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Constructed Wetlands Treatment of an Automotive Bedliner Manufacturer’s Wastewater. Art Kuljian, P.E., BCEE, Kevin Olmstead, Ph.D., P.E., Tammy Rabideau, CPG, Jamie Meikle WEFTEC 2009 October 14, 2009. Outline. Background Timeline Construction and Startup System Description
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Constructed Wetlands Treatment of an Automotive Bedliner Manufacturer’s Wastewater Art Kuljian, P.E., BCEE, Kevin Olmstead, Ph.D., P.E., Tammy Rabideau, CPG, Jamie Meikle WEFTEC 2009 October 14, 2009
Outline • Background • Timeline • Construction and Startup • System Description • Treatment Cells and Lagoons • Wetland Plantings • Tertiary Filtration • System Performance • System Observations • Summary
Background • Truck bedliner manufacturing operation in Lapeer, Michigan • Mixed sanitary and process wastewater from plastic extrusion and thermoforming operations • Previous unlined lagoon system ineffective • Restrictive groundwater discharge limits • Switched to wetland wastewater treatment • “First-in-the-State” in Michigan for an industrial application
Constructed Wetlands Advantages • Passive, self-regenerative treatment process, given proper harvesting of dominant plants • Low environmental impact • Little need for operator attention • Large buffering capacity to accommodate system variances • Habitats for wetland species • Short implementation schedule
Timeline • Characterization – June 1999 • Pilot Study – August 1999 • Design/Build Proposal – January 2000 • Begin Construction – April 2000 • System Startup – August 2000 • Phase 2 Expansion – April 2006 • Phase 2 Commissioning – October 2006 • In continuous operation since November 2000
Construction and Startup • Wetland comprised of over 27,000 native plants • Installed over 160,000 ft2 PVC liner and earth bed • Seeded startup with activated sludge from POTW • Temporary winter storage of wastewater in HDPE lined lagoons underlain with bentonite-sand layer • Final polishing in 150 ft2 tertiary sand filter building • UV disinfection prior to surface water discharge
System Description • 20,000 gallon/day (gpd) design flow rate, 90 day HRT • 4 acre lined wetland treatment system - 2 winter storage lagoons (900,000 gal.each) - 2 primary cells (0.6 acre capacity) - secondary treatment cell (2.5 acre capacity) - tertiary treatment cell (0.9 acre capacity) • Continuous downflow sand filter rated at 5 gpm/ft2 • Disinfection w/ultraviolet (UV) radiation • Flow monitoring structure and discharge to Plum Creek
System Performance • Significant treatment occurs in the primary cells: - BOD and TSS are reduced ~ 60% to 70% - NH3-N is reduced ~ 85% to 95% - Total P is reduced ~ 60% to 70% • Flowthrough, facultative treatment occurs in the primary cells, with an HRT of ~ 12 days • Vegetative growth in the secondary and tertiary cells results in mass removals for all target parameters of 90% to 95%
Site Observations • Nutrient uptake in wetland vegetation was poor during the winter months and good to excellent remainder of the year • Operations labor minimal - <2 hours/8 hour shift • Normal operation requires no chemical addition • Maintaining water operating depth of <18” is vital for emergent vegetation to occur • Presence of wildlife indicative of a healthy habitat
Performance Summary • 95% removal of BOD5, TSS, NH3-N and P is achievable • Effluent NH3-N of 0.5 mg/L and P of 0.2 mg/L • Primary cells provide equalization and treatment prior to discharge to secondary and tertiary cells • Effluent BOD5 has averaged 3 mg/L and TSS has averaged 5 mg/L since installation of the sand filter
Lessons Learned • Ensure C:N:P ratio of 100:5:1 is available in wastewater feed • Maintain wetland water temperature >50°F (10°C); otherwise, winter storage may be needed • Backwash of sand filter at 2% to 5% of flow aids insoluble nutrient removal • Periodic lamp cleaning via citric acid and/or sodium hypochlorite every 2 to 3 months • Annual harvesting of dominant plants (e.g., cattails) helps ensure variation and quantities of all species • Harvest duckweed before winter die-off to keep total P inventory in check
Contractor/Supplier Acknowledgements • Ms. Joanne Michael, Southern Tier Consulting – West Clarksville, NY • Mr. Dave Bury, North American Lining Services – Kalkaska, MI • Mr. Mark Fisher, Lighthouse Filters – Dahlonega, GA • Mr. Todd Desloover, Debarr Construction – Greenwood, MI • Mr. H. Blair Selover, Tetra Tech – Ann Arbor, MI