Constructed Wetlands for Feedlot Runoff Treatment MSAA Workshop February 2001
Acknowledgements u Canada- Manitoba Agreement on Agricultural Sustainability (Green Plan) u Cooperators: –Mr. M. Friesen, and Mr.T. Jonsson u Manitoba Agriculture u Manitoba Environment u Ducks Unlimited Canada u PFRA
Project Objectives u develop two constructed wetland projects to treat feedlot runoff u evaluate performance in treating runoff u evaluate design, cost, construction, and operation in comparison to other treatment options u assess potential for adoption of treatment wetland technology in Agro-Manitoba
Projects u Site 1 - near Riverton –300 head cow-calf operation plus finishing –runoff flows into Lake Winnipeg u Site 2 - near L. Manitoba Narrows –1500 head beef feedlot operation –runoff flows into Lake Manitoba
Site 1: Constructed Wetland
Deep Zones u Deep Zones –dispersion of influent –prevents short circuiting –solids storage –atmospheric re-aeration –fish and wildlife habitat
Site 2: Constructed Wetland Feedlot Holding Pond Wetland Cells Lake Manitoba Emergency Overflow Drain
Site 2
Wetland Control Outlet
Design Considerations u set targets for pollutant reduction u configuration and size u requirements for runoff storage u pumping requirements u siting and setback restrictions
Raw Runoff Quality
Preliminary Wetland Size Calculation Sheet
Site 1 Wetland Performance
TSS - Site 1 Wetland
BOD 5 - Site 2 Wetland
Site 2 Wetland Performance
Ammonia - Site 2 Wetland Apr mg/L
Phosphorus - Site 2 Wetland
What are the Results telling us ? u Treatment is effective u Approaching wetland background levels for NH 3, BOD, TSS u Generally meeting municipal discharge criteria u Holding Pond may be providing significant treatment in dry years
Major Cost Considerations u wetland and storage pond lining u availability and depth to clay u presence of organic soils u requirements for pumping - topography u complexity of water control u vegetation establishment u land - project sizing and excavation costs u muskrat control
Summary u Two projects built u Wetlands performing well u Holding Pond may provide significant treatment in dry years u Muskrats can be a problem u Monitoring continuing