Constructed Wetlands

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Constructed Wetlands
Christopher C. Camacho
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Characteristics of Wetlands

• Must have
• Hydrophytes
• Soils that are saturated, flooded or ponded long
  enough to develop anaerobic conditions.
• Hydrophilic plants
• From Reeds List
• Standing water for all or part of the year.

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Two Kinds of Wetlands

• Naturally Occurring Wetland
• Constructed Wetland

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Naturally Occurring Wetland

• Mangrove swamp on San Jose Island

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Naturally Occurring Wetland

• Two categories
• Coastal Wetland 11 million hectares
• Inland Wetland 32 million hectares

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Constructed Wetlands in the U.S

• Over 600 active projects across the United States
• In Arizona 26 on-site and constructed wetlands
  operating in the State 24 waiting to be
  approved or under construction.
• 1990 4 constructed Wetlands

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Constructed Wetland

• Wildlife Habitat
• Integral Man-made system
• Water, plants, microorganisms, soils, and air
  interact to improve water quality.
• Water treatment facility
• Filtration and water regeneration

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Uses of Constructed Wetlands

• Water Treatment facility
• Treat wastewater
• Wildlife Refuge
• Revival of species or introduction of new species
• Restored Wetland
• Under rehabilitation

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Two Systems of Constructed Wetlands

• Surface Flow System/ Free Water Wetland
• Subsurface System

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Advantages of Constructed Wetlands

• Low Construction and Operating Cost
• Cheap alternative to wastewater filtration
• High level of wastewater treatment
• Efficient treatment of wastewater
• Reduces if not eliminates odors
• Able to handle variable wastewater loadings
• Reduced land area needed for application of
  wastewater
• Wildlife habitat

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Construction Operating Cost Constructed
Wetlands vs. Chemical Treatment Facilities

• Constructed Wetlands
• 2.5 million construction cost
• Minimal supervision
• No chemical additions required
• Needs to be filtered every 10 yrs
• 100,000.00

• Chemical Treatment Facility
• 4.8 million 8.8 million (construction cost)
• Comparable size

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High Level of Wastewater Treatment

• Figure 1 - Summary results of the percentage of
  pollutants removed fromthree (3) demonstrational
  constructed wetlands. NOTE In the case
  ofnitrate nitrogen on Site 1, very little was
  present in the inflow, so little could be
  removed.
• Kenneth D. SimeralAssociate ProfessorThe Ohio
  State University

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Limitations

• Continuous supply of water is needed.
• Affected by Seasonal Weather Conditions
• Can be Destroyed by an overload of solids or
  ammonia levels
• Can remove Nutrients that can be used by crops.