1. EWRI - Kansas City - 2009 Construction and Performance of Bioretention Cells G.O. Brown, R.A. Chavez, D.E. Storm, and M.D. Smolen

2. EWRI – Kansas City - 2009 Objectives  Demonstrate use of bioretention cells to improve water quality; primarily P reduction.  Develop simple to follow design procedures.  Quantify cell hydrology.  Long-term test of fly ash in filter media. 8: at Grove on Grand Lake 2: at Stillwater, including a control pair

3. EWRI – Kansas City - 2009 General Design  3% to 5% of area.  Sized for runoff:  ½” in pool  ½” in filter  1’ topsoil.  Sand plug on 25% of surface for infiltration.  Filter media a blend of sand and 5% fly ash.  Overflow designed for 50 year, 1 hour storm.

4. EWRI – Kansas City - 2009 A high-tech hole in the ground

5. EWRI – Kansas City - 2009 Infiltration plugs minimize standing water  Designed to only pond water for 24 hr.  Addition of sand “plugs” on surface compensate for lower conductivity of top soil.  25% of surface layer are sand plugs with a specification that none touch.  Proved to be easy to construct and effective. plug

6. EWRI – Kansas City - 2009 Class C fly ash significantly reduces P and metals in effluent  Batch sorption for Kd  Column experiments simulated leaching within the cell.  BCTs were fitted to find transport parameters.  Long-term effluent modeled with fitted parameters.

7. EWRI – Kansas City - 2009 Phosphorous adsorption K d, mL/gRetardation Peat moss-5.81 Teller loam0.413 Dougherty sand2.111 Expanded shale (MO)1.27 Limestone1260 Expanded shale (KS)2801,400 Class C Fly ash218011,000

8. EWRI – Kansas City - 2009 Fly ash will provide long-term P reductions Effluent P Concentration Exceeds Lifetime, yr PavementLawn 0.037 mg/L411 0.5 mg/L1235 0.95 mg/L3699 Lifetime of filter calculated assuming 1 ppm P inflow Runoff volume from pavement will be higher than lawns. Assumes reversible adsorption.

9. EWRI – Kansas City - 2009 Fly ash significantly reduces K  Adding fly ash decreased the hydraulic conductivity of the sand exponentially  Maximum 5% fly ash in Dougherty K s =3.6 cm/hr 5.0% fly ash Hydraulic conductivity of sand – fly ash mix.

10. EWRI – Kansas City - 2009 Plantings  Wet and dry tolerant  No nitrogen fixers  No invasive species  Low-maintenance requirements  Offer a color variety  Plants had to be easily attainable and replaceable  Included some native species in the plant list.

11. EWRI – Kansas City - 2009 Lots of discussion about the plants… Plant TypeSurface Area % Trees8 to 10 Shrubs15 to 20 Flowering Perennials1 to 5 Ornamental Grasses10 to 15 Rock Accents1 to 5 Of course, you could just plant grass. Heritage River Birch

12. EWRI – Kansas City - 2009 Constructed Cells Land Use Drainage Area (acres) Volume (m3) Elm Creek PlazaPaved0.62128 Lendonwood GardensTurf0.5419 Grove High SchoolPaved0.65161 Grand Lake Association Turf & Paved 1.90435 Cherokee Queen RiverboatsPaved0.45108 Spicer ResidenceTurf0.3993 Clark ResidenceTurf0.1827 Early Childhood CenterTurf0.1170 OSU Botanical Gardens, Cell APaved0.3266 OSU Botanical Gardens, Cell BPaved0.90208

13. EWRI – Kansas City - 2009 Construction

14. EWRI – Kansas City - 2009 Construction costs $7,500 + $51* volume $1,600 * $47 * volume

15. EWRI – Kansas City - 2009 Mixing fly ash proved difficult

16. EWRI – Kansas City - 2009 Wide distribution in fly ash

17. EWRI – Kansas City - 2009 Hydraulic testing

18. EWRI – Kansas City - 2009 30 % reduction in peak flow

19. EWRI – Kansas City - 2009 Water Quality Data are Inconclusive  Water quality data collected to date are generally inadequate to draw strong conclusions.  Problems arise due to the long response time of these cells and the difficultly of measuring both inflows and outflows over extended periods.  Long-term, we will take core samples of the cells and determine the species and quantity of pollutants trapped.  A comparison between the fly ash and sand filter control is possible for the initial operation.

20. EWRI – Kansas City - 2009 Impact of fly ash on effluent ParameterCellNMeanSt Dev pHControl87.580.450 Fly Ash69.780.436 NO3-N (mg/l) Control83.442.53 Fly Ash65.953.03 Ortho-P (mg/l) Control80.1150.0441 Fly Ash60.0630.0816 Fe (mg/l) Control82.292.85 Fly Ash60.1220.046 Cu (mg/l) Control8<0.020.007 Fly Ash60.0220.004 Pb (mg/l) Control8<0.020.002 Fly Ash6<0.020.016

21. EWRI – Kansas City - 2009 Two-sample T-test (95%) ParameterT-ValueP-ValueDF Significant Difference? pH-9.260.00011Yes (Higher) NO3-N-1.640.1359No Ortho-P3.240.0147Yes (Lower) Fe2.150.0697No Cu-3.050.01111Yes (Higher) Pb-1.090.3265No

22. EWRI – Kansas City - 2009 Next steps  Finish analysis of cell hydrology.  Quantify impact of the spatial variability in conductivity.  Perform more field tests.  Model results.  Relate to watershed hydrology.  Sample cells to determine retention of pollutants.  Explore filter additives that will reduce N.

23. EWRI – Kansas City - 2009 Acknowledgements  Funding for this project was provided by the Oklahoma Conservation Commission as part of a U.S. EPA Region VI, 319h grant.  Fly ash donated by Grand River Dam Authority.  Modeling by Reid Christianson

24. EWRI – Kansas City - 2009