Since its construction in 2017, stormwater samples have been taken at the Whitaker Treatment Wetlands in White Bear Township. Stormwater runoff from 640 acres of neighborhood drain to Whitaker Pond, located near Columbia Park. A pump directs water from the pond's forebay into the system of three wetland treatment cells. These samples inform us about how water is filtered through the various cell materials. The wetland cells consist of different compositions of concrete, peat, tire crumb, and silty clay. As water moves through the system, over 70 samples are taken at different depths in the cells, which we call the 'treatment train.'

Initial data is showing that the cells are effective in treating E. coli bacteria, total suspended solids, phosphorus, and nitrates. Post treatment samples at the end of the treatment train trend towards lower concentrations than pre-treatment samples. Spontaneous outliers also exist in the data, which are still under investigation in terms of how they occur. Several theories are outlined in our initial findings summary. The final report will be completed in Summer, 2020. 

• Initial findings summary
• Whitaker Treatment Wetlands project page

Cell Composition: 

• Control cell: 80% washed clean concrete sand, 20% sphagnum fuscum peat. Blend is pH stabilized with lime. No plants above the cell.
• Experimental cell 1: 10% tire crumbs, 85% blend of (80-20) washed clean concrete sand and sphagnum fuscum peat, 5% silty clay, pH stabilized with lime. Cell planted with wetlands plants.
  
• Experimental cell 2: 20% tire crumbs, 75% blend of (80-20) washed clean concrete sand and sphagnum fuscum peat, 5% silty clay, pH stabilized with lime. Cell planted with wetlands plants.