wetlands: restoration and creation

Wetlands:Restoration and Creation

Andrew McMillanCylphine Bresdin

Two Approaches

Treatment Municipal Industrial Agricultural Storm Water

Mitigation Policy Restore Create Aesthetics

Multiple major Functions Catchment

Slows and detours storm runoff

WETLAND FUNCTIONS

City park

Multiple major Functions Catchment

Slows and detours storm runoff Habitat

Flora Fauna microorganisms

WETLAND FUNCTIONS

Canal

Multiple major Functions Catchment

Slows and detours storm runoff Habitat

Flora Fauna microorganisms

Filtration Pollutants and toxins

WETLAND FUNCTIONS

Treatment Lagoon

Multiple major Functions Catchment

Slows and detours storm runoff Habitat

Flora Fauna microorganisms

Filtration Pollutants and toxins

Climatic effects Evens out the ambient temperature

WETLAND FUNCTIONS

Golf course

Definitions from text page 379

DEFINITIONSconsidered all wetland types

PRINCIPLES

Self sufficient over timeHabitat for aquatic and wildlife

Habitat for (re)vegetation

Surrounding environment

Transition edge effects

Micro organisms

Geomorphology

Hydrology

Purpose

Type

POLICY Clean Water Act (CWA)

Compensating for Wetland Losses Under the CWAhttp://www.nap.edu.catalog/10134.html

Legal success No-net-loss

Ecological success Location

hydrology Self regulating

succession Wetland bank

compensatory

Image from text page 380

Restore what has been lost due to human actionWetland Reserve Program1990 Farm Bill

Bottomland forestagriculture runoffPre-filterSoil stabilizationHabitat

Image from text page 389

RESTORATION

Legal responsibilitiesHidden benefits

CatchmentAestheticsEcological

CREATION

Create new to replace lost

Canyon Park Detention Pond

AESTHETICSCreated pond as landscape element

CALA Building Underwood Garden

Rain water harvesting and cycling Respite Education

Local agency over-site

CONSTRUCTEDCreated pond as backyard waste water treatment

Image from Oklahoma pamphlet on residential wetlands

Two Approaches

Treatment Municipal Industrial Agricultural Storm Water

Mitigation Policy Restore Create Aesthetics

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 SourcesWastewater Category

Origin Frequency Description

Municipal wastewater

Residential & Commercial

Continuous Urine, feces, paper, plastics, soaps, greases, household chemicals

Industrial wastewater

Industrial processes and leachates

Continuous- intermittent

Diluted solution of biodegradable and non-degradable chemicals

Agricultural wastewater

Agricultural practices (slaughter houses, feedlots, chemicals)

Continuous- intermittent

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

• Urban & suburban runoff are sometimes channelized to storm sewers to municipal treatment facilities

• Most runoff is diverted to detention ponds for treatment

Storm Waters

• 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

Restoration, Creation, and Recovery of Wetlands, Mary E. Kentula, EPAConstructed Wetlands: Using Human Ingenuity, Natural Processes to Treat Water, Build Habitat, Joe GeltWetlands, Mitsch and GosselinkCWA report available from http://www.nap.edu.catalog/10134.html

Constructed Wetlands and Aquatic Plant Systems for Municipal Wastewater Treatment, EPAConstructed Wetlands for Wastewater Treatment and Wildlife Habitat, EPATreatment Wetlands, Kadlec & KnightConstructed Wetlands for Wastewater Treatment, Donald A Hammer

Credits