 632 pp
3 Hammer DA (ed) 1989 Constructed wetlands for wastewater treatment Municipal Industrial and Agricultural Lewis p g Publishers Chelsea MI 831 pp
4 Hammer DA 1997 Creating Freshwater Wetlands 2nd ed CRC Press Boca Raton FL 406 pp
1292011
16
References
1 U S EPA 6261-88022 Sept 1988 Design Manual1 US EPA 6261-88022 Sept 1988 Design Manual Constructed wetlands and aquatic plant systems for municipal wastewater treatment
2 Moshiri GA (ed) 1993 Constructed wetlands for water quality improvement CRC Press Boca Raton FL 632 pp
3 Hammer DA (ed) 1989 Constructed wetlands for wastewater treatment Municipal Industrial and Agricultural Lewis p g Publishers Chelsea MI 831 pp
4 Hammer DA 1997 Creating Freshwater Wetlands 2nd ed CRC Press Boca Raton FL 406 pp