Ricky Ebersohl SSC Fall 2008

Wetlands serve to reduce and remove toxins from the environment Wetlands provide a buffer for flood control and draught Absorb and hold excess water during rainy seasons Slowly release water during drier times Wetlands provide a unique habitat for organisms of all kinds Source: North Queensland Area Consultative Committee

Aquatic plants that help to remove contaminants Broad-leafed arrowhead (Sagittaria latifolia) Lotus (Nelumbo lutea) Elodea (Elodea canadensis) Pickerelweed (Pontederia cordata) Wild rice (Zizania aquatica) Mosquito fern (Azolla mexicana) Wild celery (Vallisneria americana) Big duckweed (Spirodela polyrhiza) Lesser duckweed (Lemna minor) Source:

Organic nitrogen Aerobic/anaerobic (ammonification) Affects oxygen levels in the wetlands Removal – mineralization into inorganic forms Ammonia/ammonium/nitrates Toxicity to fish Nitrates can decrease the blood’s ability to transport oxygen Removal – in soils, nitrification (aerobic) and denitrification (primarily anaerobic) and taken up by plants Source:

Phosphorus Plants Stored during the growing season Released when the plants die Soils Stored in sediments (phosphorus sink) Redox potential – wetland soils can reduce iron and release bound phosphorus Dependent largely on oxygen concentrations Source: USGS Water Resources

Purpose Storm water control and management Municipal wastewater treatment Agricultural wastewater treatment Landfill leachate management Runoff control Components Soil and drainage construction Water Aquatic plants Micro-organisms Source: Colorado State University

Advantages over conventional wetlands Generally independent of groundwater channels Purpose-specific design (efficient) Develop and mature quickly Size remains constant Source: United Nations Environment Programme

Source: City of Arcata

Primary treatment Uses multiple steps to remove larger solid objects Generates and then removes bulky sludge Aerobic and anaerobic digesters are used to stabilize sludge for removal Sludge is dried and removed Source: City of Arcata Source: United Nations Environment Programme

Secondary treatment Uses oxidation ponds and treatment wetlands Oxidation ponds Utilizes bacteria to break down organic material Utilizes algae to provide oxygen Treatments wetlands Utilizes a marsh setup Cattails and other marsh plants help remove ammonia, nitrogen, and phosphorus Reduces total and fecal coliform and settles remaining waste residue Source: City of Arcata

Tertiary treatment Enhancement marshes Final stage, in most cases Provides habitat Provides recreational facilities Lowers nutrient content Reduces BOD (measures organic matter content) Reduces effluent in a final step Resulting water can be directly released into the environment Source: City of Arcata

Disinfection Chlorination Used to destroy pathogens Removes ammonia Reduces sludge buildup Dechlorination Sulfur dioxide is used to remove chlorine from the sterilized water Resulting water is safe for release into the environment, outside of the wetlands Source: City of Arcata

Average for total dissolved solids Average for chlorine and sulfates Average for specific conductance Zero positive for coliform Zero positive for fecal bacteria Zero positive for e.coli Negative for lead Negative for copper Source:

1. Australian Natural Resource Management. “Wetland ecosystem condition: nutrients (phosphorus and nitrogen)”. indicators/inland-aquatic/wetland-condition-nutrients.html. Accessed October 26, indicators/inland-aquatic/wetland-condition-nutrients.html 2. Campbell, Craig S. and Michael H. Ogden. Constructed Wetlands in the Sustainable Landscape. John Wiley & Sons, Inc. New York, p City of Arcata – Arcata Marsh & Wildlife Sanctuary. d=47. Accessed October 25, d=47 4. City of Arcata – Drinking Water 2007 Water Quality Report. rt_2007.pdf. Accessed October 26, rt_2007.pdf 5. DeBusk, William F. “Wastewater Treatment Wetlands: Applications and Treatment Efficiency”. University of Florida, Institute of Food and Agricultural Sciences (UF/IFAS). May Hawkins, Julie. “Constructed Treatment Wetlands”. USDA-NRCS. USDA-NRCS. April 1, Kadlec, Knight, Robert H., Robert L. Treatment Wetlands. CRC Press LLC, 1996.