Wetlands:
Restoration and Creation
Andrew McMillan
Cylphine Bresdin
Two Approaches

Mitigation




Policy
Restore
Create
Aesthetics

Treatment




Municipal
Industrial
Agricultural
Storm Water
WETLAND FUNCTIONS

Multiple major Functions

Catchment

Slows and detours storm runoff
City park
WETLAND FUNCTIONS

Multiple major Functions

Catchment


Slows and detours storm runoff
Habitat



Flora
Fauna
microorganisms
Canal
WETLAND FUNCTIONS

Multiple major Functions

Catchment


Habitat




Slows and detours storm runoff
Flora
Fauna
microorganisms
Filtration

Pollutants and toxins
Treatment Lagoon
WETLAND FUNCTIONS

Multiple major Functions

Catchment


Habitat




Flora
Fauna
microorganisms
Filtration


Slows and detours storm runoff
Pollutants and toxins
Climatic effects

Evens out the ambient temperature
Golf course
DEFINITIONS
considered all wetland types
MITIGATION- to make less harsh
RESTORATION- return to prior existing condition
CREATION- conversion (by human action) of suitable land
CONSTRUCTED- a type of creation for the
purpose of water treatment
ENHANCEMENT- alters functional microhabitat relationships
Definitions from text page 379
PRINCIPLES
Self sufficient over time
Habitat for aquatic and wildlife
Habitat for (re)vegetation
Surrounding environment
Transition edge effects
Micro organisms
Geomorphology
Hydrology
Purpose
Type
POLICY

Clean Water Act (CWA)


Legal success


Compensating for Wetland Losses Under the CWA
http://www.nap.edu.catalog/10134.html
No-net-loss
Ecological success

Location


Self regulating


hydrology
succession
Wetland bank

compensatory
Image from text page 380
RESTORATION
Restore what has been lost due to human action
Wetland Reserve Program
1990 Farm Bill

Bottomland forest
agriculture runoff
Pre-filter
Soil stabilization
Habitat

Image from text page 389
CREATION
Legal responsibilities
Hidden benefits

Catchment
Aesthetics
Ecological

Canyon Park Detention Pond

Create new to replace lost
AESTHETICS
Created pond as landscape element


CALA Building Underwood Garden

Rain water harvesting and cycling
Respite
Education
CONSTRUCTED
Created pond as backyard waste water treatment
Image from Oklahoma pamphlet on residential wetlands

Local agency over-site
Two Approaches

Mitigation




Policy
Restore
Create
Aesthetics

Treatment




Municipal
Industrial
Agricultural
Storm Water
Wetland Functions



Major Function: water filtration
Water will slow trapping suspended solids by
vegetation and settling out
Pollutants are transformed to less soluble
forms


Taken up by plants or will become inactive
Microorganisms thrive in wetland environment

Microorganisms assist in transforming and
removing pollutants from aquatic systems
Wastewater Sources
Wastewater
Category
Origin
Frequency
Description
Municipal
wastewater
Residential &
Commercial
Continuous
Urine, feces, paper,
plastics, soaps,
greases, household
chemicals
Industrial
wastewater
Industrial processes Continuousand leachates
intermittent
Diluted solution of
biodegradable and
non-degradable
chemicals
Agricultural
wastewater
Agricultural
practices (slaughter
houses, feedlots,
chemicals)
Continuousintermittent
Diluted solution of
biodegradable
compounds
Storm waters
Runoff from urban,
suburban, & rural
areas
Intermittent
Diluted mixtures of
mineral & organic
solids, dissolved
salts, nutrients, and
trace constituents
Municipal Wastewater
Industrial Wastewater
• Small percentage can discharge wastewaters
for wetland systems for treatment
– Requires pretreatment
• Most contain toxic constituents at toxic conc.
detrimental to wildlife & wetland treatment
systems
Agricultural
Wastewater
• Receives minimal
treatment
• Usually through lagoons
• Treatment wetland
systems are important
for concentrated &
pretreated agricultural
wastewaters
Storm Waters
• Urban & suburban
runoff are sometimes
channelized to storm
sewers to municipal
treatment facilities
• Most runoff is diverted
to detention ponds for
treatment
• Nitrogen Removal
• Nitrogen Removal
• Phosphorous Removal
• Nitrogen Removal
• Phosphorous Removal
• BOD Removal
• Nitrogen Removal
• Phosphorous Removal
• BOD Removal
• Metals Removal
When to construct wetlands for
treatment?
• Affordable
– Total costs: operation, maintenance, and
depreciation are financially feasible
• Operable
– Can operation be sustained with local labor and
support
• Reliable
– Will system be efficient at maintain effluent
quality requirements consistently
When to construct wetlands for
treatment?
• Affordable
– Total costs: operation, maintenance, and
depreciation are financially feasible
• Operable
– Can operation be sustained with local labor and
support
• Reliable
– Will system be efficient at maintain effluent
quality requirements consistently
Free Water Surface &
Subsurface Flow Systems
Free Water Surface &
Subsurface Flow Systems
Free Water Surface &
Subsurface Flow Systems
Carolina Bays: Horry County, SC
• Treatment plant will
discharge 2.5 mgd of
wastewater
– Discharge 1in/week
• Slowly released after
primary and secondary
treatment for tertiary
treatment
• 4-Bays; Alternate flow
based upon flow rate
and condition of bays
Carolina Bays: Horry County, SC
• Treatment plant will
discharge 2.5 mgd of
wastewater
– Discharge 1in/week
• Slowly released after
primary and secondary
treatment for tertiary
treatment
• 4-Bays; Alternate flow
based upon flow rate
and condition of bays
Fort Deposit, AL
• Rely majority on
microorganisms to
breakdown organic matter
and nutrients
• Cells constructed to
simulate natural wetlands
• System is designed for the
retention time of
wastewater to be ~30 days
– Average decomposition rate
varies upon season therefore
retention time can be
adjusted by effluent
adjustment
Fort Deposit, AL
• Rely majority on
microorganisms to
breakdown organic matter
and nutrients
• Cells constructed to
simulate natural wetlands
• System is designed for the
retention time of
wastewater to be ~30 days
– Average decomposition rate
varies upon season therefore
retention time can be
adjusted by effluent
adjustment
Fort Deposit, AL
• Rely majority on
microorganisms to
breakdown organic matter
and nutrients
• Cells constructed to
simulate natural wetlands
• System is designed for the
retention time of
wastewater to be ~30 days
– Average decomposition rate
varies upon season therefore
retention time can be
adjusted by effluent
adjustment
Conclusion
• Wastewater treatment wetlands are not the
solution to all water quality issues
• Although thousands of constructed wetlands
prove this process of treatment is an
appropriate approach for a number of
contaminants based upon the given situation
• Several factors should be considered prior to
designing and building
Wetlands: Restoration and Creation
Credits
 Constructed Wetlands and
Aquatic Plant Systems for
Municipal Wastewater
Treatment, EPA
Constructed Wetlands for
Wastewater Treatment and
Wildlife Habitat, EPA
Treatment Wetlands, Kadlec &
Knight
Constructed Wetlands for
Wastewater Treatment, Donald A
Hammer
 Restoration, Creation, and
Recovery of Wetlands, Mary E.
Kentula, EPA
Constructed Wetlands: Using
Human Ingenuity, Natural
Processes to Treat Water, Build
Habitat, Joe Gelt
Wetlands, Mitsch and Gosselink
CWA report available from
http://www.nap.edu.catalog/10
134.html